Matching entries: 0
settings...
Aksakal F, Shvets N, Khairullina V and Dimoglo A (2016), "Structural and Electronic Factors Influencing the Selective Inhibition of COX-2", Mini-Reviews in Medicinal Chemistry. Vol. 16(7), pp. 579-594.
Abstract: Structural and electronic factors influencing the inhibition of cyclooxygenase-1 and -2 (COX-1/COX-2) were studied by means of Electronic-Topological Method combined with Neural Networks (ETM-NN), molecular docking and Density Functional Theory (DFT). A series of structurally diverse compounds containing 209 molecules were classified in accordance with their inhibiting properties, as selectively inhibiting and non-selectively inhibiting COX-2 receptor agents (110 and 99 molecules, correspondingly). The results obtained from the ETM-NN calculations gave us possibility of selecting those pharmacophoric molecular fragments, which allow for the search of new selective inhibitors of COX-2 with high probability of realization. The final selection of pharmacophores and anti-pharmacophores found was taken as a basis for a system designed for the COX-2 inhibitory activity prediction. Analysis of the electron density distribution showed that more effective binding with COX-2 receptor was observed for selective inhibitors. To make an assessment of these interactions, calculations of stabilization energies were carried out for the ligand-receptor complexes. From the results of the docking and from the analysis of electronic structures of active sites of enzymes, some peculiarities of ligand-receptor binding and its influence on the selectivity of the COX-2 relative to COX-1 inhibition were elucidated. 95% of compounds were recognized correctly, as the most active ones, by the system of prediction designed. Thus, the system being the result of the study is capable of predicting the selective inhibitory activity of COX-2 successfully. As a consequence, it can be used both for computer screening and synthesis of potent inhibitors of COX-2 with molecular skeletons that may vary considerably.
BibTeX:
@article{Aksakal2016,
  author = {Aksakal, F. and Shvets, N. and Khairullina, V. and Dimoglo, A.},
  title = {Structural and Electronic Factors Influencing the Selective Inhibition of COX-2},
  journal = {Mini-Reviews in Medicinal Chemistry},
  year = {2016},
  volume = {16},
  number = {7},
  pages = {579--594},
  url = {://WOS:000372787600006},
  doi = {10.2174/1389557515666151016124503}
}
Aydiner C, Sen U, Koseoglu-Imer DY and Dogan EC (2016), "Hierarchical prioritization of innovative treatment systems for sustainable dairy wastewater management", Journal of Cleaner Production. Vol. 112, pp. 4605-4617.
Abstract: Multiple criteria decision making is an effective approach that can be successfully used for revealing eco-innovative solutions in industrial wastewater treatment by prioritizing various promising technologies. Besides, eligible researches on emerging membrane processes viz., forward osmosis and membrane distillation are gaining widespread interest in scientific communities focused on reclamation, recovery and reuse of industrial wastewaters. In this study, the preferability of four innovative systems compared to a traditional system was hierarchically prioritized for environmentally benign treatment and utilization of dairy industry wastewater using the most common tool in multi-criteria decision making analysis, analytical hierarchy process. The analyses were attributed to the preferences classified with regard to the technical, economic and environmental aspects of the alternatives. Despite the existence of both greatest importance of energy consumption and higher energy requirements of novel solutions, major prominent features to be provided by real-scale applications of innovative systems were determined as more valuable multiple outcomes in environmental protection and economic profit. The sensitivity analysis to evaluate how the variations in the predefined weights of attributes influence the preference priorities indicated that the decision prioritization analysis on the novel technology selection was sufficiently sensitive to all the main evaluation criteria. This study proved that novel membrane technologies have more preferable features in dairy wastewater treatment by further whey utilization and waste minimization and more effective industrial water reuse, especially in case of waste heat usage in membrane distillation. Finally, sustainable dairy wastewater management in a more desirable manner than now could be accomplished by means of technically highly efficient, economically cost-effective and environmentally eco-innovative achievements. (C) 2015 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Aydiner2016,
  author = {Aydiner, C. and Sen, U. and Koseoglu-Imer, D. Y. and Dogan, E. C.},
  title = {Hierarchical prioritization of innovative treatment systems for sustainable dairy wastewater management},
  journal = {Journal of Cleaner Production},
  year = {2016},
  volume = {112},
  pages = {4605--4617},
  url = {://WOS:000368207500099},
  doi = {10.1016/j.jclepro.2015.08.107}
}
Barisci S, Ulu F, Sillanpaa M and Dimoglo A (2016), "The usage of different forms of ferrate (VI) ion for amoxicillin and ciprofloxacin removal: density functional theory based modelling of redox decomposition", Journal of Chemical Technology and Biotechnology. Vol. 91(1), pp. 257-266.
Abstract: BACKGROUND: Decomposition of amoxicillin (AMX) and ciprofloxacin (CIP) in aqueous suspensions by two forms of ferrate (VI) were investigated. The effect of the initial concentration of antibiotics, pH, and ferrate (VI) dosage were examined. Model calculations were made by the Density Functional Theory (DFT) method (RB3LYP) taking into account the environmental parameters. LanL2DZ and 6-311G(++)(d, p) were taken as basic functions for the calculations. This was followed by analysis of two redox decomposition mechanisms of the ferrate ion, with the O-2 molecule formation and electron density distribution, and the reaction mechanism of superoxide particle formation, which participates in the AMX and CIP oxidation process. RESULTS: Ferrate (VI) degraded CIP more effciently than AMX in both forms. Electrogenerated ferrate (VI) was more efficient than direct use of its solid form. The removal efficiencies of CIP and AMX by electrogenerated ferrate (VI) were 80.9% and 63.7%, respectively. CONCLUSION: This study demonstrates that ferrate (VI), with its high oxidizing capacity and coagulation effect, could be applied to the removal of antibiotics in wastewater treatment. The results of the AMX and CIP electron structure calculations demonstrate that electron transfer to the molecules leads to the formation of meta-stable states and causes the molecules to fragment. (C) 2014 Society of Chemical Industry
BibTeX:
@article{Barisci2016,
  author = {Barisci, S. and Ulu, F. and Sillanpaa, M. and Dimoglo, A.},
  title = {The usage of different forms of ferrate (VI) ion for amoxicillin and ciprofloxacin removal: density functional theory based modelling of redox decomposition},
  journal = {Journal of Chemical Technology and Biotechnology},
  year = {2016},
  volume = {91},
  number = {1},
  pages = {257--266},
  url = {://WOS:000367951400029},
  doi = {10.1002/jctb.4625}
}
Barisci S, Sarkka H, Sillanpaa M and Dimoglo A (2016), "The treatment of greywater from a restaurant by electrosynthesized ferrate (VI) ion", Desalination and Water Treatment. Vol. 57(24), pp. 11375-11385.
Abstract: Greywater reuse is an attractive alternative to sustainable water management, especially in water scarcity situations. This study sought to determine the treatment efficiency of electrochemically produced ferrate(VI) in greywater, assessing ferrate(VI) dose requirements and pH effect. Greywater originating from a restaurant was employed in this research. The treatment efficiency was investigated with regard to the chemical oxygen demand (COD), total organic carbon, turbidity, surfactants, and anions removal. The optimum performance was achieved with 75mg/L of ferrate(VI) dose at pH 7. The settling characteristics of the treated greywater were also investigated. After treatment, larger particles and zeta potential values closer to zero were observed. Electrochemically produced ferrate(VI) showed promising performance for greywater treatment.
BibTeX:
@article{Barisci2016a,
  author = {Barisci, S. and Sarkka, H. and Sillanpaa, M. and Dimoglo, A.},
  title = {The treatment of greywater from a restaurant by electrosynthesized ferrate (VI) ion},
  journal = {Desalination and Water Treatment},
  year = {2016},
  volume = {57},
  number = {24},
  pages = {11375--11385},
  url = {://WOS:000371252400040},
  doi = {10.1080/19443994.2015.1038740}
}
Barlik N, Keskinler B and Kocakerim MM (2016), "Hexavalent chromium removal performance of anionic functionalized monolithic polymers: column adsorption, regeneration and modelling", Water Science and Technology. Vol. 73(6), pp. 1279-1286.
Abstract: Anionic functionalized monolithic macro-porous polymers were used for the removal of hexavalent chromium(VI) anions from aqueous solution in column experiments. At a flux of 1.0 cm min and 30 mg Cr(VI) L-1 feed concentration, breakthrough capacity and apparent capacity were 0.066 g Cr(VI) g(-1) anionic monolith and 0.144 g Cr(VI) g(-1) anionic monolith, respectively. The degree of column utilization was found to lie in the range 41-46%. Two kinetic models, theoretical and Thomas models, were applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The simulation of the whole breakthrough curve was effective with the models. At a flux of 1.0 cm min and 30 mg Cr(VI) L-1 feed concentration, the dispersion coefficient and adsorption equilibrium constant (K) were 3.14 x 10(-7) m s(-1) and 3,840, respectively. Also, Thomas model parameters k(1) (rate constant of adsorption) and q(m) (equilibrium solid-phase concentration of sorbed solute) were 1.08 x 10(-3) L mg(-1) min(-1) and 0.124 g g(-1), respectively. After reaching equilibrium adsorption capacity, the monoliths were regenerated using 1 N HCl and were subsequently re-tested. It was found that the regeneration efficiency reduced from 98% after second usage to 97% after the third usage.
BibTeX:
@article{Barlik2016,
  author = {Barlik, N. and Keskinler, B. and Kocakerim, M. M.},
  title = {Hexavalent chromium removal performance of anionic functionalized monolithic polymers: column adsorption, regeneration and modelling},
  journal = {Water Science and Technology},
  year = {2016},
  volume = {73},
  number = {6},
  pages = {1279--1286},
  url = {://WOS:000374406800006},
  doi = {10.2166/wst.2015.602}
}
Basaran G, Kavak D, Dizge N, Asci Y, Solener M and Ozbey B (2016), "Comparative study of the removal of nickel(II) and chromium(VI) heavy metals from metal plating wastewater by two nanofiltration membranes", Desalination and Water Treatment. Vol. 57(46), pp. 21870-21880.
Abstract: The treatment of aviation industry metal plating wastewater containing Ni2+ and Cr6+ by nanofiltration was investigated in this study. Two commercial membranes (NF90 and NF270) and two membrane filtration systems (dead end and cross flow) were used. The effects of both the transmembrane pressure (10, 20, and 30 bar) and the feed pH (3.5, 7, and 10) on the membrane performance were analyzed. The rejection of both nickel and chromium ions increased with increasing pH but did not considerably change by the pressure difference for both membranes. The optimum conditions were found to be at 30 bar with a pH of 10 for both the NF90 and NF270 membranes. Under optimum conditions for the NF90 membrane, the rejection values of Ni2+ and Cr6+ were found to be 99.2 and 96.5%, respectively. For the NF270 membrane, the rejection values of Ni2+ and Cr6+ were 98.7 and 95.7%, respectively.
BibTeX:
@article{Basaran2016,
  author = {Basaran, G. and Kavak, D. and Dizge, N. and Asci, Y. and Solener, M. and Ozbey, B.},
  title = {Comparative study of the removal of nickel(II) and chromium(VI) heavy metals from metal plating wastewater by two nanofiltration membranes},
  journal = {Desalination and Water Treatment},
  year = {2016},
  volume = {57},
  number = {46},
  pages = {21870--21880},
  url = {://WOS:000384060500019},
  doi = {10.1080/19443994.2015.1127778}
}
Bayar S, Karagunduz A and Keskinler B (2016), "Influences of electroosmosis and electrophoresis on permeate flux and membrane fouling in submerged membrane bioreactors (SMBRs)", Water Science and Technology. Vol. 74(3), pp. 766-776.
Abstract: The objective of this study was to investigate the influences of electroosmosis (EO) and electrophoresis (EP) on the permeate flux in submerged membrane bioreactors. When a polymeric membrane is placed in between an anode and a cathode, both EO and EP occur simultaneously, causing enhancement in flux. Results showed that after 150 min of filtration, the permeate fluxes were 60, 115, 175 and 260 L/m(2)/h at 0, 30, 40 and 50 V, respectively. It was shown that the EO was linearly changing with increasing voltage, reaching up to 54 L/m(2)/h at 50 V. EP was found to be a significant process in removing soluble microbial products from the membrane surface, resulting in an increase in permeate flux as the filtration progressed. About 20-fold of smaller protein and carbohydrate concentrations were found in the cake layer when the electrical field (EF) was applied. However, the EF application promoted pore fouling, because of the calcium and magnesium scaling.
BibTeX:
@article{Bayar2016,
  author = {Bayar, S. and Karagunduz, A. and Keskinler, B.},
  title = {Influences of electroosmosis and electrophoresis on permeate flux and membrane fouling in submerged membrane bioreactors (SMBRs)},
  journal = {Water Science and Technology},
  year = {2016},
  volume = {74},
  number = {3},
  pages = {766--776},
  url = {://WOS:000382252700023},
  doi = {10.2166/wst.2016.280}
}
Bayar S, Karagunduz A and Keskinler B (2016), "Dead-end filtration of jet loop bioreactor and activated sludge suspensions", Desalination and Water Treatment. Vol. 57(14), pp. 6184-6192.
Abstract: Fouling is the main disadvantage of membrane processes which causes decrease in flux with time. Although there are various mathematical models representing fouling with time, a simplified approach is still needed for predicting flux decline behavior over the course of filtration. Furthermore, a comparative study to determine the effects of floc size and extracellular polymeric substance (EPS)/soluble microbial product (SMP) content for different biological suspension is important in understanding of membrane fouling. The objective of this study was to analyze filtration of two different biological suspensions and to use a simplified model to identify the effects of SMP, EPS, and floc size on fouling. The experimental data were successfully represented by a simplified model with a single fitting parameter. The fouling was independent from membrane material and pore size; however, it depended on either floc size or the EPSp content depending on the properties of biological suspension. When the floc size of the biological suspension was small (e.g. jet loop membrane bioreactor), neither EPS nor SMP contributed fouling significantly. The fouling was mainly dominated by the small floc size. However, for biological suspension with larger floc sizes (e.g. activated sludge system), the fouling was independent from floc size. For such sludge samples, the fouling was well correlated with EPSp.
BibTeX:
@article{Bayar2016a,
  author = {Bayar, S. and Karagunduz, A. and Keskinler, B.},
  title = {Dead-end filtration of jet loop bioreactor and activated sludge suspensions},
  journal = {Desalination and Water Treatment},
  year = {2016},
  volume = {57},
  number = {14},
  pages = {6184--6192},
  url = {://WOS:000368609200003},
  doi = {10.1080/19443994.2015.1008576}
}
Caliskan Y, Bektas N and Tekbas M (2016), "ANAEROBIC COMPOSTING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE", Fresenius Environmental Bulletin. Vol. 25(4), pp. 1097-1104.
Abstract: The amount of solid waste has been increasing by rapid population growth, improved technology, and economic development and changing consumption habits. This increase leads to find different municipal solid waste (MSW) management alternatives. Anaerobic composting offers a cost-effective treatment strategy to MSW management alternatives. Therefore the aim of this study was selected to investigate anaerobic composting process for food waste from catering company since large amount of organic wastes are generated from this type of sources. Anaerobic bioreactor was filled with mixed organic solid waste and monitored throughout 24 weeks. Leachate was re-circulated instead of mechanic mixing. Some parameters of leachate such as pH, COD, BOD, TKN, NH3-N, alkalinity, VFAs were analysed to gain information about biodegradability and stabilization of the anaerobic compost process. Compost which is the final product of our process also analysed at the end of the study and it was seen that the compost is stable and can be used for agricultural purposes.
BibTeX:
@article{Caliskan2016,
  author = {Caliskan, Y. and Bektas, N. and Tekbas, M.},
  title = {ANAEROBIC COMPOSTING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE},
  journal = {Fresenius Environmental Bulletin},
  year = {2016},
  volume = {25},
  number = {4},
  pages = {1097--1104},
  url = {://WOS:000375826700014}
}
Cetin B, Odabasi M and Bayram A (2016), "Wet deposition of persistent organic pollutants (POPs) in Izmir, Turkey", Environmental Science and Pollution Research. Vol. 23(9), pp. 9227-9236.
Abstract: Concentrations of several polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), and polybrominated diphenyl ethers (PBDEs) were measured in precipitation (n = 33) at a suburban site in Izmir, Turkey. Total (dissolved + particle) volume weighted mean (VWM) concentrations for Sigma(16)PAHs, Sigma(18)PCBs, Sigma(17)OCPs, and Sigma 7PBDEs were 785, 19.2, 50.5, and 29.6 ng l(-1), respectively. Low molecular weight (LMW) compounds (acenaphthylene, fluorene, phenanthrene) and congeners (PCB-18, 28, and 31) dominated the PAH and PCB concentrations, respectively. For PBDEs, BDE-209, and for OCPs, chlorpyrifos, a currently used pesticide, were the predominant compounds. Annual Sigma 7PBDEs flux was 18.74 mu g m(-2) year(-1). PBDE fluxes were mainly in dissolved phase for all congeners except BDE-209 which had comparable proportions in both phases. Annual flux for Sigma(16)PAHs was 497.4 mu g m(-2) year(-1); higher molecular weight (MW) PAH fluxes had comparable amounts in both phases while lower MW ones were mostly in dissolved phase. Wet deposition fluxes for Sigma(18)PCBs and Sigma(17)OCPs were 9.40 and 31.94 mu g m(-2) year(-1), respectively, and they were predominantly in dissolved phase. Wet deposition fluxes were compared to previously measured annual dry deposition fluxes at the study site to determine their relative contributions to annual total (dry particle + wet) deposition. Dry deposition was the major removal mechanism for most of the PAHs and PCBs contributing >80 % to total (wet + dry) deposition. However, both processes were comparable for PBDEs. Wet deposition was the predominant process for some OCPs such as alpha-chlordane, gamma-chlordane, and trans-nonachlor while both processes were comparable for chlorpyrifos and heptachlor epoxide.
BibTeX:
@article{Cetin2016,
  author = {Cetin, B. and Odabasi, M. and Bayram, A.},
  title = {Wet deposition of persistent organic pollutants (POPs) in Izmir, Turkey},
  journal = {Environmental Science and Pollution Research},
  year = {2016},
  volume = {23},
  number = {9},
  pages = {9227--9236},
  url = {://WOS:000375412600100},
  doi = {10.1007/s11356-016-6183-6}
}
Cetin B (2016), "Investigation of PAHs, PCBs and PCNs in soils around a Heavily Industrialized Area in Kocaeli, Turkey: Concentrations, distributions, sources and toxicological effects", Science of the Total Environment. Vol. 560, pp. 160-169.
Abstract: Soil is an important environmental mediumreflecting the level and the spatial distribution of air pollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs). Soil concentrations of PCNs measured in the present study were generally higher and PCBs concentrations were considerably higher than those reported in the literature, while PAHs concentrations were comparable. Combustion related PCNs congener ratios to their total concentrations and PAHs diagnostic ratios suggested the substantial contribution of combustion sources and the statistically significant correlation between PCBs and PCNs (r=0.88) indicated that these POPs were emitted from the common sources. Principal Component Analysis was also performed to further assess the possible sources of individual POPs. The results showed the contribution of traffic, petroleumand coal/biomass combustion and iron-steel production. Toxicological effects of POPs in soil were investigated. BaP was used as the marker of carcinogenic PAHs. Seven carcinogenic PAHs concentrations (Sigma(7c)PAH) including BaA, CHR, BbF, BkF, BaP, IcdP and DahA were also used as a parameter to evaluate carcinogenic potency of PAHs. As PCBs and PCNs show dioxin-like toxicities, their toxicological implication were estimated using TCDD equivalence. The results show that the study area faced with severe environmental problems even though the data sets without the complete set of dioxin like PCBs and PCNs would show only a part of the whole toxicological picture. (C) 2016 Elsevier B.V. All rights reserved.
BibTeX:
@article{Cetin2016a,
  author = {Cetin, B.},
  title = {Investigation of PAHs, PCBs and PCNs in soils around a Heavily Industrialized Area in Kocaeli, Turkey: Concentrations, distributions, sources and toxicological effects},
  journal = {Science of the Total Environment},
  year = {2016},
  volume = {560},
  pages = {160--169},
  url = {://WOS:000375137100018},
  doi = {10.1016/j.scitotenv.2016.04.037}
}
Chumakov Y, Aksakal F, Dimoglo A, Ata A and Palomares-Sanchez SA (2016), "First-Principles Study of Thermoelectric Properties of Covalent Organic Frameworks", Journal of Electronic Materials. Vol. 45(7), pp. 3445-3452.
Abstract: Covalent organic frameworks (COFs) are new emerging functional porous materials. Strong covalent bonds result in molecular building blocks that can be arranged in layered two-dimensional (2D) or three-dimensional (3D) periodic networks. However, to the best of our knowledge, there have been no reports on experimental and theoretical studies of thermoelectrical properties of COFs to date. Therefore, density functional theory (DFT) and the Boltzmann transport equation have been applied in this work to calculate the semiclassical transport coefficients for phthalocyanine (Pc)-based NiPc, NiPc-benzothiadiazole (BTDA), and Pc COFs. Owing to the well-ordered stacking of the phthalocyanine units and linkers in these compounds, charge-carrier transport is facilitated in the stacking direction. In all studied compounds, the highly directional character of pi-orbitals provides band-structure engineering and produces a type of low-dimensional hole transport along the stacking direction. All studied compounds are indirect semiconductors. The low-dimensional transport of holes and the localized states in both valence and conduction bands prevent the electron-hole compensation effect in the Seebeck coefficients, correlating with the large Seebeck coefficients of the studied compounds. Insertion of the electron-deficient building block benzothiadiazole in the NiPc-BTDA COF leads to positive Seebeck coefficients along the a-, b-, and c-directions. The relaxation time was estimated in our investigations from DFT band-structure calculations and the experimentally defined mobility, leading to determination of the electrical conductivity and electronic contribution to the thermal conductivity, as well as figure of merit (ZT) estimation. Ni atom provided greater electrical conductivity along the c-direction in comparison with metal-free Pc COF, and NiPc COF showed the highest thermoelectric performance among the studied COFs.
BibTeX:
@article{Chumakov2016,
  author = {Chumakov, Y. and Aksakal, F. and Dimoglo, A. and Ata, A. and Palomares-Sanchez, S. A.},
  title = {First-Principles Study of Thermoelectric Properties of Covalent Organic Frameworks},
  journal = {Journal of Electronic Materials},
  year = {2016},
  volume = {45},
  number = {7},
  pages = {3445--3452},
  url = {://WOS:000377434100027},
  doi = {10.1007/s11664-016-4540-3}
}
Deveci EU, Dizge N, Yatmaz HC and Aytepe Y (2016), "Integrated process of fungal membrane bioreactor and photocatalytic membrane reactor for the treatment of industrial textile wastewater", Biochemical Engineering Journal. Vol. 105, pp. 420-427.
Abstract: In this study, fungal membrane bioreactor (FMBR) and semiconductor photocatalytic membrane reactor (PMR) were used in order to test the efficiency of integrated fungal biodegradation and photocatalytic degradation of textile wastewater from reactive washing processes. It was found that color removal and chemical oxygen demand (COD) reduction efficiencies were 88% and 53% for photocatalytic degradation, respectively. TiO2 and ZnO were tested as semiconductor catalysts in the PMR and TiO2 showed better efficiencies than ZnO for both color and COD removal. However, it was attained that color removal and COD reduction efficiencies were about 56% and 60% for fungal biodegradation using Phatterochaete chrysosporium, respectively. Moreover, integrated system in which photocatalytic degradation was employed as a post-treatment application after fungal biodegradation process achieved high removal efficiencies for color and COD removal as 93% and 99%, respectively. (C) 2015 Elsevier B.V. All rights reserved.
BibTeX:
@article{Deveci2016,
  author = {Deveci, E. U. and Dizge, N. and Yatmaz, H. C. and Aytepe, Y.},
  title = {Integrated process of fungal membrane bioreactor and photocatalytic membrane reactor for the treatment of industrial textile wastewater},
  journal = {Biochemical Engineering Journal},
  year = {2016},
  volume = {105},
  pages = {420--427},
  url = {://WOS:000367776500012},
  doi = {10.1016/j.bej.2015.10.016}
}
Dogan EC, Yasar A, Sen U and Aydiner C (2016), "Water recovery from treated urban wastewater by ultrafiltration and reverse osmosis for landscape irrigation", Urban Water Journal. Vol. 13(6), pp. 553-568.
Abstract: Techno-economic feasibility of water recovery from secondary effluents of an urban wastewater treatment plant (WWTP) for landscape irrigation was investigated considering two distinctive strategies: ultrafiltration (UF)/chlorination and UF/reverse osmosis (RO). Experimental performance evaluations were conducted separately for UF membranes and for different RO trans-membrane pressures. The quality of the effluent recovered by the UF/RO system was in accordance with the national and international guidelines. The produced reuse water was first class quality according to the national guideline for all parameters except sodium adsorption ratio (SAR), which can be eliminated readily by direct addition of KCl into the recovered water. Estimated field-scale costs indicated that UF/RO yielded a total cost of US$12,500,000-13,600,000 with annual operating cost being US$482,000-533,000 at 5-20 bar. The economic estimations guaranteed reimbursement with US$7,600,000-7,400,000 net present value, 0.22-0.39 year payback time, US$0.44-0.49/m(3) treatment cost, and a benefit/cost ratio of 0.57.
BibTeX:
@article{Dogan2016,
  author = {Dogan, E. C. and Yasar, A. and Sen, U. and Aydiner, C.},
  title = {Water recovery from treated urban wastewater by ultrafiltration and reverse osmosis for landscape irrigation},
  journal = {Urban Water Journal},
  year = {2016},
  volume = {13},
  number = {6},
  pages = {553--568},
  url = {://WOS:000377774700001},
  doi = {10.1080/1573062x.2014.992917}
}
Doruk N, Yatmaz HC and Dizge N (2016), "Degradation Efficiency of Textile and Wood Processing Industry Wastewater by Photocatalytic Process Using In Situ Ultrafiltration Membrane", Clean-Soil Air Water. Vol. 44(3), pp. 224-231.
Abstract: The hybrid membrane photocatalytic reactor (MPR) in this study was constructed by submerging a flat polyethersulfone membrane module into a ZnO or TiO2 slurry photocatalytic reactor for raw wastewater treatment. The short and long term MPR performance was investigated for the degradation of textile and wood processing industry wastewater. The different operational parameters such as the catalyst type, catalyst loading, initial wastewater concentration, light type, and semiconductor powder type affecting the performance of the reactor were initially evaluated using a batch system without a membrane module. After the optimization of the operating conditions, the long term studies were performed by the MPR. Nearly 100% color and 30-55% chemical oxygen demand (COD) removal could be reached at a hydraulic retention time of 6 h for both wastewater effluents. Moreover, reverse osmosis experiments were applied on MPR ultrafiltration effluent for further COD removal and up to 88% COD removal efficiency could be obtained. The color and organic matter degradation efficiency showed that the catalyst can be reused effectively in MPR. In this hybrid design, the membrane module served also as a separator which is very advantageous in keeping catalyst powder in suspension during the operation. The results indicated that the effluent water can be used as process water in the industry.
BibTeX:
@article{Doruk2016,
  author = {Doruk, N. and Yatmaz, H. C. and Dizge, N.},
  title = {Degradation Efficiency of Textile and Wood Processing Industry Wastewater by Photocatalytic Process Using In Situ Ultrafiltration Membrane},
  journal = {Clean-Soil Air Water},
  year = {2016},
  volume = {44},
  number = {3},
  pages = {224--231},
  url = {://WOS:000372953200001},
  doi = {10.1002/clen.201400203}
}
Engin GO, Omurlu N and Oncel MS (2016), "Strength and durability characterization of pelletized coal-biomass household briquettes", International Journal of Green Energy. Vol. 13(2), pp. 132-137.
Abstract: Increase in waste sludge disposal is always seen as a problem from the point of production industry. However, it is clear that the reuse and recycle of sewage sludge could be a serious economic input. The most important action should be to determine the sludge characterizations and direct the producers towards appropriate reuse and recycling opportunities. In this study, reuse method was examined to produce coal briquette, which will constitute an example for waste sludge. In order to make use of the waste sludge, five different coal briquette samples were produced by mixing powdered coal and bitumen together with waste sludge, at different ratios. The overall results indicated that the sample named CB3 having 70% powdered coal, 20% waste sludge, and 10% bitumen was found to be the optimum coal briquette among the other samples produced. The proximate analysis of the optimum briquette sample was carried out according to the Turkish standards and regulations and it was found out that the produced briquette coal can have commercial value with a gross calorific value of 30.03 MJ/kg and 7.30% ash content.
BibTeX:
@article{Engin2016,
  author = {Engin, G. O. and Omurlu, N. and Oncel, M. S.},
  title = {Strength and durability characterization of pelletized coal-biomass household briquettes},
  journal = {International Journal of Green Energy},
  year = {2016},
  volume = {13},
  number = {2},
  pages = {132--137},
  url = {://WOS:000373107200002},
  doi = {10.1080/15435075.2014.952418}
}
Eyvaz M (2016), "Treatment of Brewery Wastewater with Electrocoagulation: Improving the Process Performance by Using Alternating Pulse Current", International Journal of Electrochemical Science. Vol. 11(6), pp. 4988-5008.
Abstract: The main aim of this study is to investigate the technical and economic feasibility of electrocoagulation process on the treatment of brewing industry effluents. Effects of current type on process performance were also stated with a batch operated electrocoagulation reactor including four plate electrodes. Two electrode materials, Fe and Al, were separately employed in parallel connection. A low-moderate strength brewery wastewater was selected as wastewater and model electrolyte solution. Direct current power supply with an adjustable time relay by which rectangular wave was produced was combined with sacrificial electrodes. Performance of the electrocoagulation process was analyzed in terms of operating parameters such as, pH, current density, operating time, electrode material, and current type with removal efficiencies, only some of which were presented in figures and others were given in tables due to the numbers of parameters. Both electrode materials exposed similar pollutant removal performances while Al electrode was found cost effective one. However, alternating pulse current was found superior to direct current, namely, it provided higher removal rates in shorter operating times.
BibTeX:
@article{Eyvaz2016,
  author = {Eyvaz, M.},
  title = {Treatment of Brewery Wastewater with Electrocoagulation: Improving the Process Performance by Using Alternating Pulse Current},
  journal = {International Journal of Electrochemical Science},
  year = {2016},
  volume = {11},
  number = {6},
  pages = {4988--5008},
  url = {://WOS:000378559300062},
  doi = {10.20964/2016.06.11}
}
Gorgec AG, Insel G, Yagci N, Dogru M, Erdincler A, Sanin D, Filibeli A, Keskinler B and Cokgor EU (2016), "Comparison of Energy Efficiencies for Advanced Anaerobic Digestion, Incineration, and Gasification Processes in Municipal Sludge Management", Journal of Residuals Science & Technology. Vol. 13(1), pp. 57-64.
Abstract: Municipal sludge has energy content in the range of (9,000-23,000 kJ/kg) depending upon the organic content. This entrapped energy can be transformed into heat and electrical energies by different technologies combining biological and thermal processes. Recently, the combination of advanced digestion and incineration or gasification was found to be advantageous for energy recovery. The energy balance was based upon a full-scale wastewater treatment plant (WWTP) using conventional and advanced treatment configurations. In this respect, the unit electricity production from sludge was calculated to be in the range of 675-1,240 kWhE per tones of dry solids.
BibTeX:
@article{Gorgec2016,
  author = {Gorgec, A. G. and Insel, G. and Yagci, N. and Dogru, M. and Erdincler, A. and Sanin, D. and Filibeli, A. and Keskinler, B. and Cokgor, E. U.},
  title = {Comparison of Energy Efficiencies for Advanced Anaerobic Digestion, Incineration, and Gasification Processes in Municipal Sludge Management},
  journal = {Journal of Residuals Science & Technology},
  year = {2016},
  volume = {13},
  number = {1},
  pages = {57--64},
  url = {://WOS:000369728600008}
}
Inan H, Turkay O and Akkiris C (2016), "Microwave and microwave-chemical pretreatment application for agricultural waste", Desalination and Water Treatment. Vol. 57(6), pp. 2590-2596.
Abstract: This study aimed to investigate the effect of microwave (MW) and microwave-chemical (MWC) pretreatment on barley straw and to identify the acidic, basic, or oxidative chemicals that provide the highest sugar conversion for subsequent enzymatic hydrolysis. The MW and MWC processes were applied as a pretreatment step before fermentation. MW radiation at 200 and 300W and MW radiation plus a chemical (H2SO4 or NaOH or H2O2) as catalyst were applied, and total sugar, total phenol, and Klason and acid-soluble lignin were measured. Although the MWC pretreatment produced a higher total sugar concentration than the MW pretreatment, the addition of an NaOH solution produced the best results in terms of all parameters. Fourier transform infrared analysis was also performed to observe the deterioration of molecular structures after the application of MW and MWC.
BibTeX:
@article{Inan2016,
  author = {Inan, H. and Turkay, O. and Akkiris, C.},
  title = {Microwave and microwave-chemical pretreatment application for agricultural waste},
  journal = {Desalination and Water Treatment},
  year = {2016},
  volume = {57},
  number = {6},
  pages = {2590--2596},
  url = {://WOS:000367837600025},
  doi = {10.1080/19443994.2015.1069217}
}
Kobya M, Gengec E and Demirbas E (2016), "Operating parameters and costs assessments of a real dyehouse wastewater effluent treated by a continuous electrocoagulation process", Chemical Engineering and Processing. Vol. 101, pp. 87-100.
Abstract: Treatment of a real dyehouse wastewater was studied with continuous flow electrocoagulation (CEC) process. Removal efficiencies of COD, TOC and turbidity were obtained as 85%, 76% and 95% for Fe electrode and 77%, 72% and 95% for Al electrode at current density of 65 Al/m(2), inlet flow rate of 0.010 L/min, operating time of 80 min (hydraulic retention time of 350 min), and current density of 65 A/m(2) (the optimum operating conditions). The decrease in the inlet flow rate (0.20-0.010 L/min) led to an increase in removal efficiencies of COD (58-85% for Fe, 55-77% for Al), TOC (51-76% for Fe and 46-72% for Al) and turbidity (70-95% for Fe and 72-95% for Al). Operating costs for Fe and Al electrodes at the optimum operating conditions were calculated as 1.562 $/m(3) or 7.282 $/kg COD for Fe electrode and 1.851 $/m(3) or 14.257 $/kg COD for Al electrode. The results presented in this study revealed that the CEC process can be effectively used for the removals of color, COD, TOC and turbidity from textile wastewater. (C) 2015 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kobya2016,
  author = {Kobya, M. and Gengec, E. and Demirbas, E.},
  title = {Operating parameters and costs assessments of a real dyehouse wastewater effluent treated by a continuous electrocoagulation process},
  journal = {Chemical Engineering and Processing},
  year = {2016},
  volume = {101},
  pages = {87--100},
  url = {://WOS:000371842100010},
  doi = {10.1016/j.cep.2015.11.012}
}
Mansouri A, Rihani R, Laoufi AN and Ozkan M (2016), "Production of bioethanol from a mixture of agricultural feedstocks: Biofuels characterization", Fuel. Vol. 185, pp. 612-621.
Abstract: Bioethanol production from a mixture of agricultural feedstock was carried out in a batch fermenter. To study the effect of optimal mixture ratio of fruit juices (100% dates; 70% dates + 30% grapes, 50% dates + 50% grapes, 30% dates + 70% grapes, 100% grapes) on ethanol yield (g ethanol/g sugar), different parameters have been monitored such as ethanol yield, total sugar, ammoniacal nitrogen, pH. It was found that the mixture of Mech Degla dates and grapes juices has the higher bioethanol concentration than that obtained from a single juice from one kind of fruit. Higher bioethanol production 155.5 g/L at 72 h was obtained when 30% dates juice was blended with 70% grapes juice. In such case, the higher initial sugar concentration is close to 228.34 g/L, and the pH droped from 4.5 to 3.87. The Luedeking-Piret model was used to describe the bioethanol production. A good agreement was found between simulated and experimental data. The influence of some physical properties on the addition of ethanol to lead-free gasoline has been studied. It was found that the addition of 5% of ethanol, to lead-free gasoline raises the RON to around 96.4, that can improve its octane number by 2 points. (C) 2016 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Mansouri2016,
  author = {Mansouri, A. and Rihani, R. and Laoufi, A. N. and Ozkan, M.},
  title = {Production of bioethanol from a mixture of agricultural feedstocks: Biofuels characterization},
  journal = {Fuel},
  year = {2016},
  volume = {185},
  pages = {612--621},
  url = {://WOS:000382248700063},
  doi = {10.1016/j.fuel.2016.08.008}
}
Sakar H, Canbolat CB, Karagunduz A and Keskinler B (2016), "Sulfate removal from nanofiltration concentrate of alkaloid wastewater by electrodialysis", Desalination and Water Treatment. Vol. 57(44), pp. 21003-21014.
Abstract: Treatment of alkaloid wastewater is a challenging task because of its complex mixture of contaminants with high chemical oxygen demand and sulfate concentrations. The aim of this study was to investigate the removal of sulfate from nanofitration (NF) concentrate of alkaloid wastewater by electrodialysis (ED). The effectiveness of ED process was evaluated using synthetic sodium sulfate solutions at three different concentrations (20, 30, and 40g/L). The removal efficiencies ranged from 95 to 98% at all applied voltages (5-20V). Energy consumption for 95% sulfate removal was linearly increasing with applied voltage. The influences of diluate and concentrate flow rates on sulfate removal were investigated at 20, 30, and 40 L/h. At least 95% of deionization efficiencies were achieved at all flow rates. The performance of three different NF membranes (NF270, NF90, and NF245) was investigated in order to remove sulfate from biologically treated alkaloid wastewater. Ninety-nine percent of sulfate retained in membrane concentrate in NF90 and NF245 membranes. Finally, the sulfate removal efficiencies from NF concentrate were determined by ED process. Up to 98% of deionization efficiencies were achieved. However, both ED time to teach 95% efficiency and the energy consumptions for the same degree of treatment were much greater that those obtained using synthetic wastewater.
BibTeX:
@article{Sakar2016,
  author = {Sakar, H. and Canbolat, C. B. and Karagunduz, A. and Keskinler, B.},
  title = {Sulfate removal from nanofiltration concentrate of alkaloid wastewater by electrodialysis},
  journal = {Desalination and Water Treatment},
  year = {2016},
  volume = {57},
  number = {44},
  pages = {21003--21014},
  url = {://WOS:000382975100034},
  doi = {10.1080/19443994.2015.1125803}
}
Sevimoglu O and Rogge WF (2016), "Seasonal size-segregated PM10 and PAH concentrations in a rural area of sugarcane agriculture versus a coastal urban area in Southeastern Florida, USA", Particuology. Vol. 28, pp. 52-59.
Abstract: Airborne particulate matter (PM) is of health and environmental concern not only in highly urbanized areas, but also in rural areas that are used for intensive agricultural purposes. In this study, PM size-segregated samples were collected simultaneously for 12 months in a small town (Belle Glade, Florida), which is the center of a vast sugarcane growing area and at Delray Beach, a coastal city in Palm Beach County, Florida. During the winter sampling period, when sugarcane foliage is burned just before harvesting to reduce the amount of plant matter to be handled, PM10 levels were 50% or higher than otherwise measured, indicating that sugarcane harvesting and processing is a major local source for PM10. For the rest of the year, PM10 levels at both sites are similar, suggesting that ambient PM levels at both sites are impacted by the major urban centers in Southern Florida. During late July and early August, the PM10 levels at both sites were substantially elevated and revealed the typical red-brownish color of Saharan dust. This has been reported to occur frequently with suitable meteorological conditions over the Atlantic Ocean coupled with a Sahara dust storm event. During the sugarcane harvesting season at Belle Glade, the concentrations of PAHs associated with PM10 were up to 15 times higher than those measured during the summer growing season, indicating a substantially higher exposure of the rural population to these often mutagenic and carcinogenic compounds. (C) 2016 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.
BibTeX:
@article{Sevimoglu2016,
  author = {Sevimoglu, O. and Rogge, W. F.},
  title = {Seasonal size-segregated PM10 and PAH concentrations in a rural area of sugarcane agriculture versus a coastal urban area in Southeastern Florida, USA},
  journal = {Particuology},
  year = {2016},
  volume = {28},
  pages = {52--59},
  url = {://WOS:000382351600007},
  doi = {10.1016/j.partic.2015.09.013}
}
Soydemir G, Keris-Sen UD, Sen U and Gurol MD (2016), "Biodiesel production potential of mixed microalgal culture grown in domestic wastewater", Bioprocess and Biosystems Engineering. Vol. 39(1), pp. 45-51.
Abstract: In this study, a mixed microalgal culture grown in secondarily treated domestic wastewater effluent was investigated for biodiesel production using in situ transesterification method with conventional heating. The total lipid content of the mixed culture was found as 26.2 % +/- A 0.6 by weight of dry biomass, and 74 % of the lipids were contributed by total glycerides. In situ transesterification with conventional heating process under acidic conditions produced higher biodiesel yield with chloroform as the co-solvent (82.1 % +/- A 3.9) compared to hexane (55.3 % +/- A 3.9) under the same reaction conditions. The gas chromatography analysis showed that FAME composition was mainly composed of palmitic, palmitoleic, stearic, oleic, linoleic and linolenic acid methyl esters., and thus the mixed microalgal culture fed by domestic wastewaters has had comparable biodiesel conversion yields and FAME composition to mono-culture and pure cultures fed by synthetic culture media. Hence, this study showed that secondarily treated domestic wastewater could potentially be a suitable and sustainable medium for microalgae grown to be used as biodiesel feedstock.
BibTeX:
@article{Soydemir2016,
  author = {Soydemir, G. and Keris-Sen, U. D. and Sen, U. and Gurol, M. D.},
  title = {Biodiesel production potential of mixed microalgal culture grown in domestic wastewater},
  journal = {Bioprocess and Biosystems Engineering},
  year = {2016},
  volume = {39},
  number = {1},
  pages = {45--51},
  url = {://WOS:000367607200003},
  doi = {10.1007/s00449-015-1487-3}
}
Turkay O, Barisci S and Dimoglo A (2016), "Kinetics and mechanism of methylene blue removal by electrosynthesized ferrate(VI)", Separation Science and Technology. Vol. 51(11), pp. 1924-1931.
Abstract: The oxidation of methylene blue (MB) by electrosynthesized ferrate(VI) in a semi-batch reactor is investigated. The effects of pH, Fe(VI) dose and initial MB concentration on the efficiency of the degradation process were studied. The original pH of MB solution was found more effective on the degradation and colour removal as 96.82% MB removal and 40.36% colour removal were gained. Initial MB solution and Fe(VI) dose affected the removal efficiencies. Degradation of MB by Fe(VI) was the second-order reaction kinetics. The density functional theory (DFT) analysis confirmed that density is intended mostly on the phenyl rings and least of all on the bonding orbitals of the middle heterocycle of MB.
BibTeX:
@article{Turkay2016,
  author = {Turkay, O. and Barisci, S. and Dimoglo, A.},
  title = {Kinetics and mechanism of methylene blue removal by electrosynthesized ferrate(VI)},
  journal = {Separation Science and Technology},
  year = {2016},
  volume = {51},
  number = {11},
  pages = {1924--1931},
  url = {://WOS:000381286400015},
  doi = {10.1080/01496395.2016.1182189}
}
Turkay O, Barisci S and Dimoglo A (2016), "Assessment of parameters influencing the electro activated, water character and explanation of process mechanism", Process Safety and Environmental Protection. Vol. 99, pp. 129-136.
Abstract: The physicochemical properties of electro activated water (EAW) are highly affected by process conditions. In this context, the effects of parameters such as brine concentration, electrolysis time and current for EAW generation have been investigated using Response Surface Methodology (RSM). The predictive model for each response had high accuracy relative to R-2 values, namely, 0.85 for the oxidation reduction potential (ORP) and 0.94 for the free chlorine concentration (FCC). According to results, the brine concentration was the most significant factor that affected EAW character. Moreover, electrolysis time and brine concentration have synergetic effect on FCC. The mechanism of the EAW production was evaluated through the cyclic voltammogram (CV) of different brine concentrations on the graphite electrode. With the concentration increased anodic and cathodic peaks could be observed notably. Possible reaction pathways were evaluated on the cathode and anode sides. The formation of Cl-2, O-2, H-2, Cl-, OH-, H+ were determined by CV measurements. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
BibTeX:
@article{Turkay2016a,
  author = {Turkay, O. and Barisci, S. and Dimoglo, A.},
  title = {Assessment of parameters influencing the electro activated, water character and explanation of process mechanism},
  journal = {Process Safety and Environmental Protection},
  year = {2016},
  volume = {99},
  pages = {129--136},
  url = {://WOS:000370104700013},
  doi = {10.1016/j.psep.2015.10.020}
}
Yamaner C, Ayvaz M, Konak R, Tan N, Kosoglu I and Dimoglo A (2016), "EFFICACY OF NEUTRALISED ELECTROLYSED WATER AND MILD HEAT AGAINST FOODBORNE PATHOGENS ISOLATED FROM FICUS CARICA", Italian Journal of Food Science. Vol. 28(2), pp. 208-220.
Abstract: Problems with microorganism toxins in dried fig exports are becoming very important. Chlorine-based sanitizers are effective way of controlling microorganisms, but on the other hand their reaction with natural organic and inorganic matter may potentially form carcinogenic products. Therefore, different sanitizers for the disinfection of food and food contact surfaces are required as an alternative to chlorine-based sanitizers. Some earlier studies revealed that neutralised electrolysed water (NEW) may be a potential substitute for cleaning and sanitizing agents in packaged products. In order to make a contribution to solve toxins problems, the antibacterial and antifungal effect of neutralised electrolysed water (NEW) on the foodborne pathogens were evaluated in this study. Spores of Aspergillus flavus and Penicillium expansum were isolated from the surface of fig fruits. Escherichia coli and Bacillus cereus known to occur on the surface of figs were also evaluated. Vegetative cells and spores of bacterium and fungi were exposed to five different concentrations of NEW (100, 75, 25, 5 and 1%) at three different temperatures (22, 50 and 70 degrees C) for 1, 3 and 5 min. According to the results, at 22 degrees C, 1% neutralised electrolysed water exposure for 1 min effectively decreased the number of vegetative cells of E. coli and B. cereus by approximately 8.5 log cfu/ml and 6.3 log cfu/ml, respectively. At 50 degrees C, 5% neutralised electrolysed water exposure for 1 min significantly reduced the A. flavus and P. expansum spore numbers by 5.54 log cfu/ml and 7 log cfu/ml, respectively. With the effect of mild temperature (22-50 degrees C), low chlorine neutralised electrolysed water (9.22 mg/l - 33.85 mg/l available chlorine concentrations) showed a strong antibacterial and antifungal activity against foodborne pathogens. As a conclusion, neutralised electrolysed water can be used widely as a sanitizer in fig enterprises, instead of high cost chlorine based disinfectants.
BibTeX:
@article{Yamaner2016,
  author = {Yamaner, C. and Ayvaz, M. and Konak, R. and Tan, N. and Kosoglu, I. and Dimoglo, A.},
  title = {EFFICACY OF NEUTRALISED ELECTROLYSED WATER AND MILD HEAT AGAINST FOODBORNE PATHOGENS ISOLATED FROM FICUS CARICA},
  journal = {Italian Journal of Food Science},
  year = {2016},
  volume = {28},
  number = {2},
  pages = {208--220},
  url = {://WOS:000377012900004}
}
Aksakal F, Shvets N and Dimoglo A (2015), "The study of dual COX-2/5-LOX inhibitors by using electronic-topological approach based on data on the ligand-receptor interactions", Journal of Molecular Graphics & Modelling. Vol. 60, pp. 79-88.
Abstract: Structural and electronic factors influencing selective inhibition of cyclooxygenase-2 and 5-lipoxygenase (COX-2/5-LOX) were studied by using Electronic-Topological Method combined with Neural Networks (ETM-NN), molecular docking, and Density Functional Theory (DFT) in a large set of molecules. The results of the ETM-NN calculations allowed for the selection of pharmacophoric molecular fragments, which could be taken as a basis for a system capable of predicting the COX-2/5-LOX inhibitory activity. For the more effective extraction of the pharmacophoric molecular fragments, docking of molecules into the active sites of the two enzymes was carried out to get data on the ligand-receptor interaction. To make an assessment of these interactions, stabilization energies were calculated by using Natural Bond Orbital (NBO) analysis. Docking and data on the electronic structures of active sites of enzymes helped to reveal effectively the peculiarities of the ligand-receptor binding. The system for the selective COX-2/5-LOX inhibitory activity prediction that has been developed as the result of the ETM-NN study recognized correctly 93% of compounds as highly active ones. Thus, this system can be successfully used for carrying out computer screening and synthesis of potent inhibitors of COX-2/5-LOX with diverse molecular skeletons. (C) 2015 Elsevier Inc. All rights reserved.
BibTeX:
@article{Aksakal2015,
  author = {Aksakal, F. and Shvets, N. and Dimoglo, A.},
  title = {The study of dual COX-2/5-LOX inhibitors by using electronic-topological approach based on data on the ligand-receptor interactions},
  journal = {Journal of Molecular Graphics & Modelling},
  year = {2015},
  volume = {60},
  pages = {79--88},
  url = {://WOS:000359174900008},
  doi = {10.1016/j.jmgm.2015.06.006}
}
Aydiner C (2015), "A model-based analysis of water transport dynamics and fouling behaviors of osmotic membrane", Chemical Engineering Journal. Vol. 266, pp. 289-298.
Abstract: Water transport performance of forward osmosis (FO) has a crucial significance for successful implementations of the process in water and wastewater reclamation and seawater desalination. But, ascertainment of membrane fouling dynamics associated with simultaneous solute and water transfer still remains as one of the main research subjects for FO's technological development. This study provides a deep insight to reveal the relations between water transport and membrane fouling propensities in FO by which model-based analysis was performed based on a novel osmotic resistance-in-series model developed for normal and reverse membrane orientations. Model results indicated that for the membrane operated with real seawater, osmotic water flux was mainly dependent on the active layer resistance regardless of orientation mode and osmosis time. Interfacial layer from effective draw interface by active layer/draw bulk interface, [d(w) - m(a)/d(b)] seemed to be the main performance-limiting domain in which, as interfacial fouling increased, membrane permeated less water to draw. Predominant mechanisms were designated as homogeneous fouling of equivalent solute distributions and heterogeneous fouling of non-uniform nano-exclusion zones in normal and reverse modes, respectively. More interestingly, it was comprehended for reverse mode that the nature of nano-exclusion zones at the interface turned to a feature of uniform solute distributions at the interface m(a)/d(b). Very good agreements were found between experimental fluxes and theoretical results based on dimensional and dimensionless structural parameter and total resistances. After all, distinctive fouling behaviors clarified upon the adopted dynamics of transport were strongly verified by consistencies of high accuracy in the model estimations. (C) 2015 Elsevier B.V. All rights reserved.
BibTeX:
@article{Aydiner2015,
  author = {Aydiner, C.},
  title = {A model-based analysis of water transport dynamics and fouling behaviors of osmotic membrane},
  journal = {Chemical Engineering Journal},
  year = {2015},
  volume = {266},
  pages = {289--298},
  url = {://WOS:000350931600033},
  doi = {10.1016/j.cej.2014.12.098}
}
Barisci S, Ulu F, Sillanpaa M and Dimoglo A (2015), "Evaluation of flurbiprofen removal from aqueous solution by electrosynthesized ferrate(VI) ion and electrocoagulation process", Chemical Engineering Journal. Vol. 262, pp. 1218-1225.
Abstract: The removal of flurbiprofen (FLU) by electrosynthesized ferrate(VI) ion and electrocoagulation (EC) process was investigated. The degradation of FLU by ferrate(VI) was affected by pH, applied ferrate(VI) dose and initial drug concentration. Complete removal of FLU was achieved at pH 4 and applied ferrate(VI) dose was 1/1 in volume ratio for its initial concentration of 1 mg/L. Removal decreased with increasing pH. Increasing the ferrate(VI) dose increased the efficiency, but there was no significant difference between 3/1 and 1/1 (v/v) ferrate(VI) doses for FLU removal. The effect of current density and pH for the removal of FLU by EC process were investigated. The optimum conditions were current density of 2.5 mA/cm(2) and the solution pH of 6.5. Basic condition (pH 9) showed poor removal efficiency by EC process. Equilibrium concentration was reached within 20 min. TOC removal trends were also investigated for both process. While oxidation was the main mechanism for the removal of FLU by ferrate(VI), charge neutralization was the main removal mechanism by EC process. (C) 2014 Elsevier B.V. All rights reserved.
BibTeX:
@article{Barisci2015,
  author = {Barisci, S. and Ulu, F. and Sillanpaa, M. and Dimoglo, A.},
  title = {Evaluation of flurbiprofen removal from aqueous solution by electrosynthesized ferrate(VI) ion and electrocoagulation process},
  journal = {Chemical Engineering Journal},
  year = {2015},
  volume = {262},
  pages = {1218--1225},
  url = {://WOS:000347577700134},
  doi = {10.1016/j.cej.2014.10.083}
}
Barlik N, Keskinler B, Kocakerim MM and Akay G (2015), "Surface modification of monolithic PolyHIPE Polymers for anionic functionality and their ion exchange behavior", Journal of Applied Polymer Science. Vol. 132(29)
Abstract: Monolithic PolyHIPE Polymer (PHP), being a highly porous, low density, open cellular material was produced by polymerization of a high internal phase emulsion (HIPE) in which the polymerizable continuous phase consisted of monomers, styrene (STY), and divinyl benzene (DVB). The inner dispersed phase (90 vol %) was an aqueous solution containing 0.4 wt % potassium persulphate as initiator. The resulting porous structure had 12% crosslinking density. Surface chemistry of the monoliths was modified by chloromethylation and amination to impart anionic functionality. Surface modified monoliths had ion exchange capacity of 3.01 meq/g, and had the ability to uptake water about 10 times of its mass. It was used Cr (VI) ion removal from aqueous solution. The experimental results investigated for both the Langmuir and the Dubinin-Radushkevich adsorption models. The maximum Cr (VI) adsorptions are 126.6 mg Cr (VI)/g and 129.3 mg Cr (VI)/g, respectively. The mean free energy E of adsorption is 11.18 kJ/mol according to the Dubinin-Radushkevich adsorption model, indicating that the adsorption occurs through a chemical ion-exchange process and it is not diffusion limited. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42286.
BibTeX:
@article{Barlik2015,
  author = {Barlik, N. and Keskinler, B. and Kocakerim, M. M. and Akay, G.},
  title = {Surface modification of monolithic PolyHIPE Polymers for anionic functionality and their ion exchange behavior},
  journal = {Journal of Applied Polymer Science},
  year = {2015},
  volume = {132},
  number = {29},
  url = {://WOS:000353976700020},
  doi = {10.1002/app.42286}
}
Bououdina M, Oral AY and Oral ZBB (2015), "Preface to the special section on "Hydrogen energy efficiency and advanced materials for hydrogen production, storage and fuel cells"", International Journal of Hydrogen Energy. Vol. 40(40), pp. 14020-14020.
BibTeX:
@article{Bououdina2015,
  author = {Bououdina, M. and Oral, A. Y. and Oral, Z. B. B.},
  title = {Preface to the special section on "Hydrogen energy efficiency and advanced materials for hydrogen production, storage and fuel cells"},
  journal = {International Journal of Hydrogen Energy},
  year = {2015},
  volume = {40},
  number = {40},
  pages = {14020--14020},
  url = {://WOS:000363080200016},
  doi = {10.1016/j.ijhydene.2015.09.031}
}
Buhan SD, Bektas N, Kocer MAT, Dogan HM, Buhan E and Polat F (2015), "TROPHIC STATUS AND THREATS IN ZINAV LAKE (TOKAT/TURKEY)", Fresenius Environmental Bulletin. Vol. 24(1A), pp. 203-207.
Abstract: This study was conducted to determine water quality and trophic state of Zinav Lake, which is located in the Central Black Sea Region of Turkey. Temperature, dissolved oxygen, pH, electrical conductivity, total suspended solids, Secchi disc transparency, ammonia, nitrite, nitrate, total nitrogen, soluble reactive phosphorus, total phosphorus and chlorophyll a were monitored in water column from January 2012 to June 2013. The study showed that Zinav Lake was a dimictic lake, which circulated in spring and fall, and thermally stratified in summer. Hypo-limnetic oxygen deficit and metalimnetic oxygen minima were the cases. Vertical distribution of dissolved oxygen and pH and ammonia accumulation in hypolimnion represented eutrophic/hypereutrophic conditions. The values and ratios of nutrients and chlorophyll a and Secchi disc transparency clearly classified Zinav Lake as eutrophic/hypereutrophic. Allochthonous loadings of organic matter and nutrients from the catchment and the changes in hydrological cycle by a power plant seem to be the most threatening factors controlling the water quality and trophic state in Zinav Lake.
BibTeX:
@article{Buhan2015,
  author = {Buhan, S. D. and Bektas, N. and Kocer, M. A. T. and Dogan, H. M. and Buhan, E. and Polat, F.},
  title = {TROPHIC STATUS AND THREATS IN ZINAV LAKE (TOKAT/TURKEY)},
  journal = {Fresenius Environmental Bulletin},
  year = {2015},
  volume = {24},
  number = {1A},
  pages = {203--207},
  url = {://WOS:000351332400007}
}
Dogan HM, Kilic OM, Yilmaz DS, Buhan E, Polat F and Buhan SD (2015), "INTEGRATION OF GIS AND REMOTE SENSING WITH THE USLE MODEL IN THE ASSESSMENT OF ANNUAL SOIL LOSS AND SEDIMENT INPUT OF ZINAV LAKE BASIN IN TURKEY", Fresenius Environmental Bulletin. Vol. 24(1A), pp. 172-179.
Abstract: The effects of annual soil loss on Zinav Lake Basin located in Tokat Province of Turkey were researched. The annual soil loss of the study area was modelled and mapped by using the Universal Soil Loss Equation (USLE), Geographic Information Systems (GIS) and remote sensing (RS). Employing the USLE model, precipitation (R), the degree of slope and length of slope (L and S), soil erodibility (K), vegetation cover-land use (C), and soil conservation (P) factors were separately calculated and transformed to raster maps in GIS environment. Then, all produced factor map layers were multiplied each other to develop an annual soil loss raster map. Annual sediment input was calculated by utilizing Roehl sediment delivery ratio and developed annual soil loss raster map. The mean annual soil loss of the study area was determined as 0.037 t.ha(-1) year(-1). Erosion risk classes of the study area were determined according to European Environment Information and Observation Network for Soil (EIO-NET-SOIL) Erosion Map, and summarized as five classes including the 0-0.5, 0.5-1.0, 1.0-2.0, 2.0-5.0 and 5.0-7.1 tha(-1)year(-1) I intervals. Sediment delivery ratio and mean annual sediment input were determined as 44.67% and 0.181 tha(-1)year(-1), respectively.
BibTeX:
@article{Dogan2015,
  author = {Dogan, H. M. and Kilic, O. M. and Yilmaz, D. S. and Buhan, E. and Polat, F. and Buhan, S. D.},
  title = {INTEGRATION OF GIS AND REMOTE SENSING WITH THE USLE MODEL IN THE ASSESSMENT OF ANNUAL SOIL LOSS AND SEDIMENT INPUT OF ZINAV LAKE BASIN IN TURKEY},
  journal = {Fresenius Environmental Bulletin},
  year = {2015},
  volume = {24},
  number = {1A},
  pages = {172--179},
  url = {://WOS:000351332400003}
}
Ergon-Can T, Erhan E and Algur OF (2015), "Poly(glycidyl methacrylate-co-3-thienylmethylmethacrylate) as an immobilization matrix for microbial glycerol biosensing based on Gluconobacter oxydans", Materials Science & Engineering C-Materials for Biological Applications. Vol. 56, pp. 432-437.
Abstract: A commercial strain of Gluconobacter oxydans together with a new co-polymer Poly(glycidyl methacrylate-co-3thienylmethylmethacrylate) (Poly(GMA-co-MTM)), which provides effective immobilization in the continuous flow system, was used in the sensor design. By taking the advantages of the nano-technology, carbon nanotubes (CNTs) were also added to the cell film and the sensitivity of the sensor was increased about 15 times. During the glycerol analysis in the continuous system, it was shown that composite film was not removed from the electrode surface and film elements were not washed out from the system. Glycerol analyses were performed by using batch loaded continuously flow cell at different flow rates of 1, 2, 4, and 6 mL/min. The linear range was found as 2-100 mM with the detection limit (LOD) of 0.057 mM according to S/N = 3. The calibration graphs were obtained for Poly(GMA-co-MTM)/G. oxydans and Poly(GMA-co-MTM)/CNT/G. oxydans biofilm electrodes in FIA mode, and sensitivities were found to be 1.50 nA/mM and 19.13 nA/mM, respectively. In this study, Poly(GMA-co-MTM) was used for the first time as a microbial matrix and was shown to be an effective immobilizatipn agent (C) 2015 Elsevier B.V. All rights reserved.
BibTeX:
@article{Ergon-Can2015,
  author = {Ergon-Can, T. and Erhan, E. and Algur, O. F.},
  title = {Poly(glycidyl methacrylate-co-3-thienylmethylmethacrylate) as an immobilization matrix for microbial glycerol biosensing based on Gluconobacter oxydans},
  journal = {Materials Science & Engineering C-Materials for Biological Applications},
  year = {2015},
  volume = {56},
  pages = {432--437},
  url = {://WOS:000359873900053},
  doi = {10.1016/j.msec.2015.07.006}
}
Gulcan HO, Unlu S, Dimoglo A, Sahin Y, Esiringu I, Ercetin T, Oz D and Sahin MF (2015), "Marginally Designed New Profen Analogues Have the Potential to Inhibit Cyclooxygenase Enzymes", Archiv Der Pharmazie. Vol. 348(1), pp. 55-61.
Abstract: The current structure-activity relationship of profens (i.e., 2-arylpropionic acid derivatives, a class of non-steroidal anti-inflammatory drugs) discusses the importance of alpha-monomethyl substitution on these compounds, since the activities obtained through their corresponding arylacetic acid derivatives (i.e., alpha-demethylated derivatives) or alpha,alpha-dimethyl-substituted compounds are less than what is observed for the parent profens. Unfortunately, this implies a generalization in structure-activity relationships of profens in such a way that a mono-(non-methyl)alkyl group or dialkyl substituent replaced at the alpha-position of a profen analogue results in abolished activity. Therefore, within this study, we aimed to question this generalization employing ibuprofen, flurbiprofen, and naproxen as model compounds. A series of alpha-(non-methyl) alkyl-substituted ibuprofen and flurbiprofen analogues as well as alpha, alpha-dialkyl-substituted ibuprofen, flurbiprofen, and naproxen derivatives were synthesized and screened for their potential to inhibit cyclooxygenase enzymes. In addition, since profens have negligible potential to inhibit lipoxygenase enzymes, the effect of such derivatization was also questioned in lipoxygenase inhibition assays. The findings only partially agreed with the current structure-activity approach of profens and the activity results of some compounds were found as beyond ordinary.
BibTeX:
@article{Gulcan2015,
  author = {Gulcan, H. O. and Unlu, S. and Dimoglo, A. and Sahin, Y. and Esiringu, I. and Ercetin, T. and Oz, D. and Sahin, M. F.},
  title = {Marginally Designed New Profen Analogues Have the Potential to Inhibit Cyclooxygenase Enzymes},
  journal = {Archiv Der Pharmazie},
  year = {2015},
  volume = {348},
  number = {1},
  pages = {55--61},
  url = {://WOS:000347710600007},
  doi = {10.1002/ardp.201400366}
}
Guler E, Onkal GO, Celen M and Erkan HS (2015), "COST ANALYSIS OF SEAWATER DESALINATION USING AN INTEGRATED REVERSE OSMOSIS SYSTEM ON A CRUISE SHIP", Global Nest Journal. Vol. 17(2), pp. 389-396.
Abstract: The best method to treat seawater is known to be the use of reverse osmosis (RO) systems. The cost factor becomes the most important issue when using RO systems. Although quite costly, RO systems are essential systems for ships. As known very well, water is a critical resource on ships, especially the ones serving quite a large number of passengers. In this study, therefore, RO system capability under different conditions together with cost analysis was examined on a relatively small cruise ship. The system used had a daily water treatment capacity of 30 m(3). The RO system was composed of a sand filter, a cartridge filter, four pieces of membrane filter modules and a mineral filter. During the study, samples from the Black Sea, the Aegean Sea and the Mediterranean Sea, which have different physical and chemical properties, were examined from the quality point of view. A comprehensive cost analysis was also performed in order to determine the feasibility of the system for the production of potable water for a cruise ship.
BibTeX:
@article{Guler2015,
  author = {Guler, E. and Onkal, G. O. and Celen, M. and Erkan, H. S.},
  title = {COST ANALYSIS OF SEAWATER DESALINATION USING AN INTEGRATED REVERSE OSMOSIS SYSTEM ON A CRUISE SHIP},
  journal = {Global Nest Journal},
  year = {2015},
  volume = {17},
  number = {2},
  pages = {389--396},
  url = {://WOS:000366543000016}
}
Kandemirli F, Vurdu CD, Basaran MA, Sayiner HS, Shvets N, Dimoglo A, Kovalish V and Polat T (2015), "Electronic-Topological and Neural Network Approaches to the Structure-Antimycobacterial Activity Relationships Study on Hydrazones Derivatives", Medicinal Chemistry. Vol. 11(1), pp. 77-85.
Abstract: That the implementation of Electronic-Topological Method and a variant of Feed Forward Neural Network (FFNN) called as the Associative Neural Network are applied to the compounds of Hydrazones derivatives have been employed in order to construct model which can be used in the prediction of antituberculosis activity. The supervised learning has been performed using (ASNN) and categorized correctly 84.4% of them, namely, 38 out of 45. Ph1 pharmacophore and Ph2 pharmacophore consisting of 6 and 7 atoms, respectively were found. Anti-pharmacophore features so-called "break of activity" have also been revealed, which means that APh1 is found in 22 inactive molecules. Statistical analyses have been carried out by using the descriptors, such as E-HOMO, E-LUMO, Delta E, hardness, softness, chemical potential, electrophilicity index, exact polarizibility, total of electronic and zero point energies, dipole moment as independent variables in order to account for the dependent variable called inhibition efficiency. Observing several complexities, namely, linearity, nonlinearity and multi-co linearity at the same time leads data to be modeled using two different techniques called multiple regression and Artificial Neural Networks (ANNs) after computing correlations among descriptors in order to compute QSAR. Computations resulting in determining some compounds with relatively high values of inhibition are presented.
BibTeX:
@article{Kandemirli2015,
  author = {Kandemirli, F. and Vurdu, C. D. and Basaran, M. A. and Sayiner, H. S. and Shvets, N. and Dimoglo, A. and Kovalish, V. and Polat, T.},
  title = {Electronic-Topological and Neural Network Approaches to the Structure-Antimycobacterial Activity Relationships Study on Hydrazones Derivatives},
  journal = {Medicinal Chemistry},
  year = {2015},
  volume = {11},
  number = {1},
  pages = {77--85},
  url = {://WOS:000349330100010}
}
Karagunduz A, Young MH and Pennell KD (2015), "Influence of surfactants on unsaturated water flow and solute transport", Water Resources Research. Vol. 51(4), pp. 1977-1988.
Abstract: Surfactants can reduce soil water retention by changing the surface tension of water and the contact angle between the liquid and solid phases. As a result, water flow and solute transport in unsaturated soil may be altered in the presence of surfactants. In this study, the effects of a representative nonionic surfactant, Triton X-100, on coupled water flow and nonreactive solute transport during unsaturated flow conditions were evaluated. Batch reactor experiments were conducted to measure the surfactant sorption characteristics, while unsaturated transport experiments were performed in columns packed with 40-270 mesh Ottawa sand at five initial water contents. Following the introduction of surfactant solution, the rate of water percolation through the sand increased; however, this period of rapid water drainage was followed by decreased water percolation due to the reduction in soil water content and the corresponding decrease in unsaturated hydraulic conductivity behind the surfactant front. The observed changes in water percolation occurred sequentially, and resulted in faster nonreactive solute transport than was observed in the absence of surfactant. A one-dimensional mathematical model accurately described coupled water flow, surfactant, and solute transport under most experimental conditions. Differences between model predictions and experimental data were observed in the column study performed at the lowest water content (0.115 cm(3)/cm(3)), which was attributed to surfactant adsorption at the air-water interface. These findings demonstrate the potential influence of surfactants additives on unsaturated water flow and solute transport in soils, and demonstrate a methodology to couple these processes in a predictive modeling tool.
BibTeX:
@article{Karagunduz2015,
  author = {Karagunduz, A. and Young, M. H. and Pennell, K. D.},
  title = {Influence of surfactants on unsaturated water flow and solute transport},
  journal = {Water Resources Research},
  year = {2015},
  volume = {51},
  number = {4},
  pages = {1977--1988},
  url = {://WOS:000354733500006},
  doi = {10.1002/2014wr015845}
}
Kayahan E, Bahsi ZB, Oral AY and Sezer M (2015), "Porous Silicon Based Sensor for Organic Vapors", Acta Physica Polonica A. Vol. 127(4), pp. 1400-1402.
Abstract: Porous silicon (PS) has been an attractive material for enhancing optical properties of silicon. Its large surface area for sensor applications and compatibility with silicon-based technologies has been a driving force for further technology development. In this stud of PS to sense at room temperature organic vapors such as acetone, trichloroethylene and hexane, which are harmful to human health, has been investigated. Electrical (DC) and photo-luminescence (PL) measurements in a controlled atmosphere (nitrogen gas and an organic vapor mix) were performed to test the sensor response towards the organic vapors. It was found that PS surface is very sensitive against these vapors. if he experimental results also suggested that PS can be used as a new electro-optical material to sense harmful vapors.
BibTeX:
@article{Kayahan2015,
  author = {Kayahan, E. and Bahsi, Z. B. and Oral, A. Y. and Sezer, M.},
  title = {Porous Silicon Based Sensor for Organic Vapors},
  journal = {Acta Physica Polonica A},
  year = {2015},
  volume = {127},
  number = {4},
  pages = {1400--1402},
  url = {://WOS:000357937100148}
}
Kobya M, Erdem N and Demirbas E (2015), "Treatment of Cr, Ni and Zn from galvanic rinsing wastewater by electrocoagulation process using iron electrodes", Desalination and Water Treatment. Vol. 56(5), pp. 1191-1201.
Abstract: Galvanizing plants contain reasonable amounts of heavy metal ions which pose a serious risk to humans, animals and the environment. In the present study, removal efficiencies of Cr, Ni and Zn from galvanic rinse wastewater (GRW) by electrocoagulation (EC) process using iron plate electrodes were investigated in a laboratory scale EC reactor. The effects of operational variables, such as operating time (0-50min), current density (10-40A/m(2)), initial pH(i) (2.4-6.4) and electrode connection modes (MP-P: monopolar-parallel, MP-S: monopolar-serial and BP-S: bipolar-serial), on the removal efficiencies of heavy metals were explored to determine the optimum operating conditions. Removal efficiencies of 99.77% for Cr, 85.62% for Ni and 99.04% for Zn at the optimum operating conditions (pH(i) 5.4, current density of 30A/m(2), operating time of 30min and MP-P electrode connection mode) were obtained. The results showed that Cr, Ni and Zn removal efficiencies from GRW increased with increasing current density and pH at MP-P electrode connection mode. The results showed that EC can effectively reduce metal ions to a very low level. Amount of sludge generated and operating cost at the optimum conditions during the EC process were calculated as 2.32kg/m(3) and 0.70Euro/m(3). This study revealed that the EC process was very effective for removal of Cr, Ni and Zn from GRW.
BibTeX:
@article{Kobya2015,
  author = {Kobya, M. and Erdem, N. and Demirbas, E.},
  title = {Treatment of Cr, Ni and Zn from galvanic rinsing wastewater by electrocoagulation process using iron electrodes},
  journal = {Desalination and Water Treatment},
  year = {2015},
  volume = {56},
  number = {5},
  pages = {1191--1201},
  url = {://WOS:000362845800006},
  doi = {10.1080/19443994.2014.951692}
}
Kocakusakoglu A, Daglar M, Konyar M, Yatmaz HC and Ozturk K (2015), "Photocatalytic activity of reticulated ZnO porous ceramics in degradation of azo dye molecules", Journal of the European Ceramic Society. Vol. 35(10), pp. 2845-2853.
Abstract: Reticulated ZnO ceramics with an open cell three-dimensional network structure were processed in the present study by polymer sponge replication method. The fabricated highly porous ceramics were used as catalysts in ultraviolet (UV) light-assisted degradation of an azo dye (Reactive Red 180 (RR180)). Decolorization of a model 50 mg/L aqueous solution of RR180 and removal of its by-products (total organic carbon (TOC) efficiencies) were significantly improved by this reticulated ZnO structure as compared with those of "solid" plate-shaped catalysts produced by tape casting method for our previous investigations. After 180 min total processing time for the 500 mL solution under UVC irradiation and for the same amount of catalyst (11 g), the performances of 82.6% and 48.0% for color removal and 18.3% and 5.5% for TOC removal were reached in the presence of the reticulated and the plate-shaped ZnO catalysts, respectively. (C) 2015 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Kocakusakoglu2015,
  author = {Kocakusakoglu, A. and Daglar, M. and Konyar, M. and Yatmaz, H. C. and Ozturk, K.},
  title = {Photocatalytic activity of reticulated ZnO porous ceramics in degradation of azo dye molecules},
  journal = {Journal of the European Ceramic Society},
  year = {2015},
  volume = {35},
  number = {10},
  pages = {2845--2853},
  url = {://WOS:000355353800015},
  doi = {10.1016/j.jeurceramsoc.2015.03.042}
}
Odabasi M, Cetin B and Bayram A (2015), "Persistent Organic Pollutants (POPs) on Fine and Coarse Atmospheric Particles Measured at Two (Urban and Industrial) Sites", Aerosol and Air Quality Research. Vol. 15(5), pp. 1894-+.
Abstract: Particle size is an important parameter in terms of human health effects, fate and transport of pollutants associated with particulate matter (PM). Persistent organic pollutant (POP) (i.e., PAHs, PCBs, PBDEs, and OCPs) concentrations were measured on fine (d(p) < 2.5 mu m) and coarse (2.5 mu m < d(p) < 10 mu m) aerosol samples collected at two (Urban and Industrial) sites in Izmir, Turkey. POP concentrations were similar to 2 times higher at the Industrial site due to the local sources (i.e., scrap processing iron-steel plants, ship-breaking activities, a petroleum refinery, and a petrochemical plant) that were recently shown to be hot spots emitting these pollutants. The size distribution of particle-phase POPs indicated that they were mostly (> 50%) associated with fine PM. The larger contribution of all POP compounds to fine PM could be attributed to the higher sorption capacity of fine PM because of its relatively higher organic matter content compared to coarse PM. Fine PM fraction of POPs significantly increased with octanol-air partition coefficient (K-OA) (p < 0.01) since larger K-OA values favor the partitioning of POPs to PM. Relationships between fine PM percent and meteorological parameters (i.e., temperature and wind speed) were also investigated. Fine PM percent decreased with temperature and the correlations were significant for 51% of the compounds (p < 0.01), suggesting that the decrease in K-OA with increasing temperature results in less partitioning to PM. Fine PM fraction also decreased with wind speed (p < 0.01 for the 52% of the compounds) that could be attributed to increased resuspension of contaminated coarse particles with increasing wind speed. Using the experimental deposition velocities reported for several POPs in the study area it was shown that dry particle deposition velocity significantly decreases with increasing fine PM fraction (p < 0.01). This indicates that the increase in fine fraction of POPs with decreasing volatility may have important implications for their environmental fate and transport.
BibTeX:
@article{Odabasi2015,
  author = {Odabasi, M. and Cetin, B. and Bayram, A.},
  title = {Persistent Organic Pollutants (POPs) on Fine and Coarse Atmospheric Particles Measured at Two (Urban and Industrial) Sites},
  journal = {Aerosol and Air Quality Research},
  year = {2015},
  volume = {15},
  number = {5},
  pages = {1894-+},
  url = {://WOS:000361971500017},
  doi = {10.4209/aaqr.2015.02.0118}
}
Oguz E, Keskinler B and Celik C (2015), "Investigation on the Removal of COD from Colored Aqueous Solutions with O-3, H2O2, HCO3-, and PAC", Ozone-Science & Engineering. Vol. 37(1), pp. 62-70.
Abstract: In this study, chemical oxygen demand (COD) was removed using different processes containing O-3, H2O2, HCO3-, and powder activated carbon (PAC) from the synthetic dye solutions. The effects of the experimental parameters such as temperature, ozone dose, dye concentration, pH, and time on the removal of COD were investigated. The Taguchi method was applied to determine the optimum conditions. An orthogonal array L-18 (2(1) * 3(7)) experimental design plan was selected to define the optimum conditions. In addition, the mechanism of the COD removal was explained on the basis of the results of Fourier transform infrared (FTIR) spectroscopy. To gain information about COD removal mechanism at various pHs, electrophoretic mobilities of particles were measured. The chosen experimental parameters and their ranges are: [GRAPHICS] (0-39 mM); temperature (18-70 degrees C); ozone dose (164-492 mg/min); dye concentration (200-600 ppm); PAC (0-1.5 g); H2O2 (0-0.056 mM); pH (3-12); and time (10-30 min). Under these optimum conditions, it was found that the COD removal efficiency from the synthetic dye solutions was 98%.
BibTeX:
@article{Oguz2015,
  author = {Oguz, E. and Keskinler, B. and Celik, C.},
  title = {Investigation on the Removal of COD from Colored Aqueous Solutions with O-3, H2O2, HCO3-, and PAC},
  journal = {Ozone-Science & Engineering},
  year = {2015},
  volume = {37},
  number = {1},
  pages = {62--70},
  url = {://WOS:000348727800001},
  doi = {10.1080/01919512.2014.911076}
}
Oral ZBB (2015), "Evaluation of Refractive Index Variations of TiO2:SiO2:Zr Thin Films by Molar Ratio", Acta Physica Polonica A. Vol. 127(4), pp. 1314-1316.
Abstract: Zr-doped and undoped TiO2-SiO2 thin films were fabricated by using sol-gel dip coating. TiO2:SiO2:Zr films with different molar ratio were coated on glass substrates. Refractive indexes and the thicknesses of thin films were measured with Metricon 2010 Prism Coupler. The theoretical and measured refractive indexes of thin films were found to be consistently changing with molar ratio. The measured refractive indexes of thin films were lower than the theoretical ones due to the porosity of the structure.
BibTeX:
@article{Oral2015,
  author = {Oral, Z. B. B.},
  title = {Evaluation of Refractive Index Variations of TiO2:SiO2:Zr Thin Films by Molar Ratio},
  journal = {Acta Physica Polonica A},
  year = {2015},
  volume = {127},
  number = {4},
  pages = {1314--1316},
  url = {://WOS:000357937100127}
}
Ozturk N, Ergenekon P, Seckin GO and Bayir S (2015), "Spatial Distribution and Temporal Trends of VOCs in a Highly Industrialized Town in Turkey", Bulletin of Environmental Contamination and Toxicology. Vol. 94(5), pp. 653-660.
Abstract: An extensive monitoring study of volatile organic compounds (VOCs) was conducted at sites across the highly industrialized town of Dilovasi, northern Turkey to determine temporal and spatial trends in pollutant concentrations and relate to the effects of source locations, meteorology, and topography. Two-week passive samplers (Tenax tubes) were deployed at twelve sites from February to December 2012 and analysed using thermal desorption and gas chromatography with mass spectrometric detection (TD-GC-MS). Sampled total VOC (TVOC) levels were highest in the July through October period and were highest at low-altitude sites near industry facilities and vehicle traffic sources (148.3 A mu g/m(3) at site 11, 154.1 A mu g/m(3) at site 10) and lowest at high-altitude sites located furthest upwind from industry and traffic sources (78.4 A mu g/m(3) at site 5 and 78.5 A mu g/m(3) at site 6). Analysis of "T/B" ratios suggested that contributions to ambient VOC in Dilovasi are dominated by the town's industrial sources. Meteorological conditions and the town's basin topography were also found to significantly influence the city's air quality, with strong winds from the NE observed to correlate with periods of higher sampled TVOC. Compared with other industrialized urban centers, the study revealed that there is significant toluene pollution in Dilovasi and recommended enhanced continuous monitoring at the city's industrial and residential zones.
BibTeX:
@article{Ozturk2015,
  author = {Ozturk, N. and Ergenekon, P. and Seckin, G. O. and Bayir, S.},
  title = {Spatial Distribution and Temporal Trends of VOCs in a Highly Industrialized Town in Turkey},
  journal = {Bulletin of Environmental Contamination and Toxicology},
  year = {2015},
  volume = {94},
  number = {5},
  pages = {653--660},
  url = {://WOS:000352614400019},
  doi = {10.1007/s00128-015-1506-8}
}
Polat F, Dogan HM, Buhan E, Kilic OM, Yilmaz DS and Buhan SD (2015), "ACCUMULATION AND BEHAVIOR OF SOME HEAVY METALS IN THE MAIN COMPONENTS OF ZINAV LAKE BASIN ECOSYSTEM", Fresenius Environmental Bulletin. Vol. 24(1A), pp. 180-187.
Abstract: Effects of Pb, Cu, Zn, Fe, Co, Al, and Cd on the ecosystem of Zinav Lake Basin in Turkey were investigated between 2011 and 2013. The ecosystem was handled in seven main components including fish, macrophyte, sediment, water, benthos, plankton, and soil. Heavy metal contents of the main components were determined by using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) and field samples. Relationships among the heavy metal contents of ecosystem components were investigated by using correlation (Pearson) analysis. Hierarchical Clustering Analysis (RCA) was applied to delineate the similar subgroups of ecosystem components according to their heavy metal contents. Fe, Al and Zn were found maximum and Cd was found minimum in almost all ecosystem components except plankton. The accumulation order of heavy metal levels was found as soil > sediment > macrophyte > fish = benthos > water > plankton (except Fe). Al, Co, Cu, Fe, and Zn behave similar in the ecosystem. However, Pb and Cd did not show any similarities neither to each other nor to the others.
BibTeX:
@article{Polat2015,
  author = {Polat, F. and Dogan, H. M. and Buhan, E. and Kilic, O. M. and Yilmaz, D. S. and Buhan, S. D.},
  title = {ACCUMULATION AND BEHAVIOR OF SOME HEAVY METALS IN THE MAIN COMPONENTS OF ZINAV LAKE BASIN ECOSYSTEM},
  journal = {Fresenius Environmental Bulletin},
  year = {2015},
  volume = {24},
  number = {1A},
  pages = {180--187},
  url = {://WOS:000351332400004}
}
Sik E, Kobya M, Demirbas E, Oncel MS and Goren AY (2015), "Removal of As(V) from groundwater by a new electrocoagulation reactor using Fe ball anodes: optimization of operating parameters", Desalination and Water Treatment. Vol. 56(5), pp. 1177-1190.
Abstract: Removal of As(V) from groundwater by a new air-injected electrocoagulation (EC) reactor using iron (Fe) ball anodes was investigated and the operating conditions were optimized. Effects of operating parameters such as initial pH (pH(i): 6.5-8.5), current (i: 0.1-0.5 A), operating time (t(EC): 1-3min), size of Fe anode ball (d(p): 5-10mm), initial As(V) concentration (C-o: 50-150g/L), air flow rate (Q(air): 2-10L/min), and column height of Fe ball (h: 2-8cm) in the EC reactor were evaluated with a three-level factorial design viz. Box-Behnken statistical experiment design. The model program provided with responses such as effluent As(V) concentration, removal efficiency, and operating cost for the EC process. Analysis of variance for all variables had confirmed the predicted models by the experimental design within 95% confidence level (R-2: 0.94, adj-R-2: 0.87), which ensured a satisfactory adjustment of the quadratic model with the experimental data. The maximum removal efficiency of As(V), minimum operating cost, and lowest effluent concentration at the optimized conditions (pH(i) 7.2, 0.5 A, 1.2min, 5mm ball size, column height of 4.8cm, and 9.9L/min) for initial concentration of 100g/L were obtained as 99.2%, 0.031$/m(3), and 0.4g/L, respectively.
BibTeX:
@article{Sik2015,
  author = {Sik, E. and Kobya, M. and Demirbas, E. and Oncel, M. S. and Goren, A. Y.},
  title = {Removal of As(V) from groundwater by a new electrocoagulation reactor using Fe ball anodes: optimization of operating parameters},
  journal = {Desalination and Water Treatment},
  year = {2015},
  volume = {56},
  number = {5},
  pages = {1177--1190},
  url = {://WOS:000362845800005},
  doi = {10.1080/19443994.2014.951691}
}
Simsek H, Kobya M, Khan E and Bezbaruah AN (2015), "Removal of aqueous cyanide with strongly basic ion-exchange resin", Environmental Technology. Vol. 36(13), pp. 1612-1622.
Abstract: The removal of cyanide (CN-) from aqueous solutions using a strongly basic ion-exchange resin, Purolite A-250, was investigated. The effects of contact time, initial CN- concentration, pH, temperature, resin dosage, agitation speed, and particle size distribution on the removal of CN- were examined. The adsorption equilibrium data fitted the Langmuir isotherm very well. The maximum CN- adsorption capacity of Purolite A-250 was found to be 44 mg CN- g(-1) resin. More than 90% CN- adsorption was achieved for most CN- solutions (50, 100, and 200 mg CN- L-1) with a resin dose of 2 g L-1. The equilibrium time was similar to 20 min, optimum pH was 10.0-10.5, and optimum agitation speed was 150 rpm. An increase in adsorption of CN- with increasing resin dosage was observed. Adsorption of CN- by the resin was marginally affected (maximum 4% variation) within an environmentally relevant temperature range of 20-50 degrees C. Fixed-bed column (20.5 mm internal diameters) experiments were performed to investigate the effects of resin bed depth and influent flow rate on breakthrough behaviour. Breakthrough occurred in 5 min for 0.60 cm bed depth while it was 340 min for 5.40 cm bed depth. Adsorption capacity was 25.5 mg CN- g(-1) for 5 mL min(-1) flow rate and 3.9 mg CN- g(-1) for 20 mL min(-1) flow rate. The research has established that the resin can be effectively used for CN- removal from aqueous solutions.
BibTeX:
@article{Simsek2015,
  author = {Simsek, H. and Kobya, M. and Khan, E. and Bezbaruah, A. N.},
  title = {Removal of aqueous cyanide with strongly basic ion-exchange resin},
  journal = {Environmental Technology},
  year = {2015},
  volume = {36},
  number = {13},
  pages = {1612--1622},
  url = {://WOS:000351845000002},
  doi = {10.1080/09593330.2014.999829}
}
Turkay O, Inan H and Dimoglo A (2015), "Experimental study of humic acid degradation and theoretical modelling of catalytic ozonation", Environmental Science and Pollution Research. Vol. 22(1), pp. 202-210.
Abstract: The efficiency of TiO2 as a catalyst in the ozonation of humic acid (HA) was evaluated in a comprehensive manner. Ozonation, catalytic ozonation and adsorption experiments were conducted using both synthetic HA solution and natural water. HA degradation was evaluated in terms of DOC, VIS400 and UV254. It was shown that the addition of catalyst positively affects the mechanism of ozonation. An increase in HA degradation was observed for all these parameters. The impact of catalyst dose and initial pH value of HA on the efficacy of catalytic ozonation was investigated. The highest removal efficiencies were achieved with the dose of 1 g l(-1) of TiO2 (Degussa P-25) and in the acidic pH region. The catalytic ozonation process was efficient also on natural water component although not at the same level as it was on synthetic water. The adsorptive feature of P-25 was considered to have a clear evidence of the catalytic ozonation mechanism. The mechanism of catalysis on the surface of metal oxides was elucidated with the help of quantum-chemical calculations. In the framework of Density Function Theory (DFT), the O-3 decomposition was calculated in the catalytic and non-catalytic processes. Donor-acceptor properties of the frontier (highest occupied and lowest unoccupied molecular orbitals, HOMO/LUMO) orbitals are discussed. Electron density distribution and reaction mechanism of superoxide particles formation, which participate in the process of HA ozonation are analyzed.
BibTeX:
@article{Turkay2015,
  author = {Turkay, O. and Inan, H. and Dimoglo, A.},
  title = {Experimental study of humic acid degradation and theoretical modelling of catalytic ozonation},
  journal = {Environmental Science and Pollution Research},
  year = {2015},
  volume = {22},
  number = {1},
  pages = {202--210},
  url = {://WOS:000347407200012},
  doi = {10.1007/s11356-014-3326-5}
}
Tursun Y and Keskinler B (2015), "DETERMINING THE EFFECTS OF INDUSTRIAL DISCHARGES ON URBAN WASTEWATER CHARACTERISTICS AND THE PLANT OPERATION, INSPECTION OF INDUSTRIAL DISCHARGES", Fresenius Environmental Bulletin. Vol. 24(10B), pp. 3524-3531.
Abstract: Industrial waste-waters should be discharged into the sewer system at the place of origin, following a pre-treatment process. Thus, it could be ensured that the wastewater discharge into the sewer system is below the limit thresholds. It is of utmost importance that the industries fulfill their legal responsibility for pre-treatment, as this helps in secondary treatment efficiency. In order to ensure this, the operation of and discharge of existing treatment plants should be inspected on a regular basis. In this study, the 42 Evler Wastewater Treatment Plant (WIT) under the General Directorate of Kocaeli Water,Sewerage Administration (ISU) was characterized, and the industrial discharges effects on the general wastewater features and their impact to general operation were examined. It was concluded that the industries did not observe discharge limits as specified in the Regulations for Wastewater Discharge into Sewage (AKDY). It was also be noted that, if the regulations were observed, the sludge production, oxygen demand, and energy costs could be reduced by 63, 72, and 72%, respectively. It was observed that the yeast industry and domestic wastewaters are two of the largest sources of impact on this wastewater treatment plant. All industries located in this area are examined by ISU inspection units, and the results obtained from the analyses of the samples collected during these inspections, were not compatible with the urban WIT results; the only explanation for this was illegal discharge. At the end of this study, it was suggested that the industrial inspections should be conducted by more technological methods and more conventional methods should be abandoned.
BibTeX:
@article{Tursun2015,
  author = {Tursun, Y. and Keskinler, B.},
  title = {DETERMINING THE EFFECTS OF INDUSTRIAL DISCHARGES ON URBAN WASTEWATER CHARACTERISTICS AND THE PLANT OPERATION, INSPECTION OF INDUSTRIAL DISCHARGES},
  journal = {Fresenius Environmental Bulletin},
  year = {2015},
  volume = {24},
  number = {10B},
  pages = {3524--3531},
  url = {://WOS:000366880600017}
}
Ucler N, Engin GO, Kocken HG and Oncel MS (2015), "Game theory and fuzzy programming approaches for bi-objective optimization of reservoir watershed management: a case study in Namazgah reservoir", Environmental Science and Pollution Research. Vol. 22(9), pp. 6546-6558.
Abstract: In this study, game theory and fuzzy programming approaches were used to balance economic and environmental impacts in the Namazgah reservoir, Turkey. The main goals identified were to maximize economic benefits of land use and to protect water quality of reservoir and land resources. Total phosphorous load (kg ha(-1) year(-1)) and economic income (USD ha(-1) year(-1)) from land use were determined as environmental value and economic value, respectively. The surface area of existing land use types, which are grouped under 10 headings according to the investigations on the watershed area, and the constraint values for the watershed were calculated using aerial photos, master plans, and basin slope map. The results of fuzzy programming approach were found to be very close to the results of the game theory model. It was concluded that the amount of fertilizer used in the current situation presents a danger to the reservoir and, therefore, unnecessary fertilizer use should be prevented. Additionally, nuts, fruit, and vegetable cultivation, instead of wheat and corn cultivation, was found to be more suitable due to their high economic income and low total phosphorus (TP) load. Apart from agricultural activities, livestock farming should also be considered in the area as a second source of income. It is believed that the results obtained in this study will help decision makers to identify possible problems of the watershed.
BibTeX:
@article{Ucler2015,
  author = {Ucler, N. and Engin, G. O. and Kocken, H. G. and Oncel, M. S.},
  title = {Game theory and fuzzy programming approaches for bi-objective optimization of reservoir watershed management: a case study in Namazgah reservoir},
  journal = {Environmental Science and Pollution Research},
  year = {2015},
  volume = {22},
  number = {9},
  pages = {6546--6558},
  url = {://WOS:000353046600015},
  doi = {10.1007/s11356-015-4181-8}
}
Ulu F, Barisci S, Kobya M and Sillanpaa M (2015), "An evaluation on different origins of natural organic matters using various anodes by electrocoagulation", Chemosphere. Vol. 125, pp. 108-114.
Abstract: In this investigation, natural organic matters (NOM) of different origins (commercial, terrestrial and natural water) were treated by electrocoagulation (EC) process using aluminum, iron and hybrid electrodes. Electrode type effect on removal efficiency was observed for each NOM (commercial, terrestrial, and natural). The results were presented as dissolved organic carbon (DOC) (mg L-1) and UV/VIS absorbance (cm(-1)). The specific UV absorbance (SUVA) was determined before and after treatment of water. The lowest effluent concentration was obtained as 5.05 mg L-1 with hybrid electrode for natural NOM source at its original pH 7.3. In addition, among the metal types, the best UV-abs-254 removal efficiency was obtained as 92.4% with 0.0312 cm(-1) by hybrid electrode at the end of the process. The color removal efficiency of water occurred successfully by Al and hybrid electrodes. Aquatic NOM source was the most resistant to EC treatment with DOC reduction of 71.1%, 59.8%, and 68.6% for Al, Fe and hybrid electrodes, respectively. Zeta potential and floc size of colloids were observed during the process for the determination of destabilization level of natural organic matters in EC process. Fast coagulation or flocculation and incipient instability were formed during electrolysis time for Al and Fe electrode, respectively. SUVA value was reduced to below 2 for three NOM sources studied. The EC process was shown to be a viable for different NOM sources with various metals. (C) 2014 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Ulu2015,
  author = {Ulu, F. and Barisci, S. and Kobya, M. and Sillanpaa, M.},
  title = {An evaluation on different origins of natural organic matters using various anodes by electrocoagulation},
  journal = {Chemosphere},
  year = {2015},
  volume = {125},
  pages = {108--114},
  url = {://WOS:000351646800014},
  doi = {10.1016/j.chemosphere.2014.11.063}
}
Aydiner C, Sen U, Topcu S, Sesli D, Ekinci D, Altinay AD, Ozbey B, Koseoglu-Imer DY and Keskinler B (2014), "Techno-economic investigation of water recovery and whey powder production from whey using UF/RO and FO/RO integrated membrane systems", Desalination and Water Treatment. Vol. 52(1-3), pp. 123-133.
Abstract: As a by-product of dairy industry with high pollutant capacity, uncontrolled discharges of cheese whey result in serious pollution problems in the environment. Besides, recovery of water and whey powder in a whey stream has come to the fore as an important one of whey control strategies in environmental pollution. In that sense, the feasibility of water recovery and whey powder production from whey using integrated membrane processes was techno-economically investigated in this study. The study was focused on three case studies including different process scenarios were executed with laboratory-scale experiments in order to determine the technical performances of processes. The process scenarios were selected as following: the ultrafiltration/reverse osmosis (UF/RO), the forward osmosis/reverse osmosis (FO/RO) with NaCl draw solution and forward osmosis/reverse osmosis including thermolysis (FO/T/RO) at 60 degrees C for concentrating NH4HCO3 draw solution. The real-scale costs for the processes were estimated separately for each scenario using the process modeling and cost estimation software program. The results revealed that UF/RO system is an effective option in whey treatment. FO/T/RO process supplied relatively low-economic performance with 9years payback, $353,000 net present value (NPV) and moderate water recovery value with 47.7%. However, FO/RO process seemed to be a featured alternative with the highest water recovery of 77.4%, the whey powder production of 98,874 entity/year, and NPV of $12,347,000 and also an inevitable result of 0.8years payback lower than that of UF/RO. These results proved that FO/RO system with NaCl draw solution could be successfully employed for both water recovery and whey powder production from whey when compared to UF/RO system known as widely used.
BibTeX:
@article{Aydiner2014,
  author = {Aydiner, C. and Sen, U. and Topcu, S. and Sesli, D. and Ekinci, D. and Altinay, A. D. and Ozbey, B. and Koseoglu-Imer, D. Y. and Keskinler, B.},
  title = {Techno-economic investigation of water recovery and whey powder production from whey using UF/RO and FO/RO integrated membrane systems},
  journal = {Desalination and Water Treatment},
  year = {2014},
  volume = {52},
  number = {1-3},
  pages = {123--133},
  url = {://WOS:000330106200011},
  doi = {10.1080/19443994.2013.786655}
}
Aydiner C, Sen U, Topcu S, Ekinci D, Altinay AD, Koseoglu-Imer DY and Keskinler B (2014), "Techno-economic viability of innovative membrane systems in water and mass recovery from dairy wastewater", Journal of Membrane Science. Vol. 458, pp. 66-75.
Abstract: Viability of innovative treatment systems in recovery of water and mass from dairy wastewater was techno-economically investigated. Lab-scale experiments were carried out for water recovery from whey wastewater using two combined membrane processes as forward osmosis (FO)/membrane distillation (MD) and MD/reverse osmosis (RO). Raw whey was concentrated to the solid contents of 21.0% and 25.8% by FO/MD and MD/RO, respectively. Production of commercial whey powders was successfully accomplished by spray drying of the concentrated whey streams. Full-scale costs of both systems were individually estimated using process modeling and cost estimation software. The simulations for a design influent of 100 m(3)/clay showed that water can be recovered in sufficient quality to be reused in cheese production and the recovered amount increases up to 66-68% compared to 30% for that of UF/RD system. Besides, both treatment systems yielded a return of 12-13 million $ with annual net profit of about 800,000 $ as competing with UF/RO. Pay back times of the system investments were determined as satisfactory as under 1 year clue to annual revenues of about 3.4 million $ from water recovery and whey powder selling. The innovative systems studied seemed to have conclusively enabled more sustainable dairy waste management with good economic benefits. (C) 2014 Elsevier B.V. All rights reserved.
BibTeX:
@article{Aydiner2014a,
  author = {Aydiner, C. and Sen, U. and Topcu, S. and Ekinci, D. and Altinay, A. D. and Koseoglu-Imer, D. Y. and Keskinler, B.},
  title = {Techno-economic viability of innovative membrane systems in water and mass recovery from dairy wastewater},
  journal = {Journal of Membrane Science},
  year = {2014},
  volume = {458},
  pages = {66--75},
  url = {://WOS:000333421200007},
  doi = {10.1016/j.memsci.2014.01.058}
}
Barisci S, Ulu F, Sarkka H, Dimoglo A and Sillanpaa M (2014), "Electrosynthesis of Ferrate (VI) ion Using High Purity Iron Electrodes: Optimization of Influencing Parameters on the Process and Investigating Its Stability", International Journal of Electrochemical Science. Vol. 9(6), pp. 3099-3117.
Abstract: This study is focused on the determination of optimum conditions for ferrate (VI) production and its stability. The effect of various operating parameters, such as NaOH concentration, current density, temperature and electrolysis duration on the yield of electrochemical ferrate (VI) ion production was investigated for high purity iron electrodes. Cyclic Voltammetry (CV) studies were carried out to characterize a process that takes place on the working iron electrode. The surface of high purity iron electrode was analyzed by Scanning Electron Microscopy (SEM). Electrosynthesized ferrate (VI) ion stability at different conditions was also investigated. Factors influencing the stability were initial ferrate (VI) ion concentration, alkalinity, temperature, and pH of the solution. Ferrate (VI) ion showed high stability at higher alkalinity, lower temperatures, increasing ferrate (VI) ion concentration and pH in the range between 9.2 and 10. Current efficiency and energy consumption were used for the optimum parameters determination for the ferrate (VI) production. According to the experiments, the optimum conditions were NaOH (as anolyte) concentration of 20 M, current density of 1.47 mA/cm(2), and temperature of 30 +/- 1 degrees C with electrolysis duration of 1.5 hours. Ferrate (VI) ion solutions with contents up to 2.0 mM were produced in the electrochemical cell.
BibTeX:
@article{Barisci2014,
  author = {Barisci, S. and Ulu, F. and Sarkka, H. and Dimoglo, A. and Sillanpaa, M.},
  title = {Electrosynthesis of Ferrate (VI) ion Using High Purity Iron Electrodes: Optimization of Influencing Parameters on the Process and Investigating Its Stability},
  journal = {International Journal of Electrochemical Science},
  year = {2014},
  volume = {9},
  number = {6},
  pages = {3099--3117},
  url = {://WOS:000334493300033}
}
Barisci S and Oncel MS (2014), "THE DISPOSAL OF COMBED COTTON WASTES BY PYROLYSIS", International Journal of Green Energy. Vol. 11(3), pp. 255-266.
Abstract: The main objective of this work is to propose an alternative method for disposing of combed cotton wastes consisting of swatches with various sizes and shapes. For this purpose, pyrolysis of combed cotton waste was conducted in a fixed bed reactor with the final temperatures of 450, 500, 550, and 600 degrees C. Effect of the experimental conditions such as temperature, catalyst type on the formation of liquid, gas, and char products were investigated and product yields were measured. The highest liquid product efficiency was achieved with 29.74% at the temperature of 550 degrees C. CaCO3 and Na2CO3 were used as catalysts. Na2CO3 was found to be more effective catalyst than CaCO3 The properties of the obtained liquid product were analyzed by high performance liquid chromatography (HPLC). Furans, ketones, aldehydes, less carboxylic acids, and hydrocarbons were detected in the content of liquid product. The calorific values of raw material, liquid product, and char were also determined by using IKA C 200 calorimeter. The results clearly indicated that both temperature and catalyst type affect the formation of liquid product. Pyrolysis may be a useful way of waste management for energy and material recovery.
BibTeX:
@article{Barisci2014a,
  author = {Barisci, S. and Oncel, M. S.},
  title = {THE DISPOSAL OF COMBED COTTON WASTES BY PYROLYSIS},
  journal = {International Journal of Green Energy},
  year = {2014},
  volume = {11},
  number = {3},
  pages = {255--266},
  url = {://WOS:000324613500003},
  doi = {10.1080/15435075.2013.772516}
}
Barlik N and Keskinler B (2014), "Sulfonation of crosslinked styrene/divinyl benzene copolymer beads formed from porous foam and ion adsorption of copper by them: column adsorption modeling", Water Science and Technology. Vol. 69(2), pp. 286-292.
Abstract: The porous foam is made by the polymerisation of a high internal phase emulsion and it is a highly porous, low density, open cellular material. Surface properties of the foam were chemically modified via a sulfonation process. Sulfonation added -SO3-H+ groups to the polymer matrix. The ion adsorption behavior of copper ions on sulfonated polymer beads, depending on inlet concentration (10-60 mg/L), pH of inlet solution (2.00-5.20) and flow velocity (1.7-11.4 m/h) was studied. It was shown that the amount of copper adsorbed was not affected with increasing concentration of feed solutions and flow velocity. Also the process was highly pH dependent. The maximum removal was 117.96 mg Cu/g dry adsorbent at flow velocity 11.4 m/h. Column experimental tests were conducted to provide data for theoretical modeling and to verify the system performance of the process. A theoretical column model adopted in this work was found to describe well the ion adsorption breakthrough characteristics.
BibTeX:
@article{Barlik2014,
  author = {Barlik, N. and Keskinler, B.},
  title = {Sulfonation of crosslinked styrene/divinyl benzene copolymer beads formed from porous foam and ion adsorption of copper by them: column adsorption modeling},
  journal = {Water Science and Technology},
  year = {2014},
  volume = {69},
  number = {2},
  pages = {286--292},
  url = {://WOS:000331947200008},
  doi = {10.2166/wst.2013.703}
}
Basaran ST, Aysel M, Kurt H, Ergal I, Akarsubasi A, Yagci N, Dogruel S, Cokgor EU, Keskinler B, Sozen S and Orhon D (2014), "Kinetic characterization of acetate utilization and response of microbial population in super fast membrane bioreactor", Journal of Membrane Science. Vol. 455, pp. 392-404.
Abstract: The study investigated the functional relationships between changes in microbial community induced by different sludge ages (SRT) selected for super fast MBR operation on variable process kinetics, fate of soluble microbial products (SMPs) and system performance. Acetate, a simple and separately identifiable compound, was selected as the sole organic carbon source. MBR operation was monitored at steady-state at extremely low SRT levels of 2.0, 1.0 and 0.5 cl and a hydraulic retention time of 1.0 h. Batch experiments were conducted for kinetic evaluation of MBR performance by model evaluation of oxygen uptake rate, polyhydroxybutyric acid and COD profiles. Bacterial DGGE profiles indicated that SRT exerted shifts in the composition of microbial community. Model evaluation of experimental data also confirmed molecular analyses, indicating variable growth kinetics for utilization of acetate and identified high and variable endogenous respiration as a function of SRT. Changes in the microbial community and process kinetics did not affect MBR performance, providing complete depletion of available acetate. Effluent COD remained below 17 mg/L and entirely composed of SMPs. Particle size analysis revealed a bimodal distribution of the wide spectrum of SMPs above 13 nm and below 2 nm. Effective filtration size of the membrane was reduced to 8 nm due to cake filtration effect. The retained fraction of SMPs was in the range of 1-2 mg/L, but accumulated in the reactor volume, same way as biomass. Therefore, the real merit of super fast MBR was the very low levels of SMP generation (14-18 mg COD/L), rather than the effective capture of accumulated COD due to cake filtration. (C) 2013 Elsevier B.V. All rights reserved.
BibTeX:
@article{Basaran2014,
  author = {Basaran, S. T. and Aysel, M. and Kurt, H. and Ergal, I. and Akarsubasi, A. and Yagci, N. and Dogruel, S. and Cokgor, E. U. and Keskinler, B. and Sozen, S. and Orhon, D.},
  title = {Kinetic characterization of acetate utilization and response of microbial population in super fast membrane bioreactor},
  journal = {Journal of Membrane Science},
  year = {2014},
  volume = {455},
  pages = {392--404},
  url = {://WOS:000330952900041},
  doi = {10.1016/j.meinsci.2013.12.035}
}
Bayar S and Karagunduz A (2014), "Influence of electrical field on COD removal and filterability of activated sludge", Desalination and Water Treatment. Vol. 52(7-9), pp. 1316-1323.
Abstract: Three batch reactors were operated in order to investigate the effects of electrocoagulation and electrical field on chemical oxygen demand (COD) degradation rates, efficiencies, and filterability. The first reactor was operated with iron electrode, the second reactor was operated with relatively inert titanium electrode, and the last one was run as control without any electrical field. The electrical field application with iron electrodes increased the COD degradation rates at 0.5 and 2.5V/cm with COD removals around 90%. However, the removal efficiencies decreased down to 70% at 5V/cm. Increases in degradation rates were observed with titanium electrodes with time at all the three voltages. Activated sludge from the reactor with iron electrodes showed excellent filtration properties at 2.5 and 5V/cm experiments. This was attributed to iron precipitates screening membrane foulants and preventing the formation of high resistive cake layer and pore structure rather than floc size increase. Electrocoagulation showed promising results in reducing membrane fouling. A critical voltage gradient should be maintained and the magnitude of iron electrode dissolution should be controlled in the reactor to obtain optimum COD degradation and to enhance filterability. Sludge samples from reactor with titanium electrodes showed poor filterability as voltage gradient increased (at 5V/cm). This was attributed to the elevated soluble protein content (SMPp) concentration due to cell disruption.
BibTeX:
@article{Bayar2014,
  author = {Bayar, S. and Karagunduz, A.},
  title = {Influence of electrical field on COD removal and filterability of activated sludge},
  journal = {Desalination and Water Treatment},
  year = {2014},
  volume = {52},
  number = {7-9},
  pages = {1316--1323},
  url = {://WOS:000331695700009},
  doi = {10.1080/19443994.2013.787952}
}
Celen M, Karpuzcu M, Engin GO, Tetzlaff B and Wendland F (2014), "Modelling total phosphorus input pathways in the Porsuk reservoir catchment in Turkey", Environmental Earth Sciences. Vol. 72(12), pp. 5019-5034.
Abstract: As a country in the Mediterranean region, Turkey must face the effects of climate change on water quality and quantity. Decision support systems are accepted as useful and practical tools for the protection and management of water resources. The need for such tools is rapidly emerging in conjunction with industrial developments in Turkey. Against this background, the empirical area-differentiated phosphorus model MEPhos developed for the mid-European site conditions was transferred and adapted for a representative study area in Turkey, the Porsuk reservoir catchment. Adaption included the development of a model approach to consider the P input into surface waters from septic tanks. For this purpose, several field campaigns were carried out to define characteristic P emission coefficients for septic tanks. In addition, the soil phosphorus content of the top soil was defined to generate reliable input data for the modelling of the P input into surface water via soil erosion in agricultural areas. According to the MEPhos model results, mean annual phosphorous loads of all types of point sources dominate with a percentage of around 57 %. Erosion contributes to 40 % of the total P load and displays the most significant diffuse input pathway. The validation studies conducted between 2007 and 2011 showed a satisfying agreement with the observed values. After validation, the efficiency of measures to reduce P inputs into the Porsuk reservoir was analysed. It was found that most measures to prevent soil erosion seem to be appropriate, whereas measures to reduce P input from point sources seem to be less efficient.
BibTeX:
@article{Celen2014,
  author = {Celen, M. and Karpuzcu, M. and Engin, G. O. and Tetzlaff, B. and Wendland, F.},
  title = {Modelling total phosphorus input pathways in the Porsuk reservoir catchment in Turkey},
  journal = {Environmental Earth Sciences},
  year = {2014},
  volume = {72},
  number = {12},
  pages = {5019--5034},
  url = {://WOS:000345407000025},
  doi = {10.1007/s12665-014-3371-x}
}
Cetin B (2014), "Soil concentrations and source apportionment of polybrominated diphenyl ethers (PBDEs) and trace elements around a heavily industrialized area in Kocaeli, Turkey", Environmental Science and Pollution Research. Vol. 21(13), pp. 8284-8293.
Abstract: Air pollutants are transported by dry deposition, wet deposition, and gas exchange accumulated in soil. Therefore, soil is an important environmental medium reflecting the level and the spatial distribution of air pollutants such as polybrominated diphenyl ethers (PBDEs) and heavy metals. Soil concentrations of seven PBDE congeners and 21 trace elements were determined in a heavily industrialized region (Dilovasi) in Kocaeli, Turkey. At all sites, Sigma 7PBDE concentrations ranged from 0.70 to 203 with a mean value of 26.3 mu g kg(-1) (dry weight). The congener profiles and mass inventories of PBDEs and their interactions with soil organic matter (SOM) were also investigated. BDE-209 was the dominant congener at all sites, followed by BDE-99 and/or -47. The estimated inventory of PBDEs for the Dilovasi district was 310 kg. However, there are several additional industrial regions in Kocaeli city. Considering the total land area, the potential inventory would be much larger for this city. The relationship between the PBDE concentrations in soil and SOM content indicated that factors other than soil properties have a greater influence on soil concentrations. Crustal enrichment factors (EFs) were determined; correlation analysis and factor analysis (FA) were also applied to generated data set to identify and apportion the sources polluting the soil. Sn, Mn, Ca, As, Zn, Pb, and Cd had significantly high average EF values, indicating that their soil concentrations were mainly influenced by anthropogenic activities. In FA, six factors were extracted with a cumulative variance of 84.4 % and industrial activities and traffic were found to be the main factors affecting the soil profile.
BibTeX:
@article{Cetin2014,
  author = {Cetin, B.},
  title = {Soil concentrations and source apportionment of polybrominated diphenyl ethers (PBDEs) and trace elements around a heavily industrialized area in Kocaeli, Turkey},
  journal = {Environmental Science and Pollution Research},
  year = {2014},
  volume = {21},
  number = {13},
  pages = {8284--8293},
  url = {://WOS:000337086600046},
  doi = {10.1007/s11356-014-2825-8}
}
Dizge N (2014), "Performance evaluation of cross-flow membrane system for wastewater reuse from the wood-panels industry", Environmental Technology. Vol. 35(6), pp. 681-690.
Abstract: The objectives of this investigation were to perform a series of lab-scale membrane separation experiments under various operating conditions to investigate the performance behaviour of nanofiltration membrane (NF 270) for wastewater reuse from the wood-panels industry. The operating condition effects, e.g. cross-flow velocity (CFV), trans membrane pressure (TMP) and temperature, on the permeate flux and contaminant rejection efficiency were investigated. Moreover, three different samples: (1) raw wastewater collected from the wood-panels industry; (2) ultrafiltration pre-treated wastewater (UF-NF); and (3) coagulation/flocculation pre-treated wastewater (CF-NF) were employed in this study. The UF-NF was proposed as a pre-treatment process because it could reduce the chemical oxygen demand (COD) effectively with lower energy consumption than CF-NF. The performance of NF 270 membrane was assessed by measurements of the many parameters (pH, conductivity, total dissolved solids, COD, suspended solids, total nitrogen, nitrite, nitrate, and total phosphate) under various operating conditions. It was noted that the contaminant rejection was affected by changing TMP and CFV. It was concluded that the purified water stream can be recycled into the process for water reuse or safely disposed to the river.
BibTeX:
@article{Dizge2014,
  author = {Dizge, N.},
  title = {Performance evaluation of cross-flow membrane system for wastewater reuse from the wood-panels industry},
  journal = {Environmental Technology},
  year = {2014},
  volume = {35},
  number = {6},
  pages = {681--690},
  url = {://WOS:000329153800003},
  doi = {10.1080/09593330.2013.841293}
}
Durmazpinar S, Ilhan N, Demir G, Insel G, Dizge N, Ergenekon P, Erhan E and Keskinler B (2014), "Biological NOx removal by denitrification process in a jet-loop bioreactor: system performance and model development", Environmental Technology. Vol. 35(11), pp. 1358-1366.
Abstract: Nitrogen monoxide (NO) and nitrogen dioxide referred as NOx are one of the most important air pollutants in the atmosphere. Biological NOx removal technologies have been developing to reach a cost-effective control method for upcoming stringent NOx emission standards. The BioDeNOx system was seen as a promising biological NOx control technology which is composed of two reactors, one for absorbing of NO in an aqueous Fe(II)EDTA(2-) solution and the other for subsequent reduction to N-2 gas in a biological reactor by the denitrification process. In this study, instead of two discrete reactors, only one jet-loop bioreactor (JLBR) was utilized as both absorption and denitrification unit and no chelate-forming chemicals were added. In other words, the advantage of better mass transfer conditions of jet bioreactor was used instead of Fe(II)EDTA(2-). The process was named as Jet-BioDeNOx. The JLBR was operated for the removal of NOx from air streams containing 500-3000ppm NOx and the results showed that the removal efficiency was between 81% and 94%. The air to liquid flow ratio (Q(G)/Q(RAS)) varied in the range of 0.07-0.12. Mathematical modelling of the system demonstrated that the removal efficiency strongly depends on this ratio. The high mass transfer conditions prevailed in the reactor provided a competitive advantage on removing NO gas without any requirement of chelating chemicals.
BibTeX:
@article{Durmazpinar2014,
  author = {Durmazpinar, S. and Ilhan, N. and Demir, G. and Insel, G. and Dizge, N. and Ergenekon, P. and Erhan, E. and Keskinler, B.},
  title = {Biological NOx removal by denitrification process in a jet-loop bioreactor: system performance and model development},
  journal = {Environmental Technology},
  year = {2014},
  volume = {35},
  number = {11},
  pages = {1358--1366},
  url = {://WOS:000331357300006},
  doi = {10.1080/09593330.2013.868529}
}
Engin GO, Gurbulak E, Celen M, Ulu F and Oncel MS (2014), "NUTRIENT MODELLING IN COASTAL WATERS OF IZMIT BAY, TURKEY", Fresenius Environmental Bulletin. Vol. 23(12B), pp. 3345-3352.
Abstract: The ECOLab module of the MIKE 3 model based on the coupling between a hydrodynamic part and an ecological part which accounts for mainly the nutrient enrichment was utilized to study nutrient cycles and their contribution to eutrophication in the Izmit Bay located in the Sea of Marmara. The water quality data, including on-site parameters, produced between November 2005 and November 2006 were used for model runs and validation. The samples were collected from 8 different points on the cross-section of the bay at different depths considering the bottom point of the sea bed in order to represent the third dimension. The ecological model used in this study allows creating 3D images/results that simulate the actual situation. The spatial distribution of state variables such as, dissolved Biological Oxygen Demand (BODd), dissolved oxygen (DO), ammonia, nitrate and nitrite, and phosphate concentrations were investigated. The processes, used as arguments in the differential equations involved in ECOLab, were advective dispersive transport, biological, chemical and physical transformation process and settling. According to the model results, the discharges of main streams have a big influence on the variation of the BOD, especially in the coastal and shallow regions. Additionally, the modelled ammonia, nitrate and phosphate concentrations were determined at the discharge points of the four main streams reaching the bay.
BibTeX:
@article{Engin2014,
  author = {Engin, G. O. and Gurbulak, E. and Celen, M. and Ulu, F. and Oncel, M. S.},
  title = {NUTRIENT MODELLING IN COASTAL WATERS OF IZMIT BAY, TURKEY},
  journal = {Fresenius Environmental Bulletin},
  year = {2014},
  volume = {23},
  number = {12B},
  pages = {3345--3352},
  url = {://WOS:000348744900013}
}
Ergenekon P and Ulutas K (2014), "Heavy Metal Content of Total Suspended Air Particles in the Heavily Industrialized Town of Gebze, Turkey", Bulletin of Environmental Contamination and Toxicology. Vol. 92(1), pp. 90-95.
Abstract: Air pollution is a serious environmental problem in industrialized towns, where a significant portion of the residents live in close proximity to factories and major highways with high traffic load. In this study, the ambient air quality in Gebze, an industrial region with an area of 438 km(2) and a population of 300,000, was characterized in terms for total suspended particulate matter and its composition of trace elements, i.e. Cd, Cr, Cu, Fe, Mn, Ni and Pb. Samples were collected using high volume samplers from March to June 2009 at two sites during the day and the night. A significantly higher Cu concentrations during night suggested that Cu emissions were the result of a local source. The known air toxics, Cd and Ni, had average concentrations (34 and 43 ng/m(3), respectively) higher than proposed by the European Union's ambient air quality standards. These results highlight the potential health risks for the local population.
BibTeX:
@article{Ergenekon2014,
  author = {Ergenekon, P. and Ulutas, K.},
  title = {Heavy Metal Content of Total Suspended Air Particles in the Heavily Industrialized Town of Gebze, Turkey},
  journal = {Bulletin of Environmental Contamination and Toxicology},
  year = {2014},
  volume = {92},
  number = {1},
  pages = {90--95},
  url = {://WOS:000329227000017},
  doi = {10.1007/s00128-013-1148-7}
}
Herand BK, Simsek EK, Oncel MS and Ozkan M (2014), "Continuous metal bioremoval by new bacterial isolates in immobilized cell reactor", Annals of Microbiology. Vol. 64(2), pp. 699-706.
Abstract: In this study, four bacterial species isolated from an industrially polluted region at the Istanbul-Kocaeli border were characterized and their efficiencies for bioremoval of Cu2+, Ni2+, Cr3+, Zn2+, and Fe2+ were determined in batch and continuous systems. Strain N4c was used for continuous metal bioremoval in a packed-bed immobilized cell reactor (ICR) with a working volume of 180 ml. ICR was successfully operated for treatment of synthetic wastewater containing 200 mg/l Cu2+ and Ni2+ for 140 and 80 h, respectively. Bioremoval efficiency of ICR for Cu2+ reached around 90 % in the last 3 days of operation at a flow rate of 1 ml/min. Ni2+ bioremoval in ICR was less efficient as the system worked for only 80 h and bioremoval efficiency decreased from 73.3 to 42.8 % during the operation period. Wastewater containing one or two types of metal seems to be a good candidate for treatment with immobilized N4c cells in a continuous system. Survival of the cells in the wastewater was found to be an important parameter affecting bioremoval efficiency in both batch and continuous systems. The ICR used in this study can be scaled up for treatment of industrial wastewaters containing Ni2+ or Cu2+.
BibTeX:
@article{Herand2014,
  author = {Herand, B. K. and Simsek, E. K. and Oncel, M. S. and Ozkan, M.},
  title = {Continuous metal bioremoval by new bacterial isolates in immobilized cell reactor},
  journal = {Annals of Microbiology},
  year = {2014},
  volume = {64},
  number = {2},
  pages = {699--706},
  url = {://WOS:000336277900031},
  doi = {10.1007/s13213-013-0705-y}
}
Inan H, Turkay O and Akkiris C (2014), "Microwave and microwave-alkali effect on barley straw for total sugar yield", International Journal of Global Warming. Vol. 6(2-3), pp. 212-221.
Abstract: Lignocellulose is the most remarkable plant material resource for obtaining energy; however, its utility is restrained by its recalcitrant structure. Therefore, it is necessary to apply a convenient pretreatment method to increase the sugar yield. Microwave pretreatment method assists to break down hard lignin structure for improved degradation of cellulose and releasing of sugar. The objectives of this study are to investigate microwave and microwave-alkali pretreatment efficiency of barley straw before enzymatic hydrolysis. In both pretreatment methods, remarkable findings were obtained as sugar concentration. The maximum reducing total sugar concentration of 354.1 mg/L was achieved after ten minutes of pretreatment time in 30 mL of 3% NaOH solution (w/v) at microwave power of 200 W. The evaluations of scanning electron microscopy (SEM) images were carried out within pretreatment of barley straw as well. The results suggest that microwave and microwave-alkali pretreatment can increase total sugar concentration.
BibTeX:
@article{Inan2014,
  author = {Inan, H. and Turkay, O. and Akkiris, C.},
  title = {Microwave and microwave-alkali effect on barley straw for total sugar yield},
  journal = {International Journal of Global Warming},
  year = {2014},
  volume = {6},
  number = {2-3},
  pages = {212--221},
  url = {://WOS:000344364800007},
  doi = {10.1504/ijgw.2014.061011}
}
Inan H and Alaydin E (2014), "Phosphate and nitrogen removal by iron produced in electrocoagulation reactor", Desalination and Water Treatment. Vol. 52(7-9), pp. 1396-1403.
Abstract: In this study, concentrated iron solution generated by electrocoagulation (EC) process was used for the removal of nutrients from human urine (yellow water). Yellow water was prepared synthetically with major components: nitrogen and phosphorus. As a result of the pH adjustment, nitrogen and phosphorus, which are present in urine, react with electrochemically generated iron solution and then accumulate in the sludge by precipitation. All experiments were done under different pH values for the evaluation of this novel EC nutrient removal process. The effect of the EC treatment on the removal of nutrients was followed by total nitrogen and phosphate measurements and Fourier transform infrared spectroscopy (FTIR). The effects of treatment parameters (pH, iron/phosphate, iron/nitrogen, and iron/nutrient ratios) on the performance of the EC treatment were also examined for the evaluation of applicability of this novel EC method for the treatment of yellow waters. The results show that the pH increase improved phosphate removal efficiencies at definite molar nutrient ratios. The phosphate removal efficiency was approximately 98% at pH 8 for 1:1 of iron/nutrient molar ratio and on the other hand, nitrogen removal was only 21% at pH 8 for 4:1 of iron/urea molar ratio. Total organic carbon (TOC) removal efficiency was reached to 26% of the process. FTIR adsorption spectra were discussed for the sludge obtained.
BibTeX:
@article{Inan2014a,
  author = {Inan, H. and Alaydin, E.},
  title = {Phosphate and nitrogen removal by iron produced in electrocoagulation reactor},
  journal = {Desalination and Water Treatment},
  year = {2014},
  volume = {52},
  number = {7-9},
  pages = {1396--1403},
  url = {://WOS:000331695700019},
  doi = {10.1080/19443994.2013.787950}
}
Karagoz P and Ozkan M (2014), "Ethanol production from wheat straw by Saccharomyces cerevisiae and Scheffersomyces stipitis co-culture in batch and continuous system", Bioresource Technology. Vol. 158, pp. 286-293.
Abstract: In this research, Scheffersomyces stipitis and Saccharomyces cerevisiae in immobilized and suspended state were used to convert pentose and hexose sugars to ethanol. In batch and continuous systems, S. stipitis and S. cerevisiae co-culture performance was better than S. cerevisiae. Continuous ethanol production was performed in packed bed immobilized cell reactor (ICR). In ICR, S. stipitis cells were found to be more sensitive to oxygen concentration and other possible mass transfer limitations as compared to S. cerevisiae. Use of co-immobilized S. stipitis and S. cerevisiae resulted in maximum xylose consumption (73.92%) and 41.68 g/L day ethanol was produced at HRT (hydraulic retention time) of 6 h with wheat straw hydrolysate. At HRT of 0.75 h, the highest amount of ethanol with the values of 356.21 and 235.43 g/L day was produced when synthetic medium and wheat straw hydrolysate were used as feeding medium in ICR, respectively. (C) 2014 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Karagoz2014,
  author = {Karagoz, P. and Ozkan, M.},
  title = {Ethanol production from wheat straw by Saccharomyces cerevisiae and Scheffersomyces stipitis co-culture in batch and continuous system},
  journal = {Bioresource Technology},
  year = {2014},
  volume = {158},
  pages = {286--293},
  url = {://WOS:000334830300040},
  doi = {10.1016/j.biortech.2014.02.022}
}
Keris-Sen UD, Sen U, Soydemir G and Gurol MD (2014), "An investigation of ultrasound effect on microalgal cell integrity and lipid extraction efficiency", Bioresource Technology. Vol. 152, pp. 407-413.
Abstract: In this study, different ultrasound power intensities (0.1-0.5 W mL(-1)) were applied at a frequency of 30 kHz and for durations of 5-60 min to mixed microalgal cultures, one cultivated in BG11 medium, and the other in secondary effluent wastewater. The ultrasonic effect on cell disruption was revealed by increased concentrations of protein and carbohydrate released into the solution, and a decreased concentration of total suspended solids in cell suspension. The highest intercellular material release was achieved at an ultrasonic energy intensity of 0.4 kWh L-1, while the effect of ultrasound on cell disruption was reduced at higher energy intensities. Additionally, the ultrasonic effect on lipid extraction efficiency was studied in the presence of two different solvents, n-hexane and chloroform/methanol mixture. The application of ultrasound at 0.4 kWh L-1, provided 1.5-2.0-fold increase in lipid extraction yields in the presence of the solvents. (C) 2013 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Keris-Sen2014,
  author = {Keris-Sen, U. D. and Sen, U. and Soydemir, G. and Gurol, M. D.},
  title = {An investigation of ultrasound effect on microalgal cell integrity and lipid extraction efficiency},
  journal = {Bioresource Technology},
  year = {2014},
  volume = {152},
  pages = {407--413},
  url = {://WOS:000331460400055},
  doi = {10.1016/j.biortech.2013.11.018}
}
Kilic MS, Korkut S, Hazer B and Erhan E (2014), "Development and operation of gold and cobalt oxide nanoparticles containing polypropylene based enzymatic fuel cell for renewable fuels", Biosensors & Bioelectronics. Vol. 61, pp. 500-505.
Abstract: Newly synthesized gold and cobalt oxide nanoparticle embedded Polypropylene-g-Polyethylene glycol was used for a compartment-less enzymatic fuel cell. Glucose oxidase and bilirubin oxidase were selected as anodic and cathodic enzymes, respectively. Electrode fabrication and EFC operation parameters were optimized to achieve high power output Maximum power density of 23.5 mu W cm(-2) was generated at a cell voltage of +560 mV vs Ag/AgCl, in 100 mM PBS pH 7.4 with the addition of 20 mM of synthetic glucose solution. 20 mu g of polymer amount with 185 mu g of glucose oxidase and 356 mu g of bilirubin oxidase was sufficient to get maximum performance. The working electrodes could harvest glucose, produced during photosynthesis reaction of Carpobrotus Acinaciformis plant, and readily found in real domestic wastewater of Zonguldak City in Turkey. (C) 2014 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kilic2014,
  author = {Kilic, M. S. and Korkut, S. and Hazer, B. and Erhan, E.},
  title = {Development and operation of gold and cobalt oxide nanoparticles containing polypropylene based enzymatic fuel cell for renewable fuels},
  journal = {Biosensors & Bioelectronics},
  year = {2014},
  volume = {61},
  pages = {500--505},
  url = {://WOS:000339692500073},
  doi = {10.1016/j.bios.2014.05.068}
}
Kobya M, Gengec E, Sensoy MT and Demirbas E (2014), "Treatment of textile dyeing wastewater by electrocoagulation using Fe and Al electrodes: optimisation of operating parameters using central composite design", Coloration Technology. Vol. 130(3), pp. 226-235.
Abstract: Textile dyeing wastewater was treated by electrocoagulation using aluminium and iron plate electrodes. Response surface methodology and central composite design were applied in the experiments and in statistical data analysis. A current density of 30-100Am(-2), an initial pH of 4-8, and an operating time of 10-40min were chosen as independent variables, and the chemical oxygen demand, total organic carbon, and turbidity removal efficiencies and the operating cost were selected as responses in the electrocoagulation process. The developed quadratic models for the responses and the experimental data were in good agreement with model predictions statistically (R(2)0.92, Adj R(2)0.82, and Prob>F<0.004). The optimised operating variables (initial pH, current density, and operating time) and the maximum total organic carbon, chemical oxygen demand, and turbidity removal efficiencies for textile dyeing wastewater were 5.5, 63.2Am(-2), 30.4min, 77%, 82%, and 94% for the iron electrode and 5.6, 52.5 Am-2, 33.9min, 68%, 69% and 99% for the aluminium electrode respectively. Minimum operating costs for the iron and aluminium electrodes under optimum conditions were Euro2.1m(-3) (Euro1.0kg(-1) COD) and Euro2.4m(-3) (Euro1.6kg(-1) COD). The iron electrode was found to be superior to the aluminium electrode in terms of removal efficiencies and operating cost for the treatment of textile dyeing wastewater.
BibTeX:
@article{Kobya2014,
  author = {Kobya, M. and Gengec, E. and Sensoy, M. T. and Demirbas, E.},
  title = {Treatment of textile dyeing wastewater by electrocoagulation using Fe and Al electrodes: optimisation of operating parameters using central composite design},
  journal = {Coloration Technology},
  year = {2014},
  volume = {130},
  number = {3},
  pages = {226--235},
  url = {://WOS:000335394000010},
  doi = {10.1111/cote.12090}
}
Kobya M, Akyol A, Demirbas E and Oncel MS (2014), "Removal of Arsenic from Drinking Water by Batch and Continuous Electrocoagulation Processes Using Hybrid Al-Fe Plate Electrodes", Environmental Progress & Sustainable Energy. Vol. 33(1), pp. 131-140.
Abstract: Removals of arsenic from drinking water by electrocoagulation (EC) process using six different combinations of hybrid electrodes (Al-Fe), and Al-Al or Fe-Fe electrodes as all anodes and cathodes in a batch mode were evaluated. The removal process with monopolar series mode at optimum operating conditions (2.50 A/m(2), 150 mu g/L, and pH 7.0) indicated that Fe-Al-Al-Fe (anode-cathode-anode-cathode) hybrid plate electrode pairs were the most efficient choice in terms of arsenic removal efficiency (96% in 1 min) and operating cost (0.00202 Euro/m(3)). The arsenic removal from drinking water by continuous EC (CEC) process using Fe-Al-Al-Fe hybrid plate electrode pairs was also studied with respect to flow rates and initial arsenic concentrations. The effluent arsenic concentration of 10 mu g/L in the CEC process was achieved at 3 min for 0.05 L/min (5.9 mu g/L), 8 min for 0.10 L/min (6.3 mu g/L), and 20 min for 0.20 L/min (8.4 mu g/L), respectively. Amounts of the sludge and operating costs in the CEC process with respect to some experimental parameters such as operating time (3-20 min) and flow rate (0.05-0.20 L/min) at 150 mu g/L were determined as 0.0095-0.025 kg/m(3) and 0.009-0.060 Euro/m(3). (c) 2013 American Institute of Chemical Engineers Environ Prog, 33: 131-140, 2014
BibTeX:
@article{Kobya2014a,
  author = {Kobya, M. and Akyol, A. and Demirbas, E. and Oncel, M. S.},
  title = {Removal of Arsenic from Drinking Water by Batch and Continuous Electrocoagulation Processes Using Hybrid Al-Fe Plate Electrodes},
  journal = {Environmental Progress & Sustainable Energy},
  year = {2014},
  volume = {33},
  number = {1},
  pages = {131--140},
  url = {://WOS:000329309300014},
  doi = {10.1002/ep.11765}
}
Ozkan M, Celik MA, Karagoz P, Yilmaz H and Sengezer C (2014), "Activity of Bdellovibrio on Sludge bacteria and its potential use for cleaning of Membrane Bioreactors", New Biotechnology. Vol. 31, pp. S133-S133.
BibTeX:
@article{Ozkan2014,
  author = {Ozkan, M. and Celik, M. A. and Karagoz, P. and Yilmaz, H. and Sengezer, C.},
  title = {Activity of Bdellovibrio on Sludge bacteria and its potential use for cleaning of Membrane Bioreactors},
  journal = {New Biotechnology},
  year = {2014},
  volume = {31},
  pages = {S133-S133},
  url = {://WOS:000347298600328},
  doi = {10.1016/j.nbt.2014.05.1941}
}
Pinar K and Melek O (2014), "Effect of Clostridium thermocellum activity on enzymatic hydrolysis of alkaline peroxide pretreated wheat straw", Research Journal of Biotechnology. Vol. 9(7), pp. 25-31.
Abstract: In this study, the microbial activity of Clostridium thermocellum on the hydrolysis of raw and pretreated wheat straw (WS) was investigated. The microbial activity was compared with the activity of enzyme mixture. It was found that alkaline peroxide pretreatment improves both microbial and the enzymatic digestibility of WS. Activity of C. thermocellum on the pretreated biomass is almost equal to the activity of 35 mu l/g enzyme which is equal to 5% of enzyme usage for complete saccharification of pretreated biomass. It was observed that enzymatic saccharification after C. thermocellum activity increased sugar release by 6% as compared to the sole enzymatic digestion.
BibTeX:
@article{Pinar2014,
  author = {Pinar, K. and Melek, O.},
  title = {Effect of Clostridium thermocellum activity on enzymatic hydrolysis of alkaline peroxide pretreated wheat straw},
  journal = {Research Journal of Biotechnology},
  year = {2014},
  volume = {9},
  number = {7},
  pages = {25--31},
  url = {://WOS:000338127600004}
}
Prodius D, Shah HS, Iqbal J, Macaeva A, Dimoglo A, Kostakis GE, Zill N, Macaev F and Powell AK (2014), "A novel example of double 6-exo-trig heterocyclization: nitrile conversion to new anticancer active (HeLa cells) primary amine ionic liquids", Chemical Communications. Vol. 50(38), pp. 4888-4890.
Abstract: Conversion of nitriles under mild conditions leads to a new class of primary amines, including room temperature ionic liquids, acting as efficient anticancer agents.
BibTeX:
@article{Prodius2014,
  author = {Prodius, D. and Shah, H. S. and Iqbal, J. and Macaeva, A. and Dimoglo, A. and Kostakis, G. E. and Zill, N. and Macaev, F. and Powell, A. K.},
  title = {A novel example of double 6-exo-trig heterocyclization: nitrile conversion to new anticancer active (HeLa cells) primary amine ionic liquids},
  journal = {Chemical Communications},
  year = {2014},
  volume = {50},
  number = {38},
  pages = {4888--4890},
  url = {://WOS:000334736900004},
  doi = {10.1039/c3cc49759c}
}
Senturk E, Ince M and Engin GO (2014), "The effect of shock loading on the performance of a thermophilic anaerobic contact reactor at constant organic loading rate", Journal of Environmental Health Science and Engineering. Vol. 12
Abstract: The influences of organic loading disturbances on the process performance of a thermophilic anaerobic contact reactor treating potato-processing wastewater were investigated. For this purpose, while the reactor was operated at steady state conditions with organic loading rate of 5.5 kg COD/m(3) . day, an instant acetate concentration increase (1 g/L) was introduced to the reactor. During the shock loading test of acetate, it was observed that the overall process performance was adversely affected by all the shock loading, however, the system reached steady state conditions less than 24 hours of operation indicating that thermophilic anaerobic contact reactor is resistant to shock loading and be capable of returning its normal conditions within a short time period.
BibTeX:
@article{Senturk2014,
  author = {Senturk, E. and Ince, M. and Engin, G. O.},
  title = {The effect of shock loading on the performance of a thermophilic anaerobic contact reactor at constant organic loading rate},
  journal = {Journal of Environmental Health Science and Engineering},
  year = {2014},
  volume = {12},
  url = {://WOS:000336678100001},
  doi = {10.1186/2052-336x-12-84}
}
Topkaya E, Konyar M, Yatmaz HC and Ozturk K (2014), "Pure ZnO and composite ZnO/TiO2 catalyst plates: A comparative study for the degradation of azo dye, pesticide and antibiotic in aqueous solutions", Journal of Colloid and Interface Science. Vol. 430, pp. 6-11.
Abstract: Photocatalytic degradations of azo dye (RR 180), pesticide (2,4-D) and antibiotic (enrofloxacin) in aqueous solutions were performed and compared by using pure ZnO and ZnO/TiO2 composite (at 1:1 ZnO to TiO2 mole ratio) catalysts in a self-supporting plate form. The plates were produced by tape casting of the constituent powder slurries and sintering at 600 degrees C. Photocatalytic degradations of these pollutants were carried out under UVA and UVC irradiations for 120 min. Maximum degradation was obtained for 2,4-D solution using pure ZnO plates under UVC. Due to the photolysis effect, UVC wavelength yielded higher efficiency values for all the chemicals than UVA. The discrepancy in the photocatalytic performances of the pure ZnO and the ZnO/TiO2 composite plates were not found to be significant. The plates were found to be effective for the consecutive degradation tests which indicated their potentiality in extended applications. (C) 2014 Elsevier Inc. All rights reserved.
BibTeX:
@article{Topkaya2014,
  author = {Topkaya, E. and Konyar, M. and Yatmaz, H. C. and Ozturk, K.},
  title = {Pure ZnO and composite ZnO/TiO2 catalyst plates: A comparative study for the degradation of azo dye, pesticide and antibiotic in aqueous solutions},
  journal = {Journal of Colloid and Interface Science},
  year = {2014},
  volume = {430},
  pages = {6--11},
  url = {://WOS:000348689100002},
  doi = {10.1016/j.jcis.2014.05.022}
}
Turkay O, Man H and Dimoglo A (2014), "Experimental and theoretical investigations of CuO-catalyzed ozonation of humic acid", Separation and Purification Technology. Vol. 134, pp. 110-116.
Abstract: In this study, the efficiency of copper oxide (CuO) as a catalyst in the ozonation process of humic acid (HA) was investigated in both experimental and theoretical respects. Ozonation and catalytic ozonation processes were conducted in a lab setting. HA concentration was determined by measurement of the surrogate organic parameters. The results show that the degradation of HA by catalytic ozonation in the presence of CuO was found to be much more effective than the ozonation process alone. The experimental data was verified by means of theoretical modeling. Density Function Theory (DFT) was used to calculate the decomposition of ozone in the catalytic processes. The reactions on the surface of metal oxides were evaluated with quantum-chemical calculations to explain the mechanisms of catalytic ozonation. Two models of adsorption were investigated: when only O-3 is attached to the surface and when O-3 and H2O are simultaneously adsorbed by the active center of catalyst. Each is a barrierless reaction, as follows from the calculations mentioned. The result of the first reaction is one oxygen molecule and atomic oxygen being adsorbed on the CuO surface. The second reaction's final products are O-2 and hydroxyl-radicals, which are adsorbed on the CuO surface. These particles behave as powerful oxidizing agents in the further reactions with HA. Comparison of the two mechanisms shows that the second reaction with the water molecule participation is preferable to the first one based on energy levels. (C) 2014 Elsevier B.V. All rights reserved.
BibTeX:
@article{Turkay2014,
  author = {Turkay, O. and Man, H. and Dimoglo, A.},
  title = {Experimental and theoretical investigations of CuO-catalyzed ozonation of humic acid},
  journal = {Separation and Purification Technology},
  year = {2014},
  volume = {134},
  pages = {110--116},
  url = {://WOS:000342532100013},
  doi = {10.1016/j.seppur.2014.07.040}
}
Ulu F, Barisci S, Kobya M, Sarkka H and Sillanpaa M (2014), "Removal of humic substances by electrocoagulation (EC) process and characterization of floc size growth mechanism under optimum conditions", Separation and Purification Technology. Vol. 133, pp. 246-253.
Abstract: The aim of this study was to evaluate the treatability of synthetically prepared humic acid solution by electrocoagulation (EC) process in batch mode using aluminum and iron electrodes. The effect of the main parameters pH, current density, and electrode type on natural organic matter (NOM) removal was investigated. Also, in order to understand the mechanism of floc formation and growth in electrocoagulation process, zeta potential and particle size measurements were done. The larger flocs and zeta potentials which closed to zero were observed at initial pH (pH(i)) 4 rather than pH(i) 5 and 6 for Al electrode. When zeta potential exhibited charge reversal, floc size reached to 5221 nm for pH; 4 at the current density of 1.2 mA/cm(2). The zeta potential remained negative over the whole pH range for Fe electrode. At pH(i) 4 and current density of 3 mA/cm(2), zeta potential value was -4.1 mV that indicate strong coagulation-flocculation. At these conditions, the maximum floc formation was 3042.3 nm. It can be concluded that, the removal of pollutant is due to charge neutralization and compression of double layer at lower initial pH value and sweeping and entrapment at higher pH. The removal efficiency of EC method was determined with respect to dissolved organic carbon (DOC) and UV/VIS absorbance at 254 and 436 nm reduction. Twenty-five minutes of process time with the aluminum electrode led to DOC removal of 87.5% with final DOC concentration of 2.01 mg/L and 91.1% UV-abs-254 removal was achieved after 2 min at pH(i) 4 and at current density of 1.2 mA/cm(2). The highest treatment efficiency for humic acid (HA) was 87% (DOCtreated 2.1 mg/L) at pH(i) 4 with iron electrodes. The short term best color removal (VIS absorbance at 436 nm) reduction performance was obtained with aluminum electrodes. (C) 2014 Elsevier B.V. All rights reserved.
BibTeX:
@article{Ulu2014,
  author = {Ulu, F. and Barisci, S. and Kobya, M. and Sarkka, H. and Sillanpaa, M.},
  title = {Removal of humic substances by electrocoagulation (EC) process and characterization of floc size growth mechanism under optimum conditions},
  journal = {Separation and Purification Technology},
  year = {2014},
  volume = {133},
  pages = {246--253},
  url = {://WOS:000341552900030},
  doi = {10.1016/j.seppur.2014.07.003}
}
Yilmaz O, Can ZS, Toroz I, Dogan O, Oncel S, Alp E, Dilek FB, Karanfil T and Yetis U (2014), "Use of theoretical waste inventories in planning and monitoring of hazardous waste management systems", Waste Management & Research. Vol. 32(8), pp. 763-771.
Abstract: Hazardous waste (HW) generation information is an absolute necessity for ensuring the proper planning, implementation, and monitoring of any waste management system. Unfortunately, environmental agencies in developing countries face difficulties in gathering data directly from the creators of such wastes. It is possible, however, to construct theoretical HW inventories using the waste generation factors (WGFs). The objective of this study was to develop a complete nationwide HW inventory of Turkey that relies on nation-specific WGFs to support management activities of the Turkish Ministry of Environment and Urbanization (MoEU). Inventory studies relied on WGFs from: (a) the literature and (b) field studies and analysis of waste declarations reflecting country-specific industrial practices. Moreover, new tools were introduced to the monitoring infrastructure of MoEU to obtain a comprehensive waste generation data set. Through field studies and a consideration of country specific conditions, it was possible to more thoroughly elucidate HW generation trends in Turkey, a method that was deemed superior to other alternatives. Declaration and literature based WGFs also proved most helpful in supplementing field observations that could not always be conducted. It was determined that these theoretical inventories could become valuable assets in supporting regulating agencies in developing countries for a more thorough implementation of HW management systems.
BibTeX:
@article{Yilmaz2014,
  author = {Yilmaz, O. and Can, Z. S. and Toroz, I. and Dogan, O. and Oncel, S. and Alp, E. and Dilek, F. B. and Karanfil, T. and Yetis, U.},
  title = {Use of theoretical waste inventories in planning and monitoring of hazardous waste management systems},
  journal = {Waste Management & Research},
  year = {2014},
  volume = {32},
  number = {8},
  pages = {763--771},
  url = {://WOS:000341183800010},
  doi = {10.1177/0734242x14542683}
}
Yucel Y, Demir C, Dizge N and Keskinler B (2014), "Methods for Lipase Immobilization and Their Use for Biodiesel Production from Vegetable Oil", Energy Sources Part a-Recovery Utilization and Environmental Effects. Vol. 36(11), pp. 1203-1211.
Abstract: In the present work, two different lipases (triacylglycerol hydrolase, EC 3.1.1.3), Lipozyme TL-100L and Novozyme 388, were immobilized onto three different low-cost supports using both adsorption and covalent method: celite 545, silica gel, and styrene-divinylbenzene copolymer. The maximum immobilization yield was obtained as 79.0% for Lipozyme TL-100L and the highest specific activity was 6.5 U/mg protein for Novozym 388. The properties of the support and immobilized derivatives were characterized by Fourier transform infrared spectroscopy. Maximum methyl esters yield was obtained as 98.3%. The lipases, which are immobilized by covalently, proved to be stable after even 10 repeated reuses.
BibTeX:
@article{Yucel2014,
  author = {Yucel, Y. and Demir, C. and Dizge, N. and Keskinler, B.},
  title = {Methods for Lipase Immobilization and Their Use for Biodiesel Production from Vegetable Oil},
  journal = {Energy Sources Part a-Recovery Utilization and Environmental Effects},
  year = {2014},
  volume = {36},
  number = {11},
  pages = {1203--1211},
  url = {://WOS:000333875400007},
  doi = {10.1080/15567036.2010.545805}
}
Akar N, Asar B, Dizge N and Koyuncu I (2013), "Investigation of characterization and biofouling properties of PES membrane containing selenium and copper nanoparticles", Journal of Membrane Science. Vol. 437, pp. 216-226.
Abstract: Selenium and copper nanoparticles exhibit superior antioxidant activity, unique properties, and great potential applications that make them very attractive for developing new composite materials. In this study, polyethersulfone (PES) ultrafiltration membrane was modified by dispersing nano-sized selenium (nSe) and copper (nCu) particles uniformly in a PES solution (18% polymer weight) and casted by a phase inversion process. Membranes with four different weight ratios of nSe and nCu to PES of 0.002, 0.010, 0.030, and 0.050 were tested. Selenium nanoparticles were prepared by the reduction of aqueous sodium selenite solution with freshly prepared glucose solution. The method was capable of producing spherical selenium nanoparticles in a size range of about 150-175 nm, under ambient conditions. The synthesized nanoparticles can be separated easily from the aqueous solutions by a high-speed centrifuge and can be re-dispersed in an aqueous medium by an ultra-sonicator. The effects of temperature, time, and stirring rate on the size of the selenium nanoparticles were studied. In addition, nanoscale particles of metallic copper clusters were prepared by sonochemical reduction of copper(II) hydrazine carboxylate Cu-(N2H3COO)(2) center dot 2H(2)O complex in an aqueous medium. Reduction process takes place under an argon atmosphere over a period of 2-3 h and the size of copper nanoparticles was about 90-105 nm. The synthesized selenium and copper nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and particle size distribution techniques. Moreover, Se/PES and Cu/PES blend membranes were also characterized using contact angle goniometer, scanning electron microscopy (SEM), and permeation tests. Anti-fouling performance was examined using activated sludge as a biological suspension. The protein rejection study was also carried out using the bovine serum albumin (BSA) solution. The morphology and permeation properties of the blend membranes were found to be dependent on the amounts of nanoparticles. Compared to neat PES membrane, the 0.05 Cu/PES membrane exhibited highest protein rejection ratio (86.3%). However, the Se/PES membranes showed better antifouling performance (lower flux decline). The blending membranes with nanoparticles are considered to be suitable for the prevention of biofouling. (c) 2013 Elsevier B.V. All rights reserved.
BibTeX:
@article{Akar2013,
  author = {Akar, N. and Asar, B. and Dizge, N. and Koyuncu, I.},
  title = {Investigation of characterization and biofouling properties of PES membrane containing selenium and copper nanoparticles},
  journal = {Journal of Membrane Science},
  year = {2013},
  volume = {437},
  pages = {216--226},
  url = {://WOS:000319117000026},
  doi = {10.1016/j.memsci.2013.02.012}
}
Akyol A, Can OT, Demirbas E and Kobya M (2013), "A comparative study of electrocoagulation and electro-Fenton for treatment of wastewater from liquid organic fertilizer plant", Separation and Purification Technology. Vol. 112, pp. 11-19.
Abstract: Treatments of the liquid organic fertilizer manufacturing wastewater (LFW) by electrocoagulation (EC) and electro-Fenton (EF) processes using iron electrodes were carried out in a batch electrolytic reactor. Effects of operating conditions such as current density and initial pH, for the EC process, and current density and initial H2O2 concentration for the EF process on removal efficiencies of total organic carbon (TOC), chemical oxygen demand (COD), color and total phosphate (TP) were investigated. Removal efficiencies of 79% for TOC, 83% for COD, 73% for TP and 95% for color from the EC process at the optimum operating conditions (50 A/m(2), 45 mm and pH(i) 6) and 87% for TOC, 91% for COD, 96% for TP and 99% for color from the EF process at the optimum operating conditions (50 A/m(2), 45 min, 25 mM H2O2 and pH(i) 3) respectively, were obtained. Operating costs for the EC and the EF processes were calculated as 0.74 and 1.23 (sic)/m(3). As a comparison from the obtained result, the EF process was found to be more effective than the EC process with respect to the removal efficiencies of COD, TOC and TP. However, the EF process was more expensive than the EC process. (C) 2013 Elsevier B.V. All rights reserved.
BibTeX:
@article{Akyol2013,
  author = {Akyol, A. and Can, O. T. and Demirbas, E. and Kobya, M.},
  title = {A comparative study of electrocoagulation and electro-Fenton for treatment of wastewater from liquid organic fertilizer plant},
  journal = {Separation and Purification Technology},
  year = {2013},
  volume = {112},
  pages = {11--19},
  url = {://WOS:000320295900002},
  doi = {10.1016/j.seppur.2013.03.036}
}
Aydiner C, Topcu S, Tortop C, Kuvvet F, Ekinci D, Dizge N and Keskinler B (2013), "A novel implementation of water recovery from whey: "forward-reverse osmosis" integrated membrane system", Desalination and Water Treatment. Vol. 51(4-6), pp. 786-799.
Abstract: As a result of its emerging contribution to water recovery and clean water production, forward osmosis (FO) in integrated membrane system has recently especially been preferred by research communities on membrane science and desalination technology. In this study, the effectiveness of FO reverse osmosis (RO) integrated membrane system in whey dewatering was investigated in laboratory scale experiments in which FO and RO were utilized for whey concentration and water recovery, respectively. FO experiments were carried out at different conditions of cross-flow rate, temperature, membrane kind, membrane orientation mode, and microfiltration (MF) pretreatment. A single-step RO system was applied for water recovery from the FO draw solution. In the FO process, about 1.6 L water of 3 L whey was withdrawn into 3 M NaCl draw solution during 6 h operating time, and a sufficiently high performance in whey concentration was obtained, with the solid content being increased from 6.8 to 14.3%. However, the process resulted in a high salt permeation into the whey, in addition to some soluble organics being permeated into the draw. RO process are operated with relatively low performances due to excessive salt concentration of the FO draw solutions, which indicates that there is a need for RO implementation in two or three sequential levels for achieving an absolute success in the water recovery from whey. Despite the fact that MF pretreatment to some extent decreased the FO performance, it could be used for directly productive activities intended to recover fats from whey. Results have proved that prior to whey powder production, the integrated system could be effectively employed for whey concentrations up to a solid content of 25-35%. Accordingly, FO-RO system can be utilized as a novel alternative in concentrating whey compared to ultrafiltration-RO combined system widely used worldwide. However, before practical implementation of the system, an optimization between alleviating the salt concentration in FO draw and multi-step RO implementation should have to be considered concurrently with the economics of the investment.
BibTeX:
@article{Aydiner2013,
  author = {Aydiner, C. and Topcu, S. and Tortop, C. and Kuvvet, F. and Ekinci, D. and Dizge, N. and Keskinler, B.},
  title = {A novel implementation of water recovery from whey: "forward-reverse osmosis" integrated membrane system},
  journal = {Desalination and Water Treatment},
  year = {2013},
  volume = {51},
  number = {4-6},
  pages = {786--799},
  url = {://WOS:000313794400015},
  doi = {10.1080/19443994.2012.693713}
}
Bayar S and Talinli I (2013), "Solidification/stabilization of hazardous waste sludge obtained from a chemical industry", Clean Technologies and Environmental Policy. Vol. 15(1), pp. 157-165.
Abstract: In this study, treatment sludge obtained from a chemical-metal finishing industry, which contained potentially toxic heavy metals and organics, was characterized, and the performance of the solidification/stabilization (S/S) of the sludge was discussed. The hazard characteristics of the waste were determined by means of extraction procedure toxicity test and DIN 38414-S4 Test, as defined in both Turkish and USEPA regulations. S/S studies were conducted using Portland cement to solidify the sludge containing high concentrations of total organic carbon, Cr, Cu, Hg, Ni, Pb, and Zn. The waste/binder ratios of 36 sludge specimens were kept between 0/100 and 40/100. The specimens were cured at room temperature for 7, 28, and 90 days. The compressive strengths of the specimens were measured to determine the feasibility of using solidified waste sludge as construction materials. The compressive strength values indicated that specimens could be potentially used as construction materials. The heavy metal and organic contents of the extracts of each specimen were detected in concentrations which were lower than the standard concentrations in EPTox and DIN 38414-S4 leaching procedures for the most part.
BibTeX:
@article{Bayar2013,
  author = {Bayar, S. and Talinli, I.},
  title = {Solidification/stabilization of hazardous waste sludge obtained from a chemical industry},
  journal = {Clean Technologies and Environmental Policy},
  year = {2013},
  volume = {15},
  number = {1},
  pages = {157--165},
  url = {://WOS:000314270100016},
  doi = {10.1007/s10098-012-0494-1}
}
Buhan E, Dogan HM, Buhan SD, Ozdemir S, Polat F and Dogan CN (2013), "Investigating phosphorus and turbidity removal efficiencies of main aquatic vegetation species in the Lower Kelkit Basin of Turkey", Turkish Journal of Botany. Vol. 37(4), pp. 744-752.
Abstract: In this study, we researched the main aquatic vegetation (AV) species and their orthophosphate and turbidity removal efficiencies in the Lower Kelkit Basin of Turkey. We chose an experimental area (1650 m(2)) in the field and determined orthophosphate (mg/L) and turbidity (NTU) variables at the charging and discharging points between November 2005 and March 2006. We also applied an experimental design including 9 treatments and 3 replications in aquarium conditions. Orthophosphate (mg/L) contents of each aquarium were measured at 6 time periods (initial measurement and days 1, 4, 9, 16, and 25). Ceratophyllum demersum L., Cladophora glomerata (L.) Kutzing, Lemna minor L., Myriophyllum spicatum L., Nasturtium officinale R.Br., Potamogeton pectinatus L., Typha angustifolia L., and Typha domingensis Pers. were determined as the main AV species in the study area. Paired samples t-test results showed that AV species significantly reduced both orthophosphate and turbidity in the field conditions. Mean daily orthophosphate and turbidity removal capacities of the wetland were determined as 0.13 mg/L and 2.82 NTU, respectively. Analysis of variance and Duncan's honestly significant difference results indicated that orthophosphate uptake efficiencies of the plant species vary from 0.34 mg/L to 0.04 mg/L, and Lemna minor L. and Ceratophyllum demersum L. are the most efficient species in aquarium conditions.
BibTeX:
@article{Buhan2013,
  author = {Buhan, E. and Dogan, H. M. and Buhan, S. D. and Ozdemir, S. and Polat, F. and Dogan, C. N.},
  title = {Investigating phosphorus and turbidity removal efficiencies of main aquatic vegetation species in the Lower Kelkit Basin of Turkey},
  journal = {Turkish Journal of Botany},
  year = {2013},
  volume = {37},
  number = {4},
  pages = {744--752},
  url = {://WOS:000322924800016},
  doi = {10.3906/bot-1209-21}
}
Copur Y, Tozluoglu A and Ozkan M (2013), "Evaluating pretreatment techniques for converting hazelnut husks to bioethanol", Bioresource Technology. Vol. 129, pp. 182-190.
Abstract: This study examined the suitability of husk waste for bioethanol production and compared pretreatment techniques with regard to their efficiencies. Results showed that 4% NaBH4 (90 mm) delignified the highest amount of lignin (49.1%) from the structure. The highest xylan solubility (77.9%) was observed when samples were treated with 4% NaOH for 90 min. Pretreatment with NaOH and NaBH4, compared to H2O2 and H2SO4, resulted in selective delignification. The highest glucan to glucose conversion (74.4%) and the highest ethanol yield (52.6 g/kg husks) were observed for samples treated with 2% NaOH for 90 min. (C) 2012 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Copur2013,
  author = {Copur, Y. and Tozluoglu, A. and Ozkan, M.},
  title = {Evaluating pretreatment techniques for converting hazelnut husks to bioethanol},
  journal = {Bioresource Technology},
  year = {2013},
  volume = {129},
  pages = {182--190},
  url = {://WOS:000324566000026},
  doi = {10.1016/j.biortech.2012.11.058}
}
Dizge N, Koseoglu-Imer DY, Karagunduz A and Keskinler B (2013), "Effect of sludge retention time on membrane bio-fouling using different type and pore size of membranes in a submerged membrane bioreactor", Water Science and Technology. Vol. 67(3), pp. 604-611.
Abstract: The objective of this study was to investigate the influence of sludge retention time (SRT) on membrane bio-fouling. An activated sludge reactor was operated at three different SRTs (10, 30, and 50 days). Submerged membrane experiments were performed when the mixed liquor suspended solids (MLSS) concentration reached the steady state conditions. MLSS concentrations reached the steady state at 3,109+/-194, 6,209+/-123 and 6,609+/-280 mg/L for SRTs of 10, 30 and 50 days, respectively. The total soluble microbial products (SMP) were 20.1+/-3.7, 16.2+/-7.2 and 28.2+/-8.4 mg/L at SRTs of 10, 30, and 50 days, respectively. The carbohydrate concentration in the supernatant was about two times more for SRT of 10 days than that for 50 days. The total amount of extracellular polymeric substances (EPS) extracted from the flocs were approximately 74.9+/-11.9, 67.8+/-15.0 and 67.5+/-17.4 mg/g MLSS at three SRTs (10, 30, and 50 days) under the same organic loading rate. The viscosity of the biomass increased with the increasing SRT. The results of flux stepping tests showed that the membrane fouling at SRT 10 days was always higher than that of 30 and 50 days. Four different microfiltration membranes (cellulose acetate, polyethersulfone, mixed ester, and polycarbonate) with three different pore sizes (0.45, 0.22, 0.10 mu m) were tested. Filtration resistances were determined for each membrane. Cake resistance was observed to be the most significant fouling mechanism for all membranes.
BibTeX:
@article{Dizge2013,
  author = {Dizge, N. and Koseoglu-Imer, D. Y. and Karagunduz, A. and Keskinler, B.},
  title = {Effect of sludge retention time on membrane bio-fouling using different type and pore size of membranes in a submerged membrane bioreactor},
  journal = {Water Science and Technology},
  year = {2013},
  volume = {67},
  number = {3},
  pages = {604--611},
  url = {://WOS:000315194500019},
  doi = {10.2166/wst.2012.607}
}
Durak SG, Imer DYK, Demirkol GT, Ormanci T, Armagan B and Tufekci N (2013), "Influence of ageing on the catalytic activity of MnO2 sludge for oxidation of Mn(II)", Desalination and Water Treatment. Vol. 51(28-30), pp. 5692-5700.
Abstract: Manganese can be present in natural water in concentrations exceeding 10mg/l. If not treated well, Mn(II) ions can easily escape through the water treatment systems. Mn(II) in the distribution systems could form manganese dioxide, which is insoluble in water, causing several problems such as water discoloration, turbidity, metallic taste, odour, corrosion and biofouling. Oxidation is a common method for Mn(II) removal. Oxidation process can become more efficient with catalytic effects of several substances. High Mn(IV) concentrations can be maintained only by sludge recycle which eventually leads to sludge ages as high as 10days. The aim of this study was to determine whether ageing of MnO2 sludge affects its catalytic effect on the oxidation of manganese by aeration. In order to reach this aim, five different groups of experiments were carried out by MnO2 sludge aged for a period of 0-10days. It has been demonstrated that the catalytic effect of MnO2 sludge on the oxidation of manganese, contrary to what is commonly expected, aeration increases with increasing sludge age. It has been concluded that, catalytic oxidation rate constant, k(cat) obtained from the batch systems can safely be used in design of continuous flow Mn(II) oxidation reactors with sludge recycle. As a result, the catalytic effect of MnO2 sludge on the Mn(II) oxidation by aeration increases with increasing sludge age up to approximately fourth day.
BibTeX:
@article{Durak2013,
  author = {Durak, S. G. and Imer, D. Y. K. and Demirkol, G. T. and Ormanci, T. and Armagan, B. and Tufekci, N.},
  title = {Influence of ageing on the catalytic activity of MnO2 sludge for oxidation of Mn(II)},
  journal = {Desalination and Water Treatment},
  year = {2013},
  volume = {51},
  number = {28-30},
  pages = {5692--5700},
  url = {://WOS:000323194300034},
  doi = {10.1080/19443994.2013.769667}
}
Eyvaz M, Akgiray O and Yuksel E (2013), "An experimental investigation on the hydraulic behavior of declining rate filtration", Desalination and Water Treatment. Vol. 51(31-33), pp. 6137-6147.
Abstract: Hydraulic behavior of declining rate filtration (DRF) was investigated by means of pilot-scale experiments. A bank of four declining rate filters was constructed and operated. The common water level in the filters, individual filter velocities, and head losses in the filters were carefully monitored and recorded as functions of time. Many of the previous studies on DRF employed either a single average filtration velocity or a single coagulant dosage. In this study, however, filter runs were repeated treating the same water at several different filtration rates and coagulant dosages. Using such an experimental matrix of several different rates and coagulant dosages allowed an evaluation of the behavior of the declining rate filtration system under different operating conditions and the effects of the mentioned variables on various hydraulic characteristics of the DRF system. The validity of certain simplifying assumptions used in design calculations was also tested in these experiments. It is believed that the new data presented herein will lead to a better understanding of DRF.
BibTeX:
@article{Eyvaz2013,
  author = {Eyvaz, M. and Akgiray, O. and Yuksel, E.},
  title = {An experimental investigation on the hydraulic behavior of declining rate filtration},
  journal = {Desalination and Water Treatment},
  year = {2013},
  volume = {51},
  number = {31-33},
  pages = {6137--6147},
  url = {://WOS:000325921700026},
  doi = {10.1080/19443994.2013.763736}
}
Gengec E and Kobya M (2013), "Treatment of Baker's Yeast Wastewater by Electrocoagulation and Evaluation of Molecular Weight Distribution with HPSEC", Separation Science and Technology. Vol. 48(18), pp. 2880-2889.
Abstract: In the present paper, the molecular weight distributions (MWDs) of Baker's yeast wastewater (BYW) during electrocoagulation (EC) are investigated by High Performance Size Exclusion Chromatography (HPSEC) with ultraviolet diode array (DAD) and refractive index detectors (RID). The results of this study show that using DAD and RID in HPSEC are quite useful in order to reveal changes in MWDs of all components (whether UV-Vis absorption or not) by RID, and colored (strongly absorb UV-Vis radiation) by DAD. Molecular Weights (MW) of components are varied in a wide range of 92.0 Da - 2.1x10(6) Da. The high molecular weight components (HMWCs) and low molecular weight components (LMWCs) are present in low concentrations but they contribute high amount to color intensity (total contribution of two fractions are about 80%) whereas the intermediate molecular weight components (IMWCs) have high concentration with low amount to color intensity. The optimum operating conditions for the removal of color and COD are found as 86% and 43% at 80 A/m(2), pH(i) 4 and 20min in EC process with Al electrode. The EC process remove the HMWCs more efficiently; thus color removal efficiencies are high with respect to COD and TOC removal efficiencies during EC.
BibTeX:
@article{Gengec2013,
  author = {Gengec, E. and Kobya, M.},
  title = {Treatment of Baker's Yeast Wastewater by Electrocoagulation and Evaluation of Molecular Weight Distribution with HPSEC},
  journal = {Separation Science and Technology},
  year = {2013},
  volume = {48},
  number = {18},
  pages = {2880--2889},
  url = {://WOS:000326674200019},
  doi = {10.1080/01496395.2013.804087}
}
Ince M, Senturk E, Engin GO and Keskinler B (2013), "Landfill Leachate Treatment in Jet-Loop Membrane Bioreactor Operated Under Different Organic Loading Rates", International Journal of Environmental Research. Vol. 7(3), pp. 827-834.
Abstract: Since treatment of landfill leachate is quite complicated, there is a need to develop a system that is capable of providing high treatment efficiencies. In this study, the treatment performance of a jet - loop membrane bioreactor (JLMB) operated at different organic loading rates was investigated by observing the changes in Chemical Oxygen Demand (COD), Total Kjehidahl Nitrogen (TKN) and Total Ammonia (NH3) concentrations. The same COD removal rates (83%) were observed at all the studied loading rates, and it should be noted that the biodegradable part of the leachate was removed completely. It was also observed that the NH4 - N / TKN ratios, which were found to be approximately 0.9, did not change throughout the study. However, further treatment technologies, such as reverse osmosis, nanofiltration or ion - exchange, should be employed for the complete removal of inert COD and NH3 in order to meet related discharge limits.
BibTeX:
@article{Ince2013,
  author = {Ince, M. and Senturk, E. and Engin, G. O. and Keskinler, B.},
  title = {Landfill Leachate Treatment in Jet-Loop Membrane Bioreactor Operated Under Different Organic Loading Rates},
  journal = {International Journal of Environmental Research},
  year = {2013},
  volume = {7},
  number = {3},
  pages = {827--834},
  url = {://WOS:000319952600021}
}
Ince M (2013), "Treatment of Manganese-Phosphate Coating Wastewater by Electrocoagulation", Separation Science and Technology. Vol. 48(3), pp. 515-522.
Abstract: The effective performance of the electrocoagulation (EC) technique in removing manganese, phosphate, and iron from rinse water from a Mn-PO4 (MPO) coating plant was investigated using sacrificial aluminum electrodes in original pH. It was found that an increase in the current enhanced the speed of the removal significantly. However, simultaneous increase of electrode and energy consumption was observed. The optimum current density allowing the quickest treatment with a low cost was found to be 20 A m-2. In 20 A m-2, the process produces a removal capacity of 97.95% of manganese, 99.96% of phosphate, and 99.78% of iron, just after 30 min. The energy and electrode consumptions were determined to be 2.294 kWh m-3 and 5.584 kg m-3 of treated rinse water at the end of process, respectively. Additionally, three different electrode connection modes (MP-P, MP-S, and BP-S) were examined in choosing a better alternative in order to intensify the performance of the process. MP-P electrode connection mode was found to be a suitable configuration in consideration of removal efficiency, energy, and electrode consumptions.
BibTeX:
@article{Ince2013a,
  author = {Ince, M.},
  title = {Treatment of Manganese-Phosphate Coating Wastewater by Electrocoagulation},
  journal = {Separation Science and Technology},
  year = {2013},
  volume = {48},
  number = {3},
  pages = {515--522},
  url = {://WOS:000313681000017},
  doi = {10.1080/01496395.2012.690125}
}
Insel G, Dagdar M, Dogruel S, Dizge N, Cokgor EU and Keskinler B (2013), "Biodegradation characteristics and size fractionation of landfill leachate for integrated membrane treatment", Journal of Hazardous Materials. Vol. 260, pp. 825-832.
Abstract: The fate of organics and nitrogen during the biological treatment with MBR and subsequent membrane filtration processes (nano filtration, NE; reverse osmosis, RO) were investigated for a landfill leachate. The chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN) removal performances of membrane bioreactor (MBR) were obtained to be around 89% and 85%, respectively. The effluent COD of MBR was measured to be 1935 mg/L (30 kDa) which is much lower than experimentally determined soluble inert COD of 3200 mg/L using 0.45 mu m filter. The readily and slowly biodegradable COD fractions were estimated to be 17% and 52% of raw influent COD, respectively. The respirometry based modeling test performed on raw leachate exhibited much slower degradation kinetics compared to municipal wastewater. A unique subset of model parameters was extracted from batch respirometry by using acclimated MBR sludge. The sequential ultrafiltration (UF) experiments (particle size distribution, PSD) revealed that most of the organics was below 2 nm filter mesh size. In addition, NF/RO post treatment after MBR system was required to increase COD and total nitrogen (TN) removal performances up to 99%. Relatively lower salt rejection rates around 94% was obtained for RO system as a post treatment of MBR system. (C) 2013 Elsevier B.V. All rights reserved.
BibTeX:
@article{Insel2013,
  author = {Insel, G. and Dagdar, M. and Dogruel, S. and Dizge, N. and Cokgor, E. U. and Keskinler, B.},
  title = {Biodegradation characteristics and size fractionation of landfill leachate for integrated membrane treatment},
  journal = {Journal of Hazardous Materials},
  year = {2013},
  volume = {260},
  pages = {825--832},
  url = {://WOS:000324563500100},
  doi = {10.1016/j.jhazmat.2013.06.037}
}
Kara S, Gurbulak E, Eyvaz M and Yuksel E (2013), "Treatment of winery wastewater by electrocoagulation process", Desalination and Water Treatment. Vol. 51(28-30), pp. 5421-5429.
Abstract: Winery wastewater treatment by electrocoagulation (EC) process using aluminum (Al) and iron (Fe) electrodes was investigated. The effects of operational parameters such as initial pH, current density and electrolysis time were investigated separately. Chemical oxygen demand (COD), turbidity and color were used to measure the treatment efficiency. Electrode consumptions were calculated per m(3) of wastewater. Amount of sludge produced by EC was also reported per m(3) of wastewater. The optimum operating conditions were defined due to the initial pH, applied current density and operating time for Fe and Al electrodes. Maximum removal efficiencies were found at pH 7 for Fe electrode and pH 5.2 for Al electrode with current density of 300A/m(2) for both electrodes and with an operating time of 90min and 120min for Fe and Al electrodes, respectively. The removal efficiencies were found as 46.6% (COD), 80.3% (color) and 92.3% (turbidity) for Fe electrode while they were 48.5% for COD, 97.2% for color and 98.6% for turbidity when Al electrodes were used. Finally, the results were compared with various food and beverage industry wastewaters treated by EC process reported in the literature.
BibTeX:
@article{Kara2013,
  author = {Kara, S. and Gurbulak, E. and Eyvaz, M. and Yuksel, E.},
  title = {Treatment of winery wastewater by electrocoagulation process},
  journal = {Desalination and Water Treatment},
  year = {2013},
  volume = {51},
  number = {28-30},
  pages = {5421--5429},
  url = {://WOS:000323194300005},
  doi = {10.1080/19443994.2013.770223}
}
Kara S (2013), "Treatment of transport container washing wastewater by electrocoagulation", Environmental Progress & Sustainable Energy. Vol. 32(2), pp. 249-256.
Abstract: In this study, the effects of operational parameters such as initial pH, current density, and electrolysis time on the treatment of transport container washing wastewater by electrocoagulation (EC) with aluminum (Al) and iron (Fe) electrodes were investigated separately. Chemical oxygen demand (COD), turbidity and color were used to measure the treatment efficiency. Energy consumptions were calculated per cubic meter of wastewater. Amount of sludge produced after EC was also reported per cubic meter of wastewater. Different direct and indirect cost items including energy, sacrificial electrodes, labor, sludge handling and disposal, maintenance, and depreciation costs have been considered in the calculation of the total operating cost, and it was calculated as per cubic meter of wastewater and per kilograms of COD removed. The total operating costs were acquired as 11.2 $m3 with 79.45% of COD, 99.71% of color, and 99.45% of turbidity removal efficiencies by Fe electrodes and 23.89 $ m3 with 76.31% of COD, 99.05% of color, and 99.77% of turbidity removal efficiencies by Al electrodes under the optimum parameters in this study. In addition, the optimum operating times were found as 30 min for Fe electrodes and 60 min for Al electrodes. (c) 2012 American Institute of Chemical Engineers Environ Prog, 32: 249-256, 2013
BibTeX:
@article{Kara2013a,
  author = {Kara, S.},
  title = {Treatment of transport container washing wastewater by electrocoagulation},
  journal = {Environmental Progress & Sustainable Energy},
  year = {2013},
  volume = {32},
  number = {2},
  pages = {249--256},
  url = {://WOS:000317851600012},
  doi = {10.1002/ep.11616}
}
Karagoz P and Ozkan M (2013), "Optimization of dilute acid and alkaline peroxide pretreatment to enhance ethanol production from wheat straw", Turkish Journal of Biochemistry-Turk Biyokimya Dergisi. Vol. 38(4), pp. 457-467.
Abstract: Objective: The main purpose of this study was to determine the optimal pretreatment process conditions for wheat straw to maximize the overall ethanol yield. Methods: The effects of pretreatment conditions for dilute acid and alkaline peroxide pretreatment were investigated using Response Surface Methodology (RSM). Co-fermentation with S. cerevisiae and P. stipitis was employed to produce ethanol from pretreated solids. Cellulose and xylan composition of wheat straw, degradability of these compounds, as well as ethanol production, were monitored at different conditions. Results: 0.5% H2SO4 concentration, 15% solid loading, and particle size between 0.75-0.9 mm ( 20 mesh) was predicted to be optimal by RSM for dilute acid pretreatment and experiment performed at that condition resulted in overall ethanol yield of 12.95%. The maximum overall ethanol yield determined for alkaline peroxide pretreatment is 18.23% and can be achieved when the pretreatment were done with 0.875% H2O2 at 35 degrees C for 1 h. Experimental results agreed with the responses. Conclusion: Alkaline peroxide pretreatment of wheat straw was found to be more effective than dilute acid pretreatment for enhancing bioethanol production from wheat straw by co-fermentation.
BibTeX:
@article{Karagoz2013,
  author = {Karagoz, P. and Ozkan, M.},
  title = {Optimization of dilute acid and alkaline peroxide pretreatment to enhance ethanol production from wheat straw},
  journal = {Turkish Journal of Biochemistry-Turk Biyokimya Dergisi},
  year = {2013},
  volume = {38},
  number = {4},
  pages = {457--467},
  url = {://WOS:000329577500014},
  doi = {10.5505/tjb.2013.57431}
}
Kaya Y, Ersan G, Vergili I, Gonder ZB, Yilmaz G, Dizge N and Aydiner C (2013), "The treatment of pharmaceutical wastewater using in a submerged membrane bioreactor under different sludge retention times", Journal of Membrane Science. Vol. 442, pp. 72-82.
Abstract: The performance of a lab-scale submerged membrane bioreactor system (SMBR) for treating a process wastewater containing the pharmaceutical active compound (PhAc) etodolac with four different microfiltration (MF) membranes (MP005, MV02, CA, and MCE) was investigated at three different sludge retention times (SRTs) under constant pressure. In the first phase of the study, the continuous bioreactor system was operated at SRTs of 15 and 30 days and without sludge wasting (WSW). After steady state conditions were reached, the SMBR process was started as the second phase. Short-term filtration (24 h) tests were conducted for each SRT. When the SRTs were increased, both permeate volumes and steady-state flux values increased. The best etodolac removals were obtained in case of WSW for both bioreactor system and SMBR. The etodolac removals achieved by the different membranes for the period WSW were observed in the following order: MV02 = MP005 > CA = MCE. In addition, the chemical oxygen demand (COD) removal efficiencies for bioreactor system and SMBR were approximately 80 +/- 2% and 86 +/- 2%, respectively, at all SRTs. The COD removals at each of the three SRTs were similar for all of the membranes. Extracellular polymeric substances (EPSs) and soluble microbial products (SMPs) were analyzed as fouling control factors. Increasing the SRT caused increases in sludge concentrations in the SMBR as well as in increased etodolac removal, while EPS and SMP protein and carbohydrate concentrations decreased. Fouling on the pores and surfaces of the membranes were characterized using a Scanning Electron Microscope (SEM), an Atomic Force Microscope (AFM), a Fourier transform infrared spectroscopy (FT-IR), and contact angle measurements. The resistance in series model was used to evaluate the flux decline caused by the gel layer, cake resistance, and internal pore blocking in the MF membranes at the three different SRTs. (C) 2013 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kaya2013,
  author = {Kaya, Y. and Ersan, G. and Vergili, I. and Gonder, Z. B. and Yilmaz, G. and Dizge, N. and Aydiner, C.},
  title = {The treatment of pharmaceutical wastewater using in a submerged membrane bioreactor under different sludge retention times},
  journal = {Journal of Membrane Science},
  year = {2013},
  volume = {442},
  pages = {72--82},
  url = {://WOS:000320695100010},
  doi = {10.1016/j.memsci.2013.03.059}
}
Kim K, Kim YS and Gurol MD (2013), "DNAPL TCE Oxidation with Permanganate: Influence of the Phase Transfer Catalyst Pentyltriphenylphosphonium", Water Air and Soil Pollution. Vol. 224(10)
Abstract: Dense nonaqueous phase (DNAPL) trichloroethylene (TCE) degradation by potassium permanganate (KMnO4) was investigated in the presence of the cationic surfactant pentyltriphenylphosphonium (PTPP) bromide, acting as a phase transfer catalyst. Series of batch tests were performed in 5.0-mL conical vials containing Milli-Q water and 1.0mM DNAPL TCE with initial permanganate concentrations ([MnO4(-)]0) of 1.0, 2.0, 3.0, and 5.0 mM, adding PTPP (0, 10, and 20 mol% of permanganate, respectively). Chloride ion (Cl-) and MnO4(-) in water samples were analyzed to observe MnO4(-) consumption and TCE degradation over the elapsed time (0 to 90 min). The calculated values of pseudo first-order rate constants for MnO4(-) consumption indicated that the rate of MnO4(-) depletion increased with higher mole percent PTPP. At experimental conditions of 1.0 and 2.0 mM [MnO4(-)]0, analyses of Cl- concentration showed that higher mole percent of PTPP induced greater Cl- release, indicating faster TCE oxidation. On the other hand, for 3.0 and 5.0 mM [MnO4(-)] 0, the concentration of Cl- was lower with the presence of PTPP. This result indicated that MnO4(-) had migrated further into the inner space of DNAPL, and consequently, the Cl- took a longer time to diffuse from DNAPL to an aqueous phase.
BibTeX:
@article{Kim2013,
  author = {Kim, K. and Kim, Y. S. and Gurol, M. D.},
  title = {DNAPL TCE Oxidation with Permanganate: Influence of the Phase Transfer Catalyst Pentyltriphenylphosphonium},
  journal = {Water Air and Soil Pollution},
  year = {2013},
  volume = {224},
  number = {10},
  url = {://WOS:000326051700015},
  doi = {10.1007/s11270-013-1735-6}
}
Kiran I, Bektas N, Yatmaz HC and Tekbas M (2013), "Photocatalytic Fenton oxidation of sodium dodecyl sulfate solution using iron-modified zeolite catalyst", Desalination and Water Treatment. Vol. 51(28-30), pp. 5768-5775.
Abstract: The heterogeneous photo-Fenton oxidation of sodium dodecyl sulfate (SDS) solutions was investigated in a quartz batch reactor using an artificial UV light source. Fe-modified zeolite was used as a heterogeneous catalyst in the process. The effect of various process variables on SDS removal performance was evaluated by examining temperature, pH, H2O2 dosage, catalyst loading, initial SDS concentration and light intensity. The optimal operational parameters were found as follows: temperature 35 degrees C, solution pH 7.5, 15mmol H2O2 dosage, and 1g/L catalyst loading. Stability and the reuse of the catalyst were also tested. Comparison with homogenous photo-Fenton process was also performed by analyzing SDS removal rate. Kinetic investigation of removal process based on different kinetic models was evaluated. The results showed that the first-order kinetic model was in good correlation with experimental data.
BibTeX:
@article{Kiran2013,
  author = {Kiran, I. and Bektas, N. and Yatmaz, H. C. and Tekbas, M.},
  title = {Photocatalytic Fenton oxidation of sodium dodecyl sulfate solution using iron-modified zeolite catalyst},
  journal = {Desalination and Water Treatment},
  year = {2013},
  volume = {51},
  number = {28-30},
  pages = {5768--5775},
  url = {://WOS:000323194300043},
  doi = {10.1080/19443994.2012.759517}
}
Kobya M, Demirbas E, Gebologlu U, Oncel MS and Yildirim Y (2013), "Optimization of arsenic removal from drinking water by electrocoagulation batch process using response surface methodology", Desalination and Water Treatment. Vol. 51(34-36), pp. 6676-6687.
Abstract: In this investigation, arsenic removal from drinking water using electrocoagulation (EC) in a batch mode was studied by response surface methodology (RSM). The RSM was applied to optimize the operating variables viz. current density (CD, A/m(2)), operating time (t(EC), min) and arsenic concentration (C-o, g/L) on arsenic removal in the EC process using iron electrodes. The combined effects of these variables were analyzed by the RSM using quadratic model for predicting the highest removal efficiency of arsenic from drinking water. The proposed model fitted very well with the experimental data. R-2 adjusted correlation coefficients (AdjR(2): 0.93) for arsenic removal efficiency showed a high significance of the model. The model predicted for a maximum removal of arsenic at the optimum operating conditions (112.3g/L, 5.64A/m(2) and 5min) after the EC process was 93.86% which corresponded to effluent arsenic concentration of 6.9g/L. The minimum operating cost (OC) of the EC process was 0.0664Euro/m(3). This study clearly showed that the RSM was one of the suitable methods for the EC process to optimize the best operating conditions for target value of effluent arsenic concentration (<10g/L) while keeping the OC (energy and electrode consumptions) to minimal.
BibTeX:
@article{Kobya2013,
  author = {Kobya, M. and Demirbas, E. and Gebologlu, U. and Oncel, M. S. and Yildirim, Y.},
  title = {Optimization of arsenic removal from drinking water by electrocoagulation batch process using response surface methodology},
  journal = {Desalination and Water Treatment},
  year = {2013},
  volume = {51},
  number = {34-36},
  pages = {6676--6687},
  url = {://WOS:000326371800026},
  doi = {10.1080/19443994.2013.769700}
}
Koseoglu-Imer DY (2013), "The determination of performances of polysulfone (PS) ultrafiltration membranes fabricated at different evaporation temperatures for the pretreatment of textile wastewater", Desalination. Vol. 316, pp. 110-119.
Abstract: The effects of evaporation temperature on properties and filtration performances of polysulfone membrane were investigated with a series of experiments. Membranes were fabricated by phase inversion process at five different evaporation temperatures (25 +/- 0.4, 35 +/- 0.6, 45 +/- 0.5, 55 +/- 0.5 and 65 +/- 0.6 degrees C). The resulted membranes were characterized by water permeability, MWCO (molecular weight cut-off), AFM, porosity, contact angle and SEM analyses and tested for filtration performances by using a model dye solution (reactive orange 16-RO16) and a real dye-bath textile wastewater. The pore size and density onto the membrane surface become smaller and the surface roughness, porosity, permeability and MWCO values of membranes considerably decreased with the increasing of evaporation temperature. At the pretreatment filtration experiments, the flux values of membranes decreased largely with the increase of the evaporation temperature while the removal efficiencies for color, COD and conductivity parameters increased. At the membrane fouling analysis, the flux reduction ratios (FRR), the filtration (R-t) and fouling (R-f) resistances and the reusable performances of membrane changed directly proportional with roughness, porosity and pore size characteristics of membranes. At the nanofiltration step (NF-270 membrane), the moderate color, chemical oxygen demand (COD) and conductivity removal were showed at permeate of PS-65 membrane (the membrane fabricated at 65 +/- 0.6 degrees C). (C) 2013 Elsevier B.V. All rights reserved.
BibTeX:
@article{Koseoglu-Imer2013,
  author = {Koseoglu-Imer, D. Y.},
  title = {The determination of performances of polysulfone (PS) ultrafiltration membranes fabricated at different evaporation temperatures for the pretreatment of textile wastewater},
  journal = {Desalination},
  year = {2013},
  volume = {316},
  pages = {110--119},
  url = {://WOS:000317945300014},
  doi = {10.1016/j.desal.2013.02.011}
}
Koseoglu-Imer DY, Kose B, Altinbas M and Koyuncu I (2013), "The production of polysulfone (PS) membrane with silver nanoparticles (AgNP): Physical properties, filtration performances, and biofouling resistances of membranes", Journal of Membrane Science. Vol. 428, pp. 620-628.
Abstract: The polysulfone (PS) membranes were prepared by adding different amounts of silver nanoparticle-AgNP (0-1 wt%) into the dope solution. The bare PS and AgNP entrapped PS membranes (AgNP-PS composite membrane) were tested for physical properties with water permeability, MWCO (molecular weight cut-off), AFM, contact angle and SEM analyses, filtration performances by using the model protein (BSA) and carbohydrate (dextran) solutions and biofouling resistances by using a real activated sludge. AgNP addition improved the protein and carbohydrate filtration performances of bare PS membrane. The results of biofouling experiments showed the AgNP-PS composite membranes having lower absorptive and pore fouling values than bare PS membrane. The ionic silver loss from membrane during pure water filtration was measured using inductive-coupled plasma spectrometer (ICP) and the results showed the minimum silver loss from the composite membranes. The results of disk diffusion test showed that the composite AgNP-PS membranes decreased the growth of bacterial colonies. However PCR-DGEE technique showed that there were not significant differences in microbial community population density along the bare and composite membranes. (C) 2012 Elsevier B.V. All rights reserved.
BibTeX:
@article{Koseoglu-Imer2013a,
  author = {Koseoglu-Imer, D. Y. and Kose, B. and Altinbas, M. and Koyuncu, I.},
  title = {The production of polysulfone (PS) membrane with silver nanoparticles (AgNP): Physical properties, filtration performances, and biofouling resistances of membranes},
  journal = {Journal of Membrane Science},
  year = {2013},
  volume = {428},
  pages = {620--628},
  url = {://WOS:000313653700069},
  doi = {10.1016/j.memsci.2012.10.046}
}
Koseoglu-Imer DY and Keskinler B (2013), "Immobilization of Acidithiobacillus ferrooxidans on sulfonated microporous poly(styrene-divinylbenzene) copolymer with granulated activated carbon and its use in bio-oxidation of ferrous iron", Materials Science & Engineering C-Materials for Biological Applications. Vol. 33(1), pp. 53-58.
Abstract: The immobilization efficiencies of Acidithiobacillus ferrooxidans cells on different immobilization matrices were investigated for biooxidation of ferrous iron (Fe2+) to ferric iron (Fe3+). Six different matrices were used such as the polyurethane foam (PUF), granular activated carbon (GAC), raw poly(styrene-divinylbenzene) copolymer (rawSDVB), raw poly(styrene-divinylbenzene) copolymer with granular activated carbon (rawSDVB-GAC), sulfonated poly(styrene-divinylbenzene) copolymer (sulfSDVB) and sulfonated poly(styrene-divinylbenzene) copolymer with granular activated carbon (sulfSDVB-GAC). The sulfSDVB-GAC polymer showed the best performance for Fe2+ biooxidation. It was used at packed-bed bioreactor and the kinetic parameters were obtained. The highest Fe2+ biooxidation rate (R) was found to be 4.02 g/L h at the true dilution rate (D-t) of 2.47 1/h and hydraulic retention time (tau) of 0.4 h. The sulfSDVB-GAC polymer was used for the first time as immobilization material for A. ferrooxidans for Fe2+ biooxidation. (c) 2012 Elsevier B.V. All rights reserved.
BibTeX:
@article{Koseoglu-Imer2013b,
  author = {Koseoglu-Imer, D. Y. and Keskinler, B.},
  title = {Immobilization of Acidithiobacillus ferrooxidans on sulfonated microporous poly(styrene-divinylbenzene) copolymer with granulated activated carbon and its use in bio-oxidation of ferrous iron},
  journal = {Materials Science & Engineering C-Materials for Biological Applications},
  year = {2013},
  volume = {33},
  number = {1},
  pages = {53--58},
  url = {://WOS:000313155500007},
  doi = {10.1016/j.msec.2012.08.003}
}
Ozoner SK, Erhan E, Yilmaz F, Ergenekon P and Anil I (2013), "Electrochemical biosensor for detection of formaldehyde in rain water", Journal of Chemical Technology and Biotechnology. Vol. 88(4), pp. 727-732.
Abstract: BACKGROUD: This study describes the construction of an electrochemical formaldehyde biosensor based on poly(glycidyl methacrylate-co-3-methylthienyl methacrylate)/formaldehyde dehydrogenase/polypyrrole [poly(GMA-co-MTM)/FDH/PPy] composite film electrode. Formaldehyde dehydrogenase (FDH) was chemically immobilized via the epoxy groups of the glycidyl methacrylate (GMA) side chain of the polymer. Formaldehyde measurements were conducted in 0.1 mol L1, pH 8 phosphate buffer solution (PBS) including 0.1 mol L1 KCl, 0.5 mmol L1 of NAD+ (cofactor of the enzyme) and 1 mmol L1 of 1,2-napthoquinone-4-sulfonic acid sodium salt (NQS) as mediator with an applied potential of 0.23 V (vs. Ag/AgCl, 3 mol L1 NaCl). Analytical parameters of the biosensor were calculated and discussed. The biosensor was tested in rain water samples. RESULTS: Sensitivity was found to be 15 000 per mmol L1 (500 nA ppm1) in a linear range between 0.1 ppm and 3 ppm (3.3100 mu mol L1). A minimum detectable concentration of 4.5 ppb (0.15 mu mol L1) (S/N = 3) with a relative standard deviation (RSD) of 0.73% (n = 5) was obtained from the biosensor. Response time of the biosensor was very short, reaching 99% of its maximum response in about 4 s. The biosensor was also tested for formaldehyde measurements in rain water samples. Formaldehyde concentrations in samples were calculated using the proposed biosensor with recovery values ranged between 92.2 and 97.7% in comparison with the colorimetric Nash method. CONCLUSION: The poly(GMA-co-MTM)/FDH/PPy) electrode showed excellent measurement sensitivity in comparison with other formaldehyde biosensor studies. Strong chemical bonding between the enzyme and the copolymer was created via the epoxy groups of the composite film. The proposed biosensor could be used successfully in rain waters without a pretreatment step. (c) 2012 Society of Chemical Industry
BibTeX:
@article{Ozoner2013,
  author = {Ozoner, S. K. and Erhan, E. and Yilmaz, F. and Ergenekon, P. and Anil, I.},
  title = {Electrochemical biosensor for detection of formaldehyde in rain water},
  journal = {Journal of Chemical Technology and Biotechnology},
  year = {2013},
  volume = {88},
  number = {4},
  pages = {727--732},
  url = {://WOS:000316627600027},
  doi = {10.1002/jctb.3896}
}
Ozturk T, Veli S and Dimoglo A (2013), "The Effect of Seawater Conductivity on the Treatment of Leachate by Electrocoagulation", Chemical and Biochemical Engineering Quarterly. Vol. 27(3), pp. 347-354.
Abstract: The effect of seawater (SW) conductivity on the treatment of domestic solid waste leachates (DSWL) and hazardous solid waste leachates (HSWL) by means of EC was investigated. Seawater, which is a strong electrolyte with a rich content of ions, has been fed together with the leachates to the reactors with Fe and Al electrodes. In the experiments, the treatment was performed by mixing leachate (DSWL and HSWL) with seawater in the proportions of 1:1 and 1:3. The efficiency of the process was determined by observing such parameters of suspended solids as phosphate, sulphate, color and turbidity. It was determined that the removal efficiencies related to the amount of seawater added, increase for all parameters except sulphate ions removal. Obtained data showed the best removal efficiency for Fe and Al electrodes ranging from 67 % to 100 % in the phosphate content, color and turbidity. For suspended solids and sulfate ions, the removal efficiencies vary in the range of 50-70 %. The results show that seawater added to the process accelerates the EC process due to increasing conductivity and the presence of other ions in its composition.
BibTeX:
@article{Ozturk2013,
  author = {Ozturk, T. and Veli, S. and Dimoglo, A.},
  title = {The Effect of Seawater Conductivity on the Treatment of Leachate by Electrocoagulation},
  journal = {Chemical and Biochemical Engineering Quarterly},
  year = {2013},
  volume = {27},
  number = {3},
  pages = {347--354},
  url = {://WOS:000326058300012}
}
Sen N, Bektas N, Tekbas M and Yatmaz HC (2013), "Investigation of Total Organic Carbon (TOC) Removal in Domestic Wastewater by Photo-Fenton Process", Ekoloji. Vol. 22(88), pp. 58-64.
Abstract: Water consumption is increasing due to industrialization and population growth causing increased amounts of wastewater for discharge with the application of various treatment methods to treat wastewater. Advanced oxidation processes (AOPs) are also emerging as a promising technology both as an alternative treatment to conventional wastewater treatment methods and enhancement of current biological treatment methods, for especially highly toxic and non-biodegradable wastes. In this study, the applicability of Photo-Fenton oxidation method was investigated for the removal of total organic carbon (TOO) content in domestic wastewaters. The effects of various process variables on removal performance of the process were evaluated by examining Fe+2 and H2O2 dosages, temperature, pH, the types of reactors and UV lamps. Optimal experimental conditions for the wastewater treatment were found as 200 mg/L Fe+2, 15 mM H2O2 and 35 degrees C. Ultraviolet A (UVA) light type of lamp was used as a light source in order to use solar energy TOC removal efficiencies of 70-90% were obtained under various experimental conditions. As a result of this study, it can be concluded that Fe+2-H2O2/UV process can be safely used for the treatment of domestic wastewaters.
BibTeX:
@article{Sen2013,
  author = {Sen, N. and Bektas, N. and Tekbas, M. and Yatmaz, H. C.},
  title = {Investigation of Total Organic Carbon (TOC) Removal in Domestic Wastewater by Photo-Fenton Process},
  journal = {Ekoloji},
  year = {2013},
  volume = {22},
  number = {88},
  pages = {58--64},
  url = {://WOS:000326416700008},
  doi = {10.5053/ekoloji.2013.888}
}
Senturk E, Ynce M and Onkal Engin G (2013), "Assesment of Kinetic Parameters for Thermophilic Anaerobic Contact Reactor Treating Food-Processing Wastewater", International Journal of Environmental Research. Vol. 7(2), pp. 293-302.
Abstract: A thermophilic anaerobic contact reactor for the treatment of potato-processing wastewaters was designed as a continuous-flow, completely-mixed homogeneous system. The reactor was operated at ten different organic loading rates ranging from 0.84 g COD/L.d to 7.00 g COD/L.d for a duration of approximately 250 days. The fundamental way to maintain optimum operating conditions of anaerobic digestion systems is to have a well acquaintance with the dynamic behaviours of the process. For this purpose, different types of kinetic models were used in this study, namely the substrate balance, the maximum / specific substrate utilization rate and the methane production rate models. The experimental data obtained indicated that the models used were all applicable for the description of bio-kinetic behaviour of the thermophilic anaerobic contact reactor.
BibTeX:
@article{Senturk2013,
  author = {Senturk, E. and Ynce, M. and Onkal Engin, G.},
  title = {Assesment of Kinetic Parameters for Thermophilic Anaerobic Contact Reactor Treating Food-Processing Wastewater},
  journal = {International Journal of Environmental Research},
  year = {2013},
  volume = {7},
  number = {2},
  pages = {293--302},
  url = {://WOS:000315975900003}
}
Senturk E, Ince M and Engin GO (2013), "The effect of transient loading on the performance of a mesophilic anaerobic contact reactor at constant feed strength", Journal of Biotechnology. Vol. 164(2), pp. 232-237.
Abstract: Anaerobic contact reactor is a high rate anaerobic process consisting of an agitated reactor and a solids settling tank for recycling. It was proved earlier that this type of reactor design offers highly efficient performance in the conversion of organic matter to biogas. In this study, the effect of transient loading on reactor performance in terms of a number of key intermediates and parameters such as, COD removal, pH and alkalinity change, VFAs, effluent MLSS concentration and biogas efficiency over time was examined. For this purpose, a step increase of organic loading rate from 335 kg COD/m(3) day to 15.61 kg COD/m(3) day was employed. The hydraulic retention time decreased to a value of 8.42 h by an increase in the influent flow-rate during the transient loading. It was observed that the mesophilic anaerobic contact reactor (MACR) was quite resistant to large transient shocks. The reactor recovered back to its baseline performance only in 15 h after the shock loading was stopped. Hence, it can be concluded that this type of reactor design has a high potential in treating food processing wastewaters with varying flow characteristics. (C) 2012 Elsevier B.V. All rights reserved.
BibTeX:
@article{Senturk2013a,
  author = {Senturk, E. and Ince, M. and Engin, G. O.},
  title = {The effect of transient loading on the performance of a mesophilic anaerobic contact reactor at constant feed strength},
  journal = {Journal of Biotechnology},
  year = {2013},
  volume = {164},
  number = {2},
  pages = {232--237},
  url = {://WOS:000317995800008},
  doi = {10.1016/j.jbiotec.2012.08.016}
}
Senturk E (2013), "The treatment of zinc-cyanide electroplating rinse water using an electrocoagulation process", Water Science and Technology. Vol. 68(10), pp. 2220-2227.
Abstract: This paper investigates the treatment of zinc-cyanide electroplating rinse water using an electrocoagulation process (ECP). The effects of operating parameters such as electrode material, current density (2.5-40 A/m(2)), operating time (0-60 min), initial pH (5-12) and electrode connection mode (monopolar parallel (MP-P), monopolar series and bipolar series) on the ECP were evaluated to find the optimum operating conditions. At 20 A/m(2), 60 min, the highest removal efficiencies were obtained with 85 and 99% for Fe and 64 and 33% for Al electrodes, for cyanide and zinc, respectively. The optimum operating conditions were found to be 30 A/m(2) and 40 min, for the Fe electrode at the original pH (9.5) of the rinse water. Considering efficiency and economy, the MP-P connection mode was determined as the optimum connection mode.
BibTeX:
@article{Senturk2013b,
  author = {Senturk, E.},
  title = {The treatment of zinc-cyanide electroplating rinse water using an electrocoagulation process},
  journal = {Water Science and Technology},
  year = {2013},
  volume = {68},
  number = {10},
  pages = {2220--2227},
  url = {://WOS:000330122400016},
  doi = {10.2166/wst.2013.481}
}
Yuksel E, Eyvaz M and Gurbulak E (2013), "Electrochemical treatment of colour index reactive orange 84 and textile wastewater by using stainless steel and iron electrodes", Environmental Progress & Sustainable Energy. Vol. 32(1), pp. 60-68.
Abstract: In this study, two case studies were carried out: Electrocoagulation (EC) of a reactive textile dye solution and a textile wastewater. Stainless steel (SS) and iron (Fe) electrodes were used as sacrificial electrodes in parallel connection modes. Effects of pH, current density, and operating time on performance of EC were investigated. Optimum parameters obtained from dye experiments were applied to treatment of the textile wastewater. According to the experimental results, SS electrodes were found to be superior compared with Fe electrodes for treatment of both the dye and the textile wastewater. By using SS electrodes, the textile wastewater was electrocoagulated successfully with 89.7% of COD, 91.2% of TOC, 90.3% of turbidity, and 94.1% of TSS removal efficiencies as well as 2.43 kWh/m3 of energy and 0.05 kg/m3 of electrode consumptions, 1.061 kg/m3 of sludge production, and 0.62 $/m3 of total operating cost. (c) 2011 American Institute of Chemical Engineers Environ Prog, 32: 6068, 2013.
BibTeX:
@article{Yuksel2013,
  author = {Yuksel, E. and Eyvaz, M. and Gurbulak, E.},
  title = {Electrochemical treatment of colour index reactive orange 84 and textile wastewater by using stainless steel and iron electrodes},
  journal = {Environmental Progress & Sustainable Energy},
  year = {2013},
  volume = {32},
  number = {1},
  pages = {60--68},
  url = {://WOS:000313778300006},
  doi = {10.1002/ep.10601}
}
Akyol A (2012), "Treatment of paint manufacturing wastewater by electrocoagulation", Desalination. Vol. 285, pp. 91-99.
Abstract: Treatability of paint manufacturing wastewater (PMW) by electrocoagulation (EC) process was investigated. Effects of operating parameters for the EC process such as electrode type (Al or Fe), initial pH (2-10), current density (5-80 A/m(2)) and operating time (0-50 min) were evaluated for optimum operating conditions. The highest removal efficiencies for COD and TOC in PMW were obtained with 93% and 88% for Fe and 94% and 89% for Al electrodes at the optimum conditions (35 A/m(2), 15 min and pH 6.95). Operating costs for removal of PMW at the optimum conditions were calculated for Fe and Al electrodes as 0.187 (sic)/m(3) and 0.129 9sic)/m(3). Toxicity test was carried out to obtain information about toxic effect of the raw and treated wastewaters at optimum operating conditions. The samples measured by respirometric method contained hardly toxicities. Performance of Al electrode was better than that of Fe electrode in terms of removal efficiency and operating cost. (C) 2011 Elsevier B.V. All rights reserved.
BibTeX:
@article{Akyol2012,
  author = {Akyol, A.},
  title = {Treatment of paint manufacturing wastewater by electrocoagulation},
  journal = {Desalination},
  year = {2012},
  volume = {285},
  pages = {91--99},
  url = {://WOS:000300478100012},
  doi = {10.1016/j.desal.2011.09.039}
}
Anil I, Ozturk N, Alagha O and Ergenekon P (2012), "Optimization of solid-phase microextraction using Taguchi design to quantify trace level polycyclic aromatic hydrocarbons in water", Journal of Separation Science. Vol. 35(24), pp. 3561-3568.
Abstract: This article introduces a simple, rapid, and reliable solid-phase microextraction (SPME) method coupled with GC-MS for the quantitative determination of 16 polycyclic aromatic hydrocarbons in water. In this study, the Taguchi experimental design was used to optimize extraction conditions of polycyclic aromatic hydrocarbons using SPME method to obtain highly enriched analytes. Consequently, quantitative determination of polycyclic aromatic hydrocarbons in water was achieved by GC-MS technique. The selected parameters affecting enrichment of polycyclic aromatic hydrocarbons were sample extraction time, stirring speed, temperature, ionic strength, and pH. The study revealed that optimal operating conditions were found to be 90-min extraction time, 1400 rpm stirring speed, and 60 degrees C sample temperature. The effect of ionic strength and pH were shown to be insignificant. Optimized conditions were also reevaluated by placing the 16 polycyclic aromatic hydrocarbons into several subgroups based on their molecular weight. The extraction efficiency of polycyclic aromatic hydrocarbons with low molecular weight was shown to be a function of only the extracting temperature. Satisfactory results were obtained for linearity (0.9830.999), detection limits (2.6718.02 ng/L), accuracy (71.299.3%), and precision (4.313.5%). The optimum conditions reported by other design approaches were evaluated and generalized optimum conditions were suggested.
BibTeX:
@article{Anil2012,
  author = {Anil, I. and Ozturk, N. and Alagha, O. and Ergenekon, P.},
  title = {Optimization of solid-phase microextraction using Taguchi design to quantify trace level polycyclic aromatic hydrocarbons in water},
  journal = {Journal of Separation Science},
  year = {2012},
  volume = {35},
  number = {24},
  pages = {3561--3568},
  url = {://WOS:000312445900019},
  doi = {10.1002/jssc.201200550}
}
Bayer S, Arslan H and Karagunduz A (2012), "Influence of electrical field and electrocoagulation on the performance of submerged membrane bioreactors", In Euromembrane Conference 2012. Vol. 44, pp. 882-883.
BibTeX:
@incollection{Bayer2012,
  author = {Bayer, S. and Arslan, H. and Karagunduz, A.},
  editor = {Marsh, N.},
  title = {Influence of electrical field and electrocoagulation on the performance of submerged membrane bioreactors},
  booktitle = {Euromembrane Conference 2012},
  year = {2012},
  volume = {44},
  pages = {882--883},
  url = {://WOS:000378594000243},
  doi = {10.1016/j.proeng.2012.08.609}
}
Can F, Ozoner SK, Ergenekon P and Erhan E (2012), "Amperometric nitrate biosensor based on Carbon nanotube/Polypyrrole/Nitrate reductase biofilm electrode", Materials Science & Engineering C-Materials for Biological Applications. Vol. 32(1), pp. 18-23.
Abstract: This study describes the construction and characterization of an amperometric nitrate biosensor based on the Polypyrrole (PPy)/Carbon nanotubes (CNTs) film. Nitrate reductase (NR) was both entrapped into the growing PPy film and chemically immobilized via the carboxyl groups of CNTs to the CNT/PPy film electrode. The optimum amperometric response for nitrate was obtained in 0.1 M phosphate buffer solution (PBS), pH 7.5 including 0.1 M lithium chloride and 7 mM potassium ferricyanide with an applied potential of 0.13 V (vs. Ag/AgCl, 3 M NaCl). Sensitivity was found to be 300 nA/mM in a linear range of 0.44-1.45 mM with a regression coefficient of 0.97. The biosensor response showed a higher linear range in comparison to standard nitrate analysis methods which were tested in this study and NADH based nitrate biosensors. A minimum detectable concentration of 0.17 mM (S/N = 3) with a relative standard deviation (RSD) of 5.4% (n = 7) was obtained for the biosensor. Phenol and glucose inhibit the electrochemical reaction strictly at a concentration of 1 mu g/L and 20 mg/L, respectively. The biosensor response retained 70% of its initial response over 10 day usage period when used everyday. (C) 2011 Elsevier B.V. All rights reserved.
BibTeX:
@article{Can2012,
  author = {Can, F. and Ozoner, S. K. and Ergenekon, P. and Erhan, E.},
  title = {Amperometric nitrate biosensor based on Carbon nanotube/Polypyrrole/Nitrate reductase biofilm electrode},
  journal = {Materials Science & Engineering C-Materials for Biological Applications},
  year = {2012},
  volume = {32},
  number = {1},
  pages = {18--23},
  url = {://WOS:000298463800003},
  doi = {10.1016/j.msec.2011.09.004}
}
Dursun F, Ozoner SK, Demirci A, Gorur M, Yilmaz F and Erhan E (2012), "Vinylferrocene copolymers based biosensors for phenol derivatives", Journal of Chemical Technology and Biotechnology. Vol. 87(1), pp. 95-104.
Abstract: BACKGROUND: Newly synthesized composite films of P(glycidyl methacrylate85-co-vinylferrocene15)/Poly(glutaraldehyde)/ Polypyrrole [P(GMA85-co-VFc15)/PGA/PPy] and Poly(3-methylthienyl methacrylate85-co-vinylferrocene15)/Polypyrrole [P (MTM85-co-VFc15)/PPy] were used as matrices for tyrosinase based working electrodes. Direct covalent attachment of enzyme was carried out via the pendant epoxy groups of P(GMA85-co-VFc15) film, and the entrapment of enzyme was achieved for electrode containing P(MTM85-co-VFc15) film via electropolymerization of pyrrole in the presence of enzyme. The aim of the study is amperometric determination of various phenolics and investigation of the effect of interfacial interactions between enzyme and matrices on biosensor response. RESULTS: The lowest detection limit and the highest sensitivity for a P(GMA(85)-co-VFc(15)) based working electrode was found to be 0.113 mu mol L(-1) for 4-methoxyphenol, 40 nA (mu mol L(-1))-1 for pyrocatechol, respectively. Results showed that sensitivities were at least 8500-55000 times higher than the results in previous P(GMA-co-VFc) related studies. CONCLUSION: Facilitated electron transfer was achieved by means of mediator incorporated in conductive composites of VFc based redox copolymers. The effect was greater when enzyme was covalently bonded via epoxy groups due to the proximity of enzyme, mediator and electrode surface. Results showed that a multifunctional surface was provided on electrodes since the suggested copolymers could mediate an electrochemical reaction, and the multifunctional surface was capable of coating with conductive PPy. (C) 2011 Society of Chemical Industry
BibTeX:
@article{Dursun2012,
  author = {Dursun, F. and Ozoner, S. K. and Demirci, A. and Gorur, M. and Yilmaz, F. and Erhan, E.},
  title = {Vinylferrocene copolymers based biosensors for phenol derivatives},
  journal = {Journal of Chemical Technology and Biotechnology},
  year = {2012},
  volume = {87},
  number = {1},
  pages = {95--104},
  url = {://WOS:000298013400013},
  doi = {10.1002/jctb.2688}
}
Engin GO, Muftuoglu B and Senturk E (2012), "Dynamic biosorption characteristics and mechanisms of dried activated sludge and Spirulina platensis for the removal of Cu2+ ions from aqueous solutions", Desalination and Water Treatment. Vol. 47(1-3), pp. 310-321.
Abstract: During biosorption, removal is ensured by several mechanisms that occurred between living or nonliving microorganisms and transporting metal ions. In this study, the kinetics, equilibrium, and thermodynamics of the biosorption of Cu2+ onto dried activated sludge and Spirulina platensis from aqueous solution were investigated at different experimental conditions. The biosorption characteristics were investigated with respect to some of the significant parameters including the effect of pH, biosorbent dosage, and temperature. The Langmuir, Freundlich, and Temkin equilibrium adsorption models were studied. Results showed that Langmuir isotherm model fitted well the experimental data followed by the other isotherm models used. In order to determine the mechanism of the biosorption, kinetic models were applied. The results of the kinetic studies indicated that the biosorption processes fitted the pseudo-second-order model. The thermodynamic parameters were also calculated, and the values indicated that the biosorption process was spontaneous, exothermic, and more ordered in nature.
BibTeX:
@article{Engin2012,
  author = {Engin, G. O. and Muftuoglu, B. and Senturk, E.},
  title = {Dynamic biosorption characteristics and mechanisms of dried activated sludge and Spirulina platensis for the removal of Cu2+ ions from aqueous solutions},
  journal = {Desalination and Water Treatment},
  year = {2012},
  volume = {47},
  number = {1-3},
  pages = {310--321},
  url = {://WOS:000308996900037},
  doi = {10.1080/19443994.2012.696425}
}
Gengec E, Kobya M, Demirbas E, Akyol A and Oktor K (2012), "Optimization of baker's yeast wastewater using response surface methodology by electrocoagulation", Desalination. Vol. 286, pp. 200-209.
Abstract: In the present paper, electrocoagulation (EC) was employed for removals of color, chemical oxygen demand (COD) and total organic carbon (TOC) from baker' s yeast effluents (BYEs) in a batch EC reactor using aluminium electrodes. Optimizations of anaerobic (AE) and anaerobic-aerobic effluents (AAE) were carried out by response surface methodology to describe interactive effects of the three main process independent parameters (initial pH(i), current density and operating time) on removal efficiencies of color. COD and TOC. The responses were related to maximize color, COD and TOC removal efficiencies and to minimize operating cost in the EC process. The quadratic model fitted very well with the experimental data. R-2 correlation coefficients (>95%) for the removal efficiencies showed a high significance of the model. The maximum color, COD and TOC were 88%, 48% and 49% at 80 A/m(2), pH(i) 4 and 30 min for AE and 86%, 49% and 43% at 12.5 A/m(2), pH(i) 5 and 30 min for ME, respectively. The operating costs for AE and AAE at the optimized conditions were 0.418 (sic)/m(3) and 0.076 (sic)/m(3). (C) 2011 Elsevier B.V. All rights reserved.
BibTeX:
@article{Gengec2012,
  author = {Gengec, E. and Kobya, M. and Demirbas, E. and Akyol, A. and Oktor, K.},
  title = {Optimization of baker's yeast wastewater using response surface methodology by electrocoagulation},
  journal = {Desalination},
  year = {2012},
  volume = {286},
  pages = {200--209},
  url = {://WOS:000300648100026},
  doi = {10.1016/j.desal.2011.11.023}
}
Gengec E, Kobya M, Demirbas E, Akyol A and Oktor K (2012), "Electrochemical treatment of Baker's yeast wastewater containing melanoidin: optimization through response surface methodology", Water Science and Technology. Vol. 65(12), pp. 2183-2190.
Abstract: Effluents from Baker's yeast production plant contain a high percentage of color and a large amount of organic load. In the present study, Baker's yeast wastewater (BYW) is treated with the electrocoagulation (EC) process using Al electrodes. Operating parameters (pH, current density, color intensity and operating time) are optimized by response surface methodology (RSM). Quadratic models are developed for the responses which are removal efficiencies of color, chemical oxygen demand (COD) and total organic carbon (TOC) and operating cost (OC). Optimum operating parameters and responses are determined as initial pH 5.2, current density of 61.3 A/m(2) and operation time of 33 min, and 71% of color, 24% of COD, 24% of TOC removal efficiencies and OC of 0.869 (Sic)m(3), respectively. The quadratic model fits for all responses very well with R-2 (>0.95). This paper clearly shows that RSM is able to optimize the operating parameters to maximize the color, COD and TOC removal efficiencies and minimize the OC.
BibTeX:
@article{Gengec2012a,
  author = {Gengec, E. and Kobya, M. and Demirbas, E. and Akyol, A. and Oktor, K.},
  title = {Electrochemical treatment of Baker's yeast wastewater containing melanoidin: optimization through response surface methodology},
  journal = {Water Science and Technology},
  year = {2012},
  volume = {65},
  number = {12},
  pages = {2183--2190},
  url = {://WOS:000305718600014},
  doi = {10.2166/wst.2012.130}
}
Karagoz P, Rocha IV, Ozkan M and Angelidaki I (2012), "Alkaline peroxide pretreatment of rapeseed straw for enhancing bioethanol production by Same Vessel Saccharification and Co-Fermentation", Bioresource Technology. Vol. 104, pp. 349-357.
Abstract: Alkaline peroxide pretreatment of rapeseed straw was evaluated for conversion of cellulose and hemicellulose to fermentable sugars. After pretreatment, a liquid phase called pretreatment liquid and a solid phase were separated by filtration. The neutralized pretreatment liquids were used in a co-fermentation process, with Saccharomyces cerevisiae and Pichia stipitis. The solid fraction was used for simultaneous saccharification and co-fermentation process in the same vessel. The effects of various operating variables were investigated. Pretreatment with 5% (v/v) H2O2 at 50 degrees C for 1 h was found to be the optimal pretreatment combination with respect to overall ethanol production. At this condition, 5.73 g ethanol was obtained from pretreatment liquid and 14.07 g ethanol was produced by co-fermentation of solid fraction with P. stipitis. Optimum delignification was observed when 0.5 M MgSO4 was included in the pretreatment mixture, and it resulted in 0.92% increase in ethanol production efficiency. (C) 2011 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Karagoz2012,
  author = {Karagoz, P. and Rocha, I. V. and Ozkan, M. and Angelidaki, I.},
  title = {Alkaline peroxide pretreatment of rapeseed straw for enhancing bioethanol production by Same Vessel Saccharification and Co-Fermentation},
  journal = {Bioresource Technology},
  year = {2012},
  volume = {104},
  pages = {349--357},
  url = {://WOS:000301155800047},
  doi = {10.1016/j.biortech.2011.10.075}
}
Kobya M and Gengec E (2012), "Decolourization of melanoidins by a electrocoagulation process using aluminium electrodes", Environmental Technology. Vol. 33(21), pp. 2429-2438.
Abstract: The decolourization of melanoidins was studied with a batch electrocoagulation (EC) process using aluminium electrodes. The effects of conductivity (kappa = 500-3000 mu S/cm), initial pH(i) (4.2-8.2), current density (j = 2.5-7.5A/m(2)), initial melanoidin concentration (C-0 = 100-800 mg/L) and operating time (t(EC) = 0-60 min) were investigated on the decolourization efficiency. The results obtained from the EC process were extremely efficient and able to achieve a decolourization efficiency of >98% at pH(i) = 4.2, j = 5A/m(2), kappa = 2500 mu S/cm, C-0 = 100 mg/L and t(EC) = 10 min. The decolourization performance was dependent on pH(i) value since the lower pH values led to faster reactions and higher decolourization efficiency. Melanoidins in the EC process were removed by precipitation and charge neutralization at pH <6.5, and both adsorption and sweep coagulation by amorphous Al(OH)(3(s)) occurred at pH > 6.5. The operating cost was calculated as 0.0096 (sic)/m(3).
BibTeX:
@article{Kobya2012,
  author = {Kobya, M. and Gengec, E.},
  title = {Decolourization of melanoidins by a electrocoagulation process using aluminium electrodes},
  journal = {Environmental Technology},
  year = {2012},
  volume = {33},
  number = {21},
  pages = {2429--2438},
  url = {://WOS:000311120000008},
  doi = {10.1080/09593330.2012.671371}
}
Kobya M, Demirbas E and Sahin O (2012), "Effect of operational parameters on the removal of phenol from aqueous solutions by electrocoagulation using Fe and Al electrodes", Desalination and Water Treatment. Vol. 46(1-3), pp. 366-374.
Abstract: The removal of phenol from aqueous solutions in a batch electrocoagulation (EC) process using Fe and Al electrodes was investigated. Experiments were carried out to remove phenol by the EC covering a wide range of operating conditions such as initial pH (4-9), current density (20-80 A/m(2)), initial phenol concentration (20-80 mg/L), conductivity (500-1,500 mu S/cm), and operating time (0-100 min). The optimum operating conditions were determined as initial pH 7.0, initial concentration of 50 mg/L, current density of 40 A/m(2), operating time of 100 min, and conductivity of 1,200 mu S/cm for both electrodes, respectively. The removal efficiencies of phenol at the optimum operating conditions were 98.6% for Fe electrode and 99.2% for Al electrode. The operating cost and consumptions of electrode and energy in the EC process were calculated as 7.4 (sic)/m(3), 3.85 kg/m(3), and 43.27 kWh/m(3) for Fe electrode and 6.1 (sic)/m(3), 1.28 kg/m(3), and 42.18 kWh/m(3) for Al electrode, respectively. The EC process with Al electrode was found to be more efficient than the EC process with Fe electrode in terms of the removal efficiency and operating cost.
BibTeX:
@article{Kobya2012a,
  author = {Kobya, M. and Demirbas, E. and Sahin, O.},
  title = {Effect of operational parameters on the removal of phenol from aqueous solutions by electrocoagulation using Fe and Al electrodes},
  journal = {Desalination and Water Treatment},
  year = {2012},
  volume = {46},
  number = {1-3},
  pages = {366--374},
  url = {://WOS:000304590700040},
  doi = {10.1080/19443994.2012.677565}
}
Konyar M, Yatmaz HC and Ozturk K (2012), "Sintering temperature effect on photocatalytic efficiencies of ZnO/TiO2 composite plates", Applied Surface Science. Vol. 258(19), pp. 7440-7447.
Abstract: Self-supporting ZnO/TiO2 composite plates were fabricated at a molar ratio of ZnO (wurtzite):TiO2 (anatase) = 1:1 by tape casting and lamination process. The laminated green plates were sintered in air at relatively low temperatures, ranging from 600 to 700 degrees C and finally characterized by TGA, BET, XRD and SEM-EDX analysis. Photocatalytic efficiencies of the plates were evaluated using a model aqueous dye solution (50 mg/L RR180). Decolorization effect of the photocatalyst plates was carried out in a laboratory scale quartz photo-reactor under UVA light irradiation. It was found that increasing sintering temperatures reduced the efficiencies of the plates. This is due not only to decrease in the surface area of the plates because of coarsening, but also to reactions between phase-pure ZnO and TiO2 leading to the formation of unwanted binary Zn2Ti3O8 and Zn2TiO4 compounds. Up to 76% color removal was successfully achieved for the plates sintered at 600 degrees C at the end of 90 min oxidation process. (C) 2012 Elsevier B.V. All rights reserved.
BibTeX:
@article{Konyar2012,
  author = {Konyar, M. and Yatmaz, H. C. and Ozturk, K.},
  title = {Sintering temperature effect on photocatalytic efficiencies of ZnO/TiO2 composite plates},
  journal = {Applied Surface Science},
  year = {2012},
  volume = {258},
  number = {19},
  pages = {7440--7447},
  url = {://WOS:000304254000034},
  doi = {10.1016/j.apsusc.2012.04.058}
}
Kose B, Ozgun H, Ersahin ME, Dizge N, Koseoglu-Imer DY, Atay B, Kaya R, Altinbas M, Sayili S, Hoshan P, Atay D, Eren E, Kinaci C and Koyuncu I (2012), "Performance evaluation of a submerged membrane bioreactor for the treatment of brackish oil and natural gas field produced water", Desalination. Vol. 285, pp. 295-300.
Abstract: Produced water, which is co-produced during oil and gas manufacturing, represents one of the largest sources of oily wastewaters. Therefore, treatment of this produced water may improve the economic viability and lead to a new source of water for beneficial use. In this study a submerged hollow fiber membrane bioreactor (MBR) has been studied experimentally for the treatment of brackish oil and natural gas field produced water. This type of wastewater is also characterized with relatively moderate to high amount of salt, oil and total petroleum hydrocarbons (TPH). However, the bacteria which are growing in conventional activated sludge and MBR cannot survive at these strict conditions, therefore acclimation of the bacteria is of vital importance. The performance of the biological system, membrane permeability, the rate and extent of TPH biodegradability have been investigated under different sludge age and F/M ratios. The results obtained by gas chromatography analyses showed that the MBR system could be very effective in the removal of TPH from produced water and a significant improvement in the effluent quality was achieved. (C) 2011 Elsevier By. All rights reserved.
BibTeX:
@article{Kose2012,
  author = {Kose, B. and Ozgun, H. and Ersahin, M. E. and Dizge, N. and Koseoglu-Imer, D. Y. and Atay, B. and Kaya, R. and Altinbas, M. and Sayili, S. and Hoshan, P. and Atay, D. and Eren, E. and Kinaci, C. and Koyuncu, I.},
  title = {Performance evaluation of a submerged membrane bioreactor for the treatment of brackish oil and natural gas field produced water},
  journal = {Desalination},
  year = {2012},
  volume = {285},
  pages = {295--300},
  url = {://WOS:000300478100039},
  doi = {10.1016/j.desal.2011.10.016}
}
Koseoglu-Imer DY, Dizge N and Koyuncu I (2012), "Enzymatic activation of cellulose acetate membrane for reducing of protein fouling", Colloids and Surfaces B-Biointerfaces. Vol. 92, pp. 334-339.
Abstract: In this study, the surface of cellulose acetate (CA) ultrafiltration membrane was activated with serine protease (Savinase) enzyme to reduce protein fouling. Enzyme molecules were covalently immobilized with glutaraldehyde (cross-linking agent) onto the surface of CA membranes. The membrane activation was verified using filtration experiments and morphological analysis. Scanning electron microscopy (SEM) images and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy of the activated membrane when compared with raw membrane were confirmed that the enzyme was immobilized onto the membrane surface. The immobilization efficiencies changed from 13.2 to 41.2% according to the enzyme ratios from 2.5 to 10.0 mg/mL. However, the permeability values decreased from 232 +/- 6 to 121 +/- 4 L/m(2) h bar with increasing enzyme concentration from 2.5 to 10.0 mg/mL. In fouling experiments, bovine serum albumin (BSA) was used as the protein model solution and activated sludge was used as the model biological sludge. Enzyme-activated membranes exhibited good filtration performances and protein rejection efficiencies were compared with raw CA membrane. Also the relative flux reduction (RFR) ratios of membranes were calculated as 97% and 88% for raw CA and enzyme-activated membranes (5 mg/mL savinase), respectively. The membrane activated with Savinase enzyme could be proposed as a surface treatment method before filtration to mitigate protein fouling. (C) 2011 Elsevier By. All rights reserved.
BibTeX:
@article{Koseoglu-Imer2012,
  author = {Koseoglu-Imer, D. Y. and Dizge, N. and Koyuncu, I.},
  title = {Enzymatic activation of cellulose acetate membrane for reducing of protein fouling},
  journal = {Colloids and Surfaces B-Biointerfaces},
  year = {2012},
  volume = {92},
  pages = {334--339},
  url = {://WOS:000300859000047},
  doi = {10.1016/j.colsurfb.2011.12.013}
}
Kurt E, Koseoglu-Imer DY, Dizge N, Chellam S and Koyuncu I (2012), "Pilot-scale evaluation of nanofiltration and reverse osmosis for process reuse of segregated textile dyewash wastewater", Desalination. Vol. 302, pp. 24-32.
Abstract: Segregated wastewaters from dyewash processes in a weaving industry were treated for decolorization, as well as the removal of chemical oxygen demand and salts using a pilot-scale membrane system. Nanofiltration (NF-270) and reverse osmosis (RO-XLE) membranes were evaluated under different operating modes namely batch concentrate-recycle mode and continuous mode without concentrate recycle. Activation energies of pure water permeation across the RO-XLE and NF270 membranes were measured to be 6.51 +/- 0.53 kJ mol(-1) and 3.87 +/- 0.24 kJ mol(-1) respectively. The average flux values of NF-270 and RO-XLE membranes were 51.0 +/- 17.5 l m(-2) h(-1) and 27 +/- 6.5 l m(-2) h(-1) in batch mode, respectively. The average flux values of membranes at continuous mode were 42 +/- 6 l m(-2) h(-1) for NF-270 membrane and 26 +/- 3 l m(-2) h(-1) for RO-XLE membrane. An empirical equation correlating the instantaneous flux to inlet COD, conductivity and color values were obtained using Statsoft STATISTICA 8.0. High COD, conductivity and color removal efficiencies were achieved demonstrating the applicability of membrane treatment for textile industry wastewaters. Hence, the highly polluted dyewash wastewater could be effectively treated by membranes to produce water for process reuse in the dyewashing process. (c) 2012 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kurt2012,
  author = {Kurt, E. and Koseoglu-Imer, D. Y. and Dizge, N. and Chellam, S. and Koyuncu, I.},
  title = {Pilot-scale evaluation of nanofiltration and reverse osmosis for process reuse of segregated textile dyewash wastewater},
  journal = {Desalination},
  year = {2012},
  volume = {302},
  pages = {24--32},
  url = {://WOS:000308450300002},
  doi = {10.1016/j.desal.2012.05.019}
}
Odabasi M and Cetin B (2012), "Determination of octanol-air partition coefficients of organochlorine pesticides (OCPs) as a function of temperature: Application to air-soil exchange", Journal of Environmental Management. Vol. 113, pp. 432-439.
Abstract: Octanol-air partition coefficients (K-OA) for 7 organochlorine pesticides (OCPs) were determined as a function of temperature using the GC retention time method. Log K-OA values at 25 degrees C ranged over two orders of magnitude, between 8.32 (chlorpyrifos) and 10.48 (methoxychlor). The determined K-OA values were within a factor of 0.5 (endosulfan sulfate) to 7.9 (endrin aldehyde) for values calculated as the ratio of octanol-water partition coefficient to dimensionless Henry's law constant. The internal energies of phase transfer between octanol and air (Delta U-OA) ranged between 71.8 and 95.4 kJ mol(-1) and they were within the reported range for OCPs (55.8-105 kJ mol(-1)). Atmospheric and soil OCP concentrations were also measured in Izmir, Turkey, and data used to investigate the soil-air gas exchange. Net soil-air gas exchange fluxes of OCPs ranged from -0.01 (volatilization, cis-nonachlor) to 56.4 ng m(-2) day(-1) (deposition, chlorpyrifos) in winter, while in summer they ranged from -0.03 (trans-nonachlor) to 329 ng m(-2) day(-1) (endosulfan I). In both sampling periods, endosulfan I and II, trans-nonachlor, p,p'-DDD and p,p'-DDT were generally deposited to the soil while gamma-HCH and heptachlor epoxide mostly volatilized. Fluxes of other OCPs were variable (volatilization or absorption) due to their largely fluctuating ambient air concentrations. Calculated dry deposition and recently measured wet deposition fluxes were used to estimate the relative importance of different mechanisms (i.e., dry deposition, wet deposition, gas absorption, and volatilization) to the local soil pollutant inventory. Generally, all mechanisms contributed significantly to the soil OCP inventory. Volatilization fluxes were generally much lower than the sum of input fluxes (dry deposition, wet deposition and gas absorption) for most of the OCPs indicating a net deposition to the soil. (C) 2012 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Odabasi2012,
  author = {Odabasi, M. and Cetin, B.},
  title = {Determination of octanol-air partition coefficients of organochlorine pesticides (OCPs) as a function of temperature: Application to air-soil exchange},
  journal = {Journal of Environmental Management},
  year = {2012},
  volume = {113},
  pages = {432--439},
  url = {://WOS:000313153000048},
  doi = {10.1016/j.jenvman.2012.10.010}
}
Odabasi M, Bayram A, Elbir T, Dumanoglu Y, Kara M, Altiok H and Cetin B (2012), "Investigation of seasonal variations and sources of atmospheric polychlorinated naphthalenes (PCNs) in an urban area", Atmospheric Pollution Research. Vol. 3(4), pp. 477-484.
Abstract: Atmospheric concentrations of 32 polychlorinated naphthalene (PCN) congeners were determined at four sites (i.e., Suburban, Urban 1, Urban 2, and Industrial) in Izmir, Turkey and their possible sources were investigated. Total PCN (Sigma 32PCN) concentrations ranged between 5.2 (Suburban 1) to 162 pg m(-3) (Urban 1) in summer, while in winter, they ranged from 3.7 (Suburban) to 229 pg m-3 (Urban 1). PCN-24/14 was the dominant congener at all sites (contributing 12-27% to Sigma(32)PCNs), followed by PCN-33/34/37, PCN-28/43, PCN-17/25, PCN-23 and PCN-19. Investigation of possible sources indicated that the combustion processes also contribute substantially to atmospheric PCN concentrations in addition to emissions from sources related to historical use of technical mixtures. (C) Author(s) 2012. This work is distributed under the Creative Commons Attribution 3.0 License.
BibTeX:
@article{Odabasi2012a,
  author = {Odabasi, M. and Bayram, A. and Elbir, T. and Dumanoglu, Y. and Kara, M. and Altiok, H. and Cetin, B.},
  title = {Investigation of seasonal variations and sources of atmospheric polychlorinated naphthalenes (PCNs) in an urban area},
  journal = {Atmospheric Pollution Research},
  year = {2012},
  volume = {3},
  number = {4},
  pages = {477--484},
  url = {://WOS:000310516300017},
  doi = {10.5094/apr.2012.055}
}
Olmezoglu E, Herand BK, Oncel MS, Tunc K and Ozkan M (2012), "Copper bioremoval by novel bacterial isolates and their identification by 16S rRNA gene sequence analysis", Turkish Journal of Biology. Vol. 36(4), pp. 469-476.
Abstract: Copper-tolerant bacteria were isolated from soil samples taken from a region where metal industries are located. After selecting 2 isolates with relatively higher bioremoval efficiency, the effects of increasing copper concentration, pH, and temperature on the bioremoval efficiency of the growing isolates were determined. Strain N1c and strain N5a showed maximal bioremoval efficiency of 82% and 75%, respectively, in 20 mg/L copper-containing medium at pH 6.8 and 30 degrees C. Although the isolates did not grow well at pH 5, a low amount of copper was removed at pH 5. Slow growth of N5a at pH 5 allowed for 26% copper removal at hour 80 of incubation. Optimal copper bioremoval of the cells occurred at pH 6.8 and 30 degrees C. When grown at 37 degrees C under aerated conditions, N1c showed 31.7% bioremoval in the presence of 100 mg/L copper, and N5a was much more resistant to copper compared to NI c and E. coli. The isolates were identified by 16S rRNA gene sequence analysis. The 16S rRNA gene sequence of N5a showed 96%-97% similarity to Pseudomonas stutzeri and other Pseudomonas spp. The 16S rRNA gene sequence of N1c was 96% similar to Achromobacter sp., Alcaligenes sp., and a novel genus, Collimonas.
BibTeX:
@article{Olmezoglu2012,
  author = {Olmezoglu, E. and Herand, B. K. and Oncel, M. S. and Tunc, K. and Ozkan, M.},
  title = {Copper bioremoval by novel bacterial isolates and their identification by 16S rRNA gene sequence analysis},
  journal = {Turkish Journal of Biology},
  year = {2012},
  volume = {36},
  number = {4},
  pages = {469--476},
  url = {://WOS:000307042100012},
  doi = {10.3906/biy-1104-15}
}
Ondul E, Dizge N and Albayrak N (2012), "Immobilization of Candida antarctica A and Thermomyces lanuginosus lipases on cotton terry cloth fibrils using polyethyleneimine", Colloids and Surfaces B-Biointerfaces. Vol. 95, pp. 109-114.
Abstract: In this study, cotton terry cloth fibrils were coated with 0.2% polyethyleneimine (PEI). Lipases from Candida antarctica A (CALA) and Thermomyces lanuginosus (TL) were immobilized on this support through adsorption followed by cross-linking with 0.2% glutaraldehyde. PEI-enzyme aggregates formation and growth of aggregates on cotton cloth fibrils lead to multilayer immobilization of the lipases. PEI and lipase was mixed to form PEI-enzyme complex/aggregate. The highest amount of enzyme precipitate was obtained at the PEI to enzyme ratio of 1/20-1/40 for both lipases. The effect of pH was also investigated for aggregates formation. The results showed that when pH values were below 8, aggregation and precipitation were not occurred for C. antarctica A lipase. However, pH did not affect PEI-enzyme aggregate formation for T. lanuginosus lipase. Immobilized enzyme amount was approximately 180 mg/g support and 200 mg/g support for T. lanuginosus and C. antarctica A lipases, respectively. Effect of the reaction temperature on the relative activity of the free and immobilized lipases at various temperature (30-80 degrees C) was studied. It was found that immobilization had no effect on the optimum temperature and it was 60 degrees C for both free and immobilized enzymes. The effect of operational and storage stability on activity of free and immobilized lipases were also investigated. Immobilized lipases exhibited that they could be stored at room temperature with a little activity lost during 28 days. (C) 2012 Elsevier B.V. All rights reserved.
BibTeX:
@article{Ondul2012,
  author = {Ondul, E. and Dizge, N. and Albayrak, N.},
  title = {Immobilization of Candida antarctica A and Thermomyces lanuginosus lipases on cotton terry cloth fibrils using polyethyleneimine},
  journal = {Colloids and Surfaces B-Biointerfaces},
  year = {2012},
  volume = {95},
  pages = {109--114},
  url = {://WOS:000304686200015},
  doi = {10.1016/j.colsurfb.2012.02.020}
}
Ozkurt N and Karpuzcu M (2012), "INVESTIGATION OF SO2 RESULTS WITH PASSIVE DIFFUSIVE SAMPLERS AROUND 18 MART CAN THERMAL POWER PLANT IN CANAKKALE", Fresenius Environmental Bulletin. Vol. 21(1), pp. 3-10.
Abstract: In Turkey, one of the major air pollution sources is energy utilization due to the combustion of lignite. Increasing energy consumption and use of domestic lignite causes the unavoidable increase of SO2 pollution. Especially around large combustion plants (i.e. coal-fired thermal power plants), monitoring cost is critical for evaluation of environmental impacts, since their impact area is very large, depending on measurement techniques. Since passive diffusion samplers have the potential to provide a cheap and effective means of determining atmospheric trace gas concentrations, they were preferred for monitoring of SO2 concentrations in the impact area of Can Thermal Power Plant. For more accurate and continuous measurements of air pollutants, an automated continuous measurement analyzer using UV fluorescence was also used. The passive diffusion samplers were co-located with the available AQMS (Air Quality Monitoring Stations), and during the year 2006, the continuous analyzer was co-located with the AQMS in Bayramic County, near the Can Thermal Power Plant. The two different measurement techniques were used to monitor and compare monthly measurements using least-square regression. The temporal variations observed with the passive samplers and AQMS data for SO2 concentrations were similar. The 8-months comparison of 2006, between passive sampler technique and automated analyzer measurement suggests that, in most cases, SO2 results correlate fairly well.
BibTeX:
@article{Ozkurt2012,
  author = {Ozkurt, N. and Karpuzcu, M.},
  title = {INVESTIGATION OF SO2 RESULTS WITH PASSIVE DIFFUSIVE SAMPLERS AROUND 18 MART CAN THERMAL POWER PLANT IN CANAKKALE},
  journal = {Fresenius Environmental Bulletin},
  year = {2012},
  volume = {21},
  number = {1},
  pages = {3--10},
  url = {://WOS:000301816400001}
}
Ozman-Say AN and Balkis N (2012), "PHYTOPLANKTON ASSEMBLAGES IN THE COASTAL ZONE OF THE GULF OF ISKENDERUN - NORTH EASTERN MEDITERRANEAN", Pakistan Journal of Botany. Vol. 44(5), pp. 1785-1798.
Abstract: In order to determine the phytoplankton species in the Gulf of Iskenderun and the environmental factors that affect the distributions of the species, samples were collected horizontally with a plankton net at 9 stations in November 2005 and June 2006. As a result of the examination of the samples, 95 phytoplankton species belonging to 3 classes were identified. 12 species were new records for the Gulf of Iskenderun, one (Navicula transitans Cleve, 1883) of them was a new report for all the Turkish seas. Dinoflagellates were the majority group of the species composition (53.7%), followed by diatoms (45.3%). Most of the species identified in this study consist of phytoplanktonic algae reported in the Eastern Mediterranean earlier. These species were neritic, oceanic, temperate and subtropic. In this study, 18 species defined as potentially harmful algal species and three of them were also toxic. Primary hydrographic conditions, such as temperature (20.2-28.7 degrees C), salinity (31.0-39 ppt) and dissolved oxygen (7.21-8.60 mg l(-1)), were recorded on each sampling occasion. In addition, a check-list of the phytoplankton species recorded up to this date was given and totally 269 species were recorded from the Gulf of Iskenderun.
BibTeX:
@article{Ozman-Say2012,
  author = {Ozman-Say, A. N. and Balkis, N.},
  title = {PHYTOPLANKTON ASSEMBLAGES IN THE COASTAL ZONE OF THE GULF OF ISKENDERUN - NORTH EASTERN MEDITERRANEAN},
  journal = {Pakistan Journal of Botany},
  year = {2012},
  volume = {44},
  number = {5},
  pages = {1785--1798},
  url = {://WOS:000311185700046}
}
Ozoner SK (2012), "Poly(glycidyl methacrylate-co-3-thienyl-methylmethacrylate) based working electrodes for hydrogen peroxide biosensing", Journal of Chemical Technology and Biotechnology. Vol. 87(1), pp. 146-152.
Abstract: BACKGROUND: Hydrogen peroxide biosensors based on Poly(glycidyl methacrylate-co-3-thienylmethylmethacrylate)/ Polypyrrole [Poly(GMA-co-MTM)/PPy] composite film were reported. Poly(GMA-co-MTM) including various amounts of GMA and MTM monomers was synthesized via the radical polymerization. Enzyme horseradish peroxidase (HRP) was trapped in Poly(GMA-co-MTM)/PPy composites during the electropolymerization reaction between pyrrole and thiophene groups of MTM monomer, and chemically bonded via the epoxy groups of GMA. Analytical parameters of the fabricated electrodes were calculated and are discussed in terms of film electroactivity and mass transfer conditions of the composite films. RESULTS: The amount of electroactive HRP was found to be 1.25, 0.34 and 0.213 mu g for the working electrodes of Poly( GMA(30%)-co-MTM70%)/PPy/HRP, Poly( GMA(85%)-co-MTM15%)/PPy/HRP and Poly(GMA(90%)-co-MTM10%)/PPy/HRP, respectively. Optimal response of the fabricated electrodes was obtained at pH 7 and an operational potential of -0.35 V. It was observed that effective enzyme immobilization and electroactivity of the composite films could be changed by changing the ratios of GMA and MTM fractions of Poly( GMA-co-MTM) based working electrodes. CONCLUSION: The amount of electroactive enzyme increases with increasing MTM content of the final copolymer. High operational stabilities of the biosensors can be attributed to the strong covalent enzyme linkage via the epoxy groups of GMA due to preventing enzyme deterioration and loss. A more convenient microenvironment for mass transfer was provided for the electrodes by higher GMA ratios. It is observed that mass transfer is dominated by the mechanism of electron transfer to obtain effective sensitivity values. This work contributes to discussions clarifying the problems regarding the design parameters of biosensors. (C) 2011 Society of Chemical Industry
BibTeX:
@article{Ozoner2012,
  author = {Ozoner, S. K.},
  title = {Poly(glycidyl methacrylate-co-3-thienyl-methylmethacrylate) based working electrodes for hydrogen peroxide biosensing},
  journal = {Journal of Chemical Technology and Biotechnology},
  year = {2012},
  volume = {87},
  number = {1},
  pages = {146--152},
  url = {://WOS:000298013400019},
  doi = {10.1002/jctb.2695}
}
Samuk B, Kabdash I, Tunay O and Karpuzcu M (2012), "FLUORIDE ABATEMENT FROM ALUMINIUM SURFACE TREATMENT EFFLUENTS BY ELECTROCOAGULATION", Fresenius Environmental Bulletin. Vol. 21(10A), pp. 3114-3121.
Abstract: In the present study, the treatability of an aluminium surface treatment effluent bearing high amount of fluoride (3360-6440 mg/L) and aluminium (2695-4690 mg/L) together with organic matter (340-370 mg COD/L) by electrocoagulation using aluminium electrodes was studied. The effect of varying operating parameters such as the applied current density (3.7-29.8 mA/cm(2)), initial pH (2.55-3.86) and electrolyte (NaCl) concentration (500-3000 mg/L) on fluoride abatement as well as organic matter and aluminium removals was investigated. The results of the experimental study indicated that an increase in the applied current density significantly enhanced EC process performance whereas there was no significant effect of electrolyte (NaCl) concentration on pollutant removal efficiency. The electrocoagulation process proved to be effective and efficient for the treatment of aluminium surface treatment process effluents providing fluoride abatements up to 99% together with around 90% aluminium removals.
BibTeX:
@article{Samuk2012,
  author = {Samuk, B. and Kabdash, I. and Tunay, O. and Karpuzcu, M.},
  title = {FLUORIDE ABATEMENT FROM ALUMINIUM SURFACE TREATMENT EFFLUENTS BY ELECTROCOAGULATION},
  journal = {Fresenius Environmental Bulletin},
  year = {2012},
  volume = {21},
  number = {10A},
  pages = {3114--3121},
  url = {://WOS:000312412700016}
}
Sonmezay A, Salim Oncel M and Bektas N (2012), "Adsorption of lead and cadmium ions from aqueous solutions using manganoxide minerals", Transactions of Nonferrous Metals Society of China. Vol. 22(12), pp. 3131-3139.
Abstract: Removal of lead and cadmium ions from aqueous solutions by adsorption process was investigated. Low cost and locally available natural mineral of manganoxide mineral was used as an adsorbent. The kinetics of adsorption process data was examined using the pseudo-first-order, pseudo-second-order kinetics and the intra-particle diffusion models. The rate constants of adsorption for all these kinetics models were calculated and compared. The adsorption kinetics was best described by the pseudo second-order model. The Langmuir and Freundlich adsorption isotherm models were applied to the experimental equilibrium data at different temperatures. The experimental data well fitted to Langmuir isotherm model. The maximum adsorption capacities of manganoxide mineral for lead and cadmium ions were calculated from the Langmuir isotherm and were 98 and 6.8 mg/g, respectively. Thermodynamic parameters such as the change of Gibbs free energy, enthalpy and entropy of adsorption were also calculated and it was found that the lead and cadmium uptake reactions by manganoxide mineral were endothermic and spontaneous in nature. Therefore, manganoxide mineral can be used as adsorbents for lead and cadmium ions removal processes as an alternative natural mineral among the others.
BibTeX:
@article{Sonmezay2012,
  author = {Sonmezay, A. and Salim Oncel, M. and Bektas, N.},
  title = {Adsorption of lead and cadmium ions from aqueous solutions using manganoxide minerals},
  journal = {Transactions of Nonferrous Metals Society of China},
  year = {2012},
  volume = {22},
  number = {12},
  pages = {3131--3139},
  url = {://WOS:000317417800040},
  doi = {10.1016/s1003-6326(12)61765-8}
}
Sulak MT and Yatmaz HC (2012), "Removal of textile dyes from aqueous solutions with eco-friendly biosorbent", Desalination and Water Treatment. Vol. 37(1-3), pp. 169-177.
Abstract: Inexpensive and eco-friendly biosorbent wheat bran has been successfully utilized for the removal of textile dyes from aqueous solutions. Remazol Red F3B (Reactive red 180) was initially used as a model textile dye. The effects of contact time, pH, initial dye concentration, biosorbent dose and temperature were investigated. The optimum biosorption conditions were found as following: contact time 4 h, initial pH 2.0, initial dye concentration 200 mg/l, biosorbent dose 0.25 g and temperature 20 degrees C. The results indicate that acidic pH supported the biosorption of dyes on the wheat bran. The biosorption capacity was 39.42 mg/g for this dye. Using optimum biosorption conditions, five other dye types with reactive, direct and acidic structures were also investigated for biosorption capacity. The Langmuir and Freundlich models were evaluated using the experimental data and the experimental results showed that the Langmuir equation fit better than the Freundlich equation. Different thermodynamic parameters i.e., changes in standard free energy, enthalpy and entropy have also been evaluated and it has been found that the reaction was spontaneous and exothermic in nature. Finally, the effect of biosorbent surface was analyzed by scanning electron microscope (SEM). SEM images showed reasonable agreement with adsorption measurements.
BibTeX:
@article{Sulak2012,
  author = {Sulak, M. T. and Yatmaz, H. C.},
  title = {Removal of textile dyes from aqueous solutions with eco-friendly biosorbent},
  journal = {Desalination and Water Treatment},
  year = {2012},
  volume = {37},
  number = {1-3},
  pages = {169--177},
  url = {://WOS:000300362900021},
  doi = {10.5004/dwt.2012.2928}
}
Sulak MT, Erhan E and Keskinler B (2012), "Electrochemical Phenol Biosensor Configurations Based on Nanobiocomposites", Sensors and Materials. Vol. 24(3), pp. 141-152.
Abstract: Different biosensor configurations were constructed based on nanobiocomposites for the detection of phenol. The immobilization of laccase (TvLac) was achieved on a glassy carbon (GC) with polypyrrole (PPy), polypyrrole-multiwall carbon nanotube (PPy-MWCNT), and polypyrrole-multiwall carbon nanotube-Prussian blue (PPy-MWCNT-PB) composites via electrochemical polymerization. A comparative study was made of the analytical properties of the biosensors corresponding to the three configurations, namely, GC/PPy-TvLac, GC/PPy-TvLac-MWCNT, and GC/PPy-TvLac-MWCNT-PB. All the configurations indicated that the (TvLac-MWCNT-PB) nanobiocomposites were entrapped within the porous PPy film and resulted in a hybrid film that showed a high electrocatalytic ability toward the oxidation of phenol at a potential of -200 mV vs Ag/AgCl. The GC/PPy-TvLac-MWCNT-PB working electrode gave performance characteristics with high sensitivity (309.1 nA/mu M), low detection limit, and good stability. This electrode allowed the determination of phenol in the 0.2 -2.56 mu M concentration range. The sensitivities (S/N = 3) for phenol obtained from the different working electrodes were found to be 4.56, 91.03, and 309.1 mu M, respectively.
BibTeX:
@article{Sulak2012a,
  author = {Sulak, M. T. and Erhan, E. and Keskinler, B.},
  title = {Electrochemical Phenol Biosensor Configurations Based on Nanobiocomposites},
  journal = {Sensors and Materials},
  year = {2012},
  volume = {24},
  number = {3},
  pages = {141--152},
  url = {://WOS:000303619900003}
}
Vergili I, Kaya Y, Sen U, Gonder ZB and Aydiner C (2012), "Techno-economic analysis of textile dye bath wastewater treatment by integrated membrane processes under the zero liquid discharge approach", Resources Conservation and Recycling. Vol. 58, pp. 25-35.
Abstract: The present study was intended to determine the usefulness of the zero liquid discharge (ZLD) approach in treating textile dye bath wastewater via integrated membrane processes. These processes included various combinations of ultrafiltration (UF), loose nanofiltration (NF1), tight nanofiltration (NF2) and reverse osmosis (RO). The technological and economic performance of four scenarios (UF/NF2 (S (I)), NF1/NF2 (S (II)), NFI/RO (S (III)) and UF/NF2/RO (S (IV))), each followed by membrane distillation (MD), were comparatively analysed. The factors considered were capital and operating costs, revenues, benefit/cost (B/C) ratios and pay-back times. The last two scenarios, those including RO, provided the best effluent quality at the end of the pressure-driven membrane filtration process. However, these scenarios were not the most economical options because of the decreased benefits of recycling soda ash and NaCl obtained from the treated wastewater. The unit treatment costs of the scenarios were 1.37, 1.38, 2.16 and 2.01 $/m(3) of influent for S (I), 5(II), S (III) and S (IV), respectively, with return periods of 0.87, 0.91, 2.07 and 1.51 years. The best technological and economic performance was estimated for S (I) and S (II), as indicated by the B/C ratios 3.58 and 3.55, respectively. At the break-even point of 15 years, S (I) required an incineration cost of 77.5 $/m(3) of MD concentrate, whereas the corresponding costs associated with the other three scenarios were estimated to be 75.7, 43.0 and 35.5 $/m(3) of MD concentrate, respectively. It was finally concluded that the ZLD approach is most useful in processing textile dye bath waste and recycling treated wastewater. This process is both technically feasible and economically viable, as indicated by the high B/C ratio. However, the unit incineration cost associated with the concentrate would limit the return period of the investment, and the success of this method would also depend principally on the real volume of MD processed due to its large contribution (70-90%) to the B/C ratio. (C) 2011 Elsevier B.V. All rights reserved.
BibTeX:
@article{Vergili2012,
  author = {Vergili, I. and Kaya, Y. and Sen, U. and Gonder, Z. B. and Aydiner, C.},
  title = {Techno-economic analysis of textile dye bath wastewater treatment by integrated membrane processes under the zero liquid discharge approach},
  journal = {Resources Conservation and Recycling},
  year = {2012},
  volume = {58},
  pages = {25--35},
  url = {://WOS:000300127400004},
  doi = {10.1016/j.resconrec.2011.10.005}
}
Yuksel E, Gurbulak E and Eyvaz M (2012), "Decolorization of a reactive dye solution and treatment of a textile wastewater by electrocoagulation and chemical coagulation: Techno-economic comparison", Environmental Progress & Sustainable Energy. Vol. 31(4), pp. 524-535.
Abstract: In this study, the effects of operational parameters such as initial pH, current density, electrolysis time, and initial dye concentrations on the decolorization of Reactive Yellow 135 (RY 135) solutions and the treatment of a textile wastewater by electrocoagulation (EC) with aluminum electrodes were investigated separately. Total organic carbon (TOC) and dye removal ratios were used to measure the treatment efficiency. Energy and electrode consumptions were calculated per m3 of dye solution and per kg of pollutant removed. Amount of sludge produced after EC was also reported per m3 of dye solution. For a complete technical analysis, chemical coagulation experiments with aluminum salts were also carried out. Different direct and indirect cost items including energy, sacrificial electrodes, labor, sludge handling and disposal, maintenance, and depreciation costs have been considered in the calculation of the total operating cost. Under the optimum parameters found in this study, 0.23 $/m3 of total operating cost was acquired with 81% of COD, 85% of TOC, 93.7% of turbidity, and 97.1% of TSS removal efficiencies in treatment of the textile wastewater with EC. 0.11 kWh/m3 of energy and 0.03 kg/m3 of aluminum were consumed while 0.15 kg/m3 of sludge were produced in the process. (C) 2011 American Institute of Chemical Engineers Environ Prog, 2011
BibTeX:
@article{Yuksel2012,
  author = {Yuksel, E. and Gurbulak, E. and Eyvaz, M.},
  title = {Decolorization of a reactive dye solution and treatment of a textile wastewater by electrocoagulation and chemical coagulation: Techno-economic comparison},
  journal = {Environmental Progress & Sustainable Energy},
  year = {2012},
  volume = {31},
  number = {4},
  pages = {524--535},
  url = {://WOS:000310261600005},
  doi = {10.1002/ep.10574}
}
Akyol NH, Yolcubal I and Yuksel DI (2011), "Sorption and transport of trichloroethylene in caliche soil", Chemosphere. Vol. 82(6), pp. 809-816.
Abstract: Sorption of TCE to the caliche soil exhibited linear isotherm at the high TCE concentrations (Co = 122-1300 mg L(-1)) but Freundlich isotherm at the low concentration range (1-122 mg L(-1)). Sorption strength of the carbonate fraction of the soil was about 100-fold lower than the sorption strength of soil organic matter (SUM) in the caliche soil, indicating weak affinity of TCE for the carbonate fraction of the soil. Desorption of TCE from the caliche soil was initially rapid (7.6 x 10(-4) s(-1)), then continued at a 100-fold slower rate (7.7 x 10(-6) s(-1)). Predominant calcium carbonate fraction of the soil (96%) was responsible for the fast desorption of TCE while the SUM fraction (0.97%) controlled the rate-limited desorption of TCE. Transport of TCE in the caliche soil was moderately retarded with respect to the water (R = 1.75-2.95). Flow interruption tests in the column experiments indicated that the rate-limited desorption of TCE controlled the non-ideal transport of TCE in the soil. Modeling studies showed that both linear and non-linear nonequilibrium transport models provided reasonably good match to the TCE breakthrough curves (r(2) = 0.95-0.98). Non-linear sorption had a negligible impact on both the breakthrough curve shape and the values of sorption kinetics parameters at the high TCE concentration (Co = 1300 mg L(-1)). However, rate-limited sorption/desorption processes dominated at this concentration. For the low TCE concentration case (110 mg L(-1)), in addition to the rate-limited sorption/desorption, contribution of the non-linear sorption to the values of sorption kinetics became fairly noticeable. (C) 2010 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Akyol2011,
  author = {Akyol, N. H. and Yolcubal, I. and Yuksel, D. I.},
  title = {Sorption and transport of trichloroethylene in caliche soil},
  journal = {Chemosphere},
  year = {2011},
  volume = {82},
  number = {6},
  pages = {809--816},
  url = {://WOS:000287337800003},
  doi = {10.1016/j.chemosphere.2010.11.029}
}
Bektas N and Goksin I (2011), "Hazardous Waste Inventory in Gebze Organized Industrial Zone, Kocaeli, Turkey", Environmental Progress & Sustainable Energy. Vol. 30(3), pp. 409-415.
Abstract: Hazardous waste management (HWM) is one of the most important environmental problems. The lack of sufficient information on hazardous waste (HW) results in failure of the control and monitoring mechanisms. The HW is needed to be identified for an appropriate recovery and disposal strategy. Based on previous studies, the most important problem for effective HWM in Turkey is the lack of a reliable countrywide HW inventory. This insufficient information results in fewer recovery and recycling possibilities and also disposal facilities resulting in illegal and random release of HWs to the environment. A reliable and updated inventory study for waste type, source, and quantity information is required to determine and overcome this problem. The inventory information, such as generation of HW place, type, and collection will be the guide for the prevention, recovery, reuse, and also treatment of these wastes. The aim of this article is to describe a HW inventory study conducted in an organized industrial zone for a year. The inventory lists for HW were prepared on the basis of generation, types, and quantities of HW. (C) 2010 American Institute of Chemical Engineers Environ
BibTeX:
@article{Bektas2011,
  author = {Bektas, N. and Goksin, I.},
  title = {Hazardous Waste Inventory in Gebze Organized Industrial Zone, Kocaeli, Turkey},
  journal = {Environmental Progress & Sustainable Energy},
  year = {2011},
  volume = {30},
  number = {3},
  pages = {409--415},
  url = {://WOS:000295116200017},
  doi = {10.1002/ep.10498}
}
Bektas N, Aydin S and Oncel MS (2011), "The Adsorption of Arsenic Ions Using Beidellite, Zeolite, and Sepiolite Clays: A Study of Kinetic, Equilibrium and Thermodynamics", Separation Science and Technology. Vol. 46(6), pp. 1005-1016.
Abstract: Arsenic contamination in drinking water resources is a global problem; therefore, its removal from drinking water has become an important sustainable matter. The adsorption process can be more cost-effective and applicable, especially, if the absorbents used in the process are low-cost natural geo-materials. Beidellite, zeolite, and sepiolite are inexpensive and natural minerals available locally, modified, and used as adsorbents for the removal of arsenic ions from aqueous solutions in batch experiments. The kinetics of the adsorption process was separately tested for the pseudo-first order and pseudo-second order reactions and intra-particle diffusion models. The rate constants of adsorption for all these kinetic models were calculated. The comparison among the models showed that the pseudo second-order model best described the adsorption kinetics. Applied to the experimental equilibrium, at different temperatures were the Langmuir and Freundlich isotherm models. The Langmuir isotherm was used to calculate the adsorption capacities (Q degrees) of minerals for arsenic ions. The adsorption capacities of these three modified minerals, at different temperatures, ranged from 476 to 841 mu g/g. Thermodynamic studies showed that the arsenic uptake reactions by minerals were endothermic and spontaneous in nature. Bottled spring water containing arsenic, sold in markets, was used to conduct the arsenic adsorption study beidellite, zeolite, and sepiolite, minerals which efficiently removed the arsenate ions from the bottled drinking water. The use of modified beidellite, zeolite, and sepiolite as adsorbents in the arsenic ion removal processes is possible, based on the optimum parameters found.
BibTeX:
@article{Bektas2011a,
  author = {Bektas, N. and Aydin, S. and Oncel, M. S.},
  title = {The Adsorption of Arsenic Ions Using Beidellite, Zeolite, and Sepiolite Clays: A Study of Kinetic, Equilibrium and Thermodynamics},
  journal = {Separation Science and Technology},
  year = {2011},
  volume = {46},
  number = {6},
  pages = {1005--1016},
  url = {://WOS:000289583400015},
  doi = {10.1080/01496395.2010.534524}
}
Dizge N, Tansel B and Sizirici B (2011), "Process intensification with a hybrid system: A tubular packed bed bioreactor with immobilized activated sludge culture coupled with membrane filtration", Chemical Engineering and Processing. Vol. 50(8), pp. 766-772.
Abstract: Performance of a hybrid system consisting of a tubular bioreactor and a membrane filter was studied for removing carbohydrate and protein. Microporous polyurethane (sponge) was used as the packing medium for immobilization activated sludge culture. The bioreactor was operated in series with a cross flow ultrafiltration system to study the effect of influent flow rate and chemical oxygen demand (COD) concentration on the overall system performance. The removal efficiency in the bioreactor decreased linearly with increase in loading. The decline of removal efficiency at higher loadings was more significant for protein than carbohydrate. Coupling the bioreactor with a membrane separation process increased the overall removal rates and provided a consistent effluent quality. The flux through ultrafiltration membrane did not change significantly even when the bioreactor effluent had high levels of protein. Morphological examination of the packing medium both visually and by SEM showed significant accumulation of organisms on the surface which indicates that biofilm thickness was controlled by diffusion limitations. Advantages of the hybrid system include small footprint, economical packing medium, and space savings by coupling the bioreactor with a membrane filtration process. (C) 2011 Elsevier B.V. All rights reserved.
BibTeX:
@article{Dizge2011,
  author = {Dizge, N. and Tansel, B. and Sizirici, B.},
  title = {Process intensification with a hybrid system: A tubular packed bed bioreactor with immobilized activated sludge culture coupled with membrane filtration},
  journal = {Chemical Engineering and Processing},
  year = {2011},
  volume = {50},
  number = {8},
  pages = {766--772},
  url = {://WOS:000295504600006},
  doi = {10.1016/j.cep.2011.06.007}
}
Dizge N and Tansel B (2011), "Multiparametric investigation of competitive and noncompetitive sorption characteristics of SMP fractions (carbohydrate and protein) on activated carbon", Journal of Hazardous Materials. Vol. 185(2-3), pp. 996-1004.
Abstract: Sorption characteristics of soluble microbial products (SMPs) as carbohydrate and protein on activated carbon were investigated. Batch experiments were conducted to evaluate the sorption kinetics and the equilibrium conditions. The parameters studied included initial SMP concentration (50-200 mg/L), activated carbon dosage (0.25-50 g/L), contact time (0.02-4 h), particle size of activated carbon used (5-75 mu m, 75-850 mu m, and 850-1000 mu m), and presence of one or both SMP fractions. The equilibrium sorption of carbohydrate and protein were significantly affected by the presence of the second SMP fraction in the solutions. Adsorption isotherms were expressed by the Langmuir and Freundlich models. The adsorption rates under noncompetitive and competitive conditions were analyzed with kinetics-based Lagergren pseudo-first order and pseudo-second order models; and diffusion-based external diffusion and Weber-Morris intraparticle models. Both SMP fractions were removed effectively, however, sorption of protein was significantly better than that of carbohydrate in all cases. The relatively significant effect of particle size on sorption of protein indicates that protein is most likely adsorbed as a single layer on the carbon surface. For the carbohydrate, the increase in particle size did not decrease the sorption significantly indicating that carbohydrate may be adsorbed in multiple layers or may diffuse into the porous matrix more effectively. (C) 2010 Elsevier B.V. All rights reserved.
BibTeX:
@article{Dizge2011a,
  author = {Dizge, N. and Tansel, B.},
  title = {Multiparametric investigation of competitive and noncompetitive sorption characteristics of SMP fractions (carbohydrate and protein) on activated carbon},
  journal = {Journal of Hazardous Materials},
  year = {2011},
  volume = {185},
  number = {2-3},
  pages = {996--1004},
  url = {://WOS:000286782600058},
  doi = {10.1016/j.jhazmat.2010.10.004}
}
Dizge N, Soydemir G, Karagunduz A and Keskinler B (2011), "Influence of type and pore size of membranes on cross flow microfiltration of biological suspension", Journal of Membrane Science. Vol. 366(1-2), pp. 278-285.
Abstract: Pressure driven membrane processes have been substantially used for the separation of solids and liquid. The main disadvantage of such systems is rapid fouling, causing higher energy consumption and lower flux output. The main objective of this study was to explore the influences of type and pore size of membranes on bio-fouling by biological suspensions. Cellulose acetate, polyethersulfone, mixed ester, polycarbonate (CA, PES, ME, PC) membranes with three different pore sizes (0.40-0.45, 0.22, 0.10 mu m) were used in cross flow microfiltration experiments. The flux decline behavior was observed with time. Permeate samples were taken for protein and carbohydrate analysis. Surface roughness of clean and fouled membranes were determined using atomic force microscopy (AFM) images. CA membrane with pore size of 0.45 mu m showed the most rapid decline in the flux among all membranes due to its irregular and rough surface. ME membranes yielded the greatest steady state flux value followed by PC and PES, while CA membranes had the lowest steady state flux. PC membranes had the greatest pore resistance (R(p)) for membranes at all pore sizes. Concentration polarization was observed to be a significant fouling mechanism for all membranes. (C) 2010 Elsevier B.V. All rights reserved.
BibTeX:
@article{Dizge2011b,
  author = {Dizge, N. and Soydemir, G. and Karagunduz, A. and Keskinler, B.},
  title = {Influence of type and pore size of membranes on cross flow microfiltration of biological suspension},
  journal = {Journal of Membrane Science},
  year = {2011},
  volume = {366},
  number = {1-2},
  pages = {278--285},
  url = {://WOS:000285851600033},
  doi = {10.1016/j.memsci.2010.10.010}
}
Dizge N, Koseoglu-Imer DY, Karagunduz A and Keskinler B (2011), "Effects of cationic polyelectrolyte on filterability and fouling reduction of submerged membrane bioreactor (MBR)", Journal of Membrane Science. Vol. 377(1-2), pp. 175-181.
Abstract: Organic and inorganic polyelectrolytes are commonly used as coagulants or flocculants in membrane bioreactor to enhance the filtration properties of membranes. The main objective of this study was to determine the effectiveness of organic cationic polyelectrolyte (CPE) addition on filterability of various membranes and to investigate the influences on fouling of membranes. First, batch tests were performed to determine the optimum polyelectrolyte concentration at which the highest soluble microbial products (SMPs) removal was observed. Then, short-term filtration test were conducted. Cellulose acetate, polyethersulfone, mixed ester, polycarbonate (CA, PES, ME, PC) membranes with two different pore sizes (0.45-0.40 and 0.22-0.20 mu m) were used in submerged MBR experiments. Permeate flux decline at constant vacuum was observed with time. Protein and carbohydrate analysis were performed in the permeate samples. Filtration resistances were determined for each membrane. Cake resistance was observed to be the most significant fouling mechanism for all membranes. Polyelectrolyte addition decreased the cake resistance. The effect of polyelectrolyte on pore resistance was relatively insignificant. The results showed that addition of polyelectrolyte had significant impact on sustainable filtration time. (C) 2011 Elsevier By. All rights reserved.
BibTeX:
@article{Dizge2011c,
  author = {Dizge, N. and Koseoglu-Imer, D. Y. and Karagunduz, A. and Keskinler, B.},
  title = {Effects of cationic polyelectrolyte on filterability and fouling reduction of submerged membrane bioreactor (MBR)},
  journal = {Journal of Membrane Science},
  year = {2011},
  volume = {377},
  number = {1-2},
  pages = {175--181},
  url = {://WOS:000292580000017},
  doi = {10.1016/j.memsci.2011.04.048}
}
Engin GO, Ucar BS and Senturk E (2011), "Reuse feasibility of pre-treated grey water and domestic wastewater with a compact household reverse osmosis system", Desalination and Water Treatment. Vol. 29(1-3), pp. 103-109.
Abstract: Many countries in the Mediterranean basin are facing water shortage issues. Since water is becoming a rare resource, grey water and domestic wastewater reuse arises as a sustainable solution to reduce the overall water demand. In this study, a compact household reverse osmosis unit was used in order to determine the feasibility of pre-treated grey water and domestic wastewater reuse. The preliminary studies revealed that the compact system used was able to treat the wastewaters studied with quite high organic matter and nutrient removal efficiencies. For pre-treated grey water, the COD and BOD removal rates were around 80%. For pre-treated domestic wastewater, the organic matter removal rates were higher. In addition, soluble nutrients, such as nitrate and phosphate were also studied. The conductivity of permeate was reduced to 15 mu S/cm and 55 mu S/cm for grey water and domestic wastewater, respectively, within 15 min. The permeate obtained was free of suspended solids and had an excellent physical appearance. The overall results indicated that the product can be used for gardening, fire hydrants, field irrigation, or alternatively for toilet flushing after disinfection.
BibTeX:
@article{Engin2011,
  author = {Engin, G. O. and Ucar, B. S. and Senturk, E.},
  title = {Reuse feasibility of pre-treated grey water and domestic wastewater with a compact household reverse osmosis system},
  journal = {Desalination and Water Treatment},
  year = {2011},
  volume = {29},
  number = {1-3},
  pages = {103--109},
  url = {://WOS:000291314400012},
  doi = {10.5004/dwt.2011.2155}
}
Ergenekon P, Gurbulak E and Keskinler B (2011), "A novel method for sulfonation of microporous polystyrene divinyl benzene copolymer using gaseous SO2 in the waste air streams", Chemical Engineering and Processing. Vol. 50(1), pp. 16-21.
Abstract: In this study a novel sulfonation method for microporous polystyrene divinyl benzene copolymer (PSDBP) was introduced. In our sulfonation system gaseous SO2 is used as the sulfonation agent and planned to be obtained from waste gas streams. The proposed method, therefore, combines SO2 control and clean sulfonation technology in a single compact design. Molded polymeric monoliths of the PSDBP containing imprisoned H2O2 solution inside the pores (PSDBPH2O2) were produced in disk shapes. Dry gas mixture containing 3000 ppm SO2 is fed into PSDBPH2O2 disk reactor with a flow rate of 0.8 L/min and effluent gas composition in terms of SO2 was measured. Breakthrough curves for varied initial H2O2 amount were used to calculate SO2 adsorption capacity and sulfonation degree of the PSDBPH2O2 disks. Successful sulfonation of PSDBPH2O2 was verified by the changes in its morphological structure and formed sulfone bonds determined by SEM and IR analyses. respectively. Maximum adsorption capacity for PSDBPH2O2 for the initial H2O2 volume percentage of 13% was determined as 57 mg SO2/g polymer. It should be noted that SO2 adsorption was observed only in H2O2 imprisoned polymer disks. Sulfonation degree of PSDBPH2O2 which attained maximum SO2 amount is calculated as 10%. (C) 2010 Elsevier B.V. All rights reserved.
BibTeX:
@article{Ergenekon2011,
  author = {Ergenekon, P. and Gurbulak, E. and Keskinler, B.},
  title = {A novel method for sulfonation of microporous polystyrene divinyl benzene copolymer using gaseous SO2 in the waste air streams},
  journal = {Chemical Engineering and Processing},
  year = {2011},
  volume = {50},
  number = {1},
  pages = {16--21},
  url = {://WOS:000287903000003},
  doi = {10.1016/j.cep.2010.10.009}
}
Eyvaz M, Aktas TS, Yuksel E and Saatci AM (2011), "Effects of intermittent polyelectrolyte addition on water quality in direct filtration", Water Quality Research Journal of Canada. Vol. 46(1), pp. 52-63.
Abstract: The effects of intermittent polyelectrolyte addition on the quality of effluent water and on the development of filter headloss were studied. Anionic and cationic polyelectrolytes were applied to two similarly constructed pilot sand filters. The surface water used in the study was obtained from Omerli, which is one of the main drinking water reservoirs of Istanbul. Six sets of experiments were carried out. The objective of the experiments in the first three sets was to determine the type and dose of suitable polyelectrolyte. The polyelectrolytes were then added intermittently and continuously in the last three sets. Intermittent addition of polyelectrolyte produced better effluent quality and reduced the polyelectrolyte consumption by half with much less headloss. Ives' Filterability Index, which incorporates the important filtration design parameters such as effluent quality, the headloss and the velocity of filtration into a dimensionless number, was used for the comparison of the experimental results.
BibTeX:
@article{Eyvaz2011,
  author = {Eyvaz, M. and Aktas, T. S. and Yuksel, E. and Saatci, A. M.},
  title = {Effects of intermittent polyelectrolyte addition on water quality in direct filtration},
  journal = {Water Quality Research Journal of Canada},
  year = {2011},
  volume = {46},
  number = {1},
  pages = {52--63},
  url = {://WOS:000295029800006},
  doi = {10.2166/wqrjc.2011.016}
}
Herand BK, Oncel S and Ozkan M (2011), "Bioremoval of heavy metals from synthetic waste water by local bacterial isolates immobilized on polymeric matrix", Current Opinion in Biotechnology. Vol. 22, pp. S72-S72.
BibTeX:
@article{Herand2011,
  author = {Herand, B. K. and Oncel, S. and Ozkan, M.},
  title = {Bioremoval of heavy metals from synthetic waste water by local bacterial isolates immobilized on polymeric matrix},
  journal = {Current Opinion in Biotechnology},
  year = {2011},
  volume = {22},
  pages = {S72-S72},
  url = {://WOS:000295310800203},
  doi = {10.1016/j.copbio.2011.05.208}
}
Imer-Koseoglu DY, Karagunduz A and Keskinler B (2011), "Fouling characteristics of microfiltration membranes during the filtration of jet loop membrane bioreactor (JLMBR) activated sludge", Desalination and Water Treatment. Vol. 26(1-3), pp. 124-130.
Abstract: The main objective of this study was to characterize the activated sludge of jet loop membrane bioreactor (JLMBR) in order to determine its effects on the membrane biofouling. The sludge characteristics were evaluated in terms of MLSS (mixed liquor suspended solid), EPS (extracellular polymeric substance), SMP (soluble microbial product), relative hydrophicity (RH) and viscosity. The membrane filtration tests were performed at a cross-flow microfiltration system by using cellulose acetate (CA) and cellulose nitrate (CN) filters with 0.2 and 0.45 mu m of pore sizes. The jet loop bioreactor was operated at a batch mode for 36 d with an organic load of 3 kg COD m(-3)d(-1). The COD treatment efficiency was achieved at 95%. It was found that the sludge properties changed with MLSS concentration. The viscosity of sludge increased and the RH of sludge decreased with increase in MLSS concentration. The EPS concentration of the sludge was much higher than SMP concentration. The carbohydrate contents of EPS and SMP were higher than the protein contents. The flux decline models and the resistance analysis were used to investigate the biofouling mechanism. In the resistance analysis, it was found that the pore blocking resistance (R(p)) of CA membrane with pore size of 0.45 mu m (CA045) was higher than the cake layer resistance (R(c)), (3.56 and 1.02 x 10(12) m(-1)). R c was more higher than R(p) for the other membranes. R(p) of membranes were found to be 33.6%, 77.1%, 23.4% and 21.9% of the total resistances (R(t)) for CA02, CA045, CN02 and CN045, respectively. It was concluded that the high EPS content in JLMBR was the main fouling parameter for membranes. It was also found that the affinity of membrane types against EPS varied.
BibTeX:
@article{Imer-Koseoglu2011,
  author = {Imer-Koseoglu, D. Y. and Karagunduz, A. and Keskinler, B.},
  title = {Fouling characteristics of microfiltration membranes during the filtration of jet loop membrane bioreactor (JLMBR) activated sludge},
  journal = {Desalination and Water Treatment},
  year = {2011},
  volume = {26},
  number = {1-3},
  pages = {124--130},
  url = {://WOS:000287816400018},
  doi = {10.5004/dwt.2011.2121}
}
Karagoz P and Ozkan M (2011), "Cellulolytic activities of ethanol producing anaerobic bacteria: clostridium thermocellum and a novel isolate", Febs Journal. Vol. 278, pp. 152-152.
BibTeX:
@article{Karagoz2011,
  author = {Karagoz, P. and Ozkan, M.},
  title = {Cellulolytic activities of ethanol producing anaerobic bacteria: clostridium thermocellum and a novel isolate},
  journal = {Febs Journal},
  year = {2011},
  volume = {278},
  pages = {152--152},
  url = {://WOS:000292333101249}
}
Kobya M, Ulu F, Gebologlu U, Demirbas E and Oncel MS (2011), "Treatment of potable water containing low concentration of arsenic with electrocoagulation: Different connection modes and Fe-Al electrodes", Separation and Purification Technology. Vol. 77(3), pp. 283-293.
Abstract: In this study, effects of both Fe and Al electrode connection modes (parallel and series) and electrode materials on arsenic removal efficiency from potable water by electrocoagulation (EC) process were investigated. Experiments were carried out to remove arsenic by the EC covering wide range in operating conditions such as pH (4-9), current density (1.75-7.5 A/m(2)) and operating time (0-15 min). The highest arsenic removal was obtained in the monopolar series (MP-S) electrode connection mode for both electrodes as pH 6.5 for Fe and pH 7 for Al electrodes to achieve a residual arsenic concentration of 10 mu g/L or less for potable water in the EC process. As the current density increased, arsenic removal efficiencies were increased with all types of electrode connection modes. However, the optimum arsenic removal at 2.5 A/m(2) was obtained with 2.5 min of operating time for Fe (94.1%) and 4 min of operating time (93.5%) for Al electrodes at MP-S mode. The electrode and energy consumption values at MP-S connection mode for Fe and Al electrodes were calculated as 0.00140 kg Fe/m(3) and 0.0025 kg Al/m(3), and 0.0140 kWh/m(3) and 0.0254 kWh/m(3), respectively. Therefore, the lowest operating costs were 0.0047 epsilon/m(3) and 0.0064 epsilon/m(3) for Fe and Al electrodes. The optimum arsenic removal from potable water by the EC process showed that Fe electrodes gave the best results at MP-S connection mode as compared to the rest in terms of operating time and operating cost. The sludge was analyzed using scanning electron microscope (SEM) imaging. The SEM image suggested that amorphous Fe/Al oxyhydroxides were present in the sludge. (C) 2010 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kobya2011,
  author = {Kobya, M. and Ulu, F. and Gebologlu, U. and Demirbas, E. and Oncel, M. S.},
  title = {Treatment of potable water containing low concentration of arsenic with electrocoagulation: Different connection modes and Fe-Al electrodes},
  journal = {Separation and Purification Technology},
  year = {2011},
  volume = {77},
  number = {3},
  pages = {283--293},
  url = {://WOS:000288738500002},
  doi = {10.1016/j.seppur.2010.12.018}
}
Kobya M, Gebologlu U, Ulu F, Oncel S and Demirbas E (2011), "Removal of arsenic from drinking water by the electrocoagulation using Fe and Al electrodes", Electrochimica Acta. Vol. 56(14), pp. 5060-5070.
Abstract: A novel technique of electrocoagulation (EC) was attempted in the present investigation to remove arsenic from drinking waters. Experiments were carried out in a batch electrochemical reactor using Al and Fe electrodes with monopolar parallel electrode connection mode to assess their efficiency. The effects of several operating parameters on arsenic removal such as pH (4-9), current density (2.5-7.5 A m(-2)), initial concentration (75-500 mu g L-1) and operating time (0-15 min) were examined. Optimum operating conditions were determined as an operating time of 12.5 min and pH 6.5 for Fe electrode (93.5%) and 15 min and pH 7 for Al electrode (95.7%) at 2.5 A m(-2), respectively. Arsenic removal obtained was highest with Al electrodes. Operating costs at the optimum conditions were calculated as 0.020 (sic) m(-3) for Fe and 0.017 (sic) m(-3) for Al electrodes. EC was able to bring down aqueous phase arsenic concentration to less than 10 mu g L-1 with Fe and Al electrodes. The adsorption of arsenic over electrochemically produced hydroxides and metal oxide complexes was found to follow pseudo second-order adsorption model. Scanning electron microscopy was also used to analyze surface topography of the solid particles at Fe/Al electrodes during the EC process. (C) 2011 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Kobya2011a,
  author = {Kobya, M. and Gebologlu, U. and Ulu, F. and Oncel, S. and Demirbas, E.},
  title = {Removal of arsenic from drinking water by the electrocoagulation using Fe and Al electrodes},
  journal = {Electrochimica Acta},
  year = {2011},
  volume = {56},
  number = {14},
  pages = {5060--5070},
  url = {://WOS:000291907300020},
  doi = {10.1016/j.electacta.2011.03.086}
}
Kobya M, Demirbas E, Bayramoglu M and Sensoy MT (2011), "Optimization of Electrocoagulation Process for the Treatment of Metal Cutting Wastewaters with Response Surface Methodology", Water Air and Soil Pollution. Vol. 215(1-4), pp. 399-410.
Abstract: In the present investigation, treatment of metal cutting wastewater (MCW) using electrocoagulation (EC) process is designed and analyzed using response surface methodology (RSM). RSM is applied to optimize the operating variables viz. initial pH, current density, and operating time on the treatment of MCW in a batch mode by EC process using iron and aluminum electrodes. Quadratic models are developed for the responses such as chemical oxygen demand (COD), total organic carbon (TOC), and turbidity, and operating cost is calculated with respect to energy, electrode, and chemical consumptions. The actual COD, TOC, and turbidity removal efficiencies at optimized conditions are found to be 93.0%, 83.0%, and 99.8% for Fe electrode and 93.5%, 85.2%, and 99.9% for Al electrode, respectively, which agree well with the predicted response. The proposed model fits very well with the experimental data with R (2) adjusted correlation coefficients of 0.927 for COD, 0.924 for TOC, and 0.968 for turbidity removal for Al and 0.904 for COD, 0.976 for TOC, and 0.989 for turbidity removal for Fe electrodes, respectively. This study clearly shows that RSM is one of the suitable methods to optimize the operating conditions and maximize the COD, TOC, and turbidity removal efficiencies for both electrodes while keeping the operating costs to minimal (0.371 a,not sign/m(3) for Fe and 0.337 a,not sign/m(3) for Al electrodes).
BibTeX:
@article{Kobya2011b,
  author = {Kobya, M. and Demirbas, E. and Bayramoglu, M. and Sensoy, M. T.},
  title = {Optimization of Electrocoagulation Process for the Treatment of Metal Cutting Wastewaters with Response Surface Methodology},
  journal = {Water Air and Soil Pollution},
  year = {2011},
  volume = {215},
  number = {1-4},
  pages = {399--410},
  url = {://WOS:000286195800032},
  doi = {10.1007/s11270-010-0486-x}
}
Koseoglu-Imer DY, Dizge N, Karagunduz A and Keskinler B (2011), "Influence of membrane fouling reducers (MFRs) on filterability of disperse mixed liquor of Jet Loop Bioreactors", Bioresource Technology. Vol. 102(13), pp. 6843-6849.
Abstract: The effects of membrane fouling reducers (MFRs) (the cationic polyelectrolyte (CPE) and FeCl(3)) on membrane fouling were studied in a lab-scale jet loop submerged membrane bioreactor (JL-SMBR) system. The optimum dosages of MFRs (CPE dosage = 20 mg g(-1) MLSS, FeCl(3) dosage = 14 mg g(-1) MLSS) were continuously fed to JL-SMBR system. The soluble and bound EPS concentrations as well as MLSS concentration in the mixed liquor of JL-SMBR were not changed substantially by the addition of MFRs. However, significant differences were observed in particle size and relative hydrophobicity. Filtration tests were performed by using different membrane types (polycarbonate (PC) and nitrocellulose mixed ester (ME)) and various pore sizes (0.45-0.22-0.1 mu m). The steady state fluxes (J(ss)) of membranes increased at all membranes after MFRs addition to JL-SMBR. The filtration results showed that MFRs addition was an effective approach in terms of improvement in filtration performance for both membrane types. (C) 2011 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Koseoglu-Imer2011,
  author = {Koseoglu-Imer, D. Y. and Dizge, N. and Karagunduz, A. and Keskinler, B.},
  title = {Influence of membrane fouling reducers (MFRs) on filterability of disperse mixed liquor of Jet Loop Bioreactors},
  journal = {Bioresource Technology},
  year = {2011},
  volume = {102},
  number = {13},
  pages = {6843--6849},
  url = {://WOS:000292487300009},
  doi = {10.1016/j.biortech.2011.04.024}
}
Kunt ED, Naskali AT, Khalil ISM, Sabanovic A and Yuksel E (2011), "Design and development of workstation for microparts manipulation and assembly", Turkish Journal of Electrical Engineering and Computer Sciences. Vol. 19(6), pp. 973-992.
Abstract: In this paper, microassembly system design issues are discussed with requirements, constraints and necessities for the development of an assembly platform, and these issues are shown over a versatile and reconfigurable microassembly workstation which is designed and realized as a research tool for investigation of the problems in microassembly and micromanipulation tasks. First prototype of a workstation and the development of a second prototype with enhancements on mechanical and control structure of the system are presented with details on the configuration of the systems. In addition, several experiments using a workstation are presented both on the first and the second prototypes in different modes of operation such as tele-operated, semi-automated and fully automated by means of visual feedback.
BibTeX:
@article{Kunt2011,
  author = {Kunt, E. D. and Naskali, A. T. and Khalil, I. S. M. and Sabanovic, A. and Yuksel, E.},
  title = {Design and development of workstation for microparts manipulation and assembly},
  journal = {Turkish Journal of Electrical Engineering and Computer Sciences},
  year = {2011},
  volume = {19},
  number = {6},
  pages = {973--992},
  url = {://WOS:000295497900012},
  doi = {10.3906/elk-1005-566}
}
Ozoner SK, Yilmaz F, Celik A, Keskinler B and Erhan E (2011), "A novel poly(glycine methacrylate-co-3-thienylmethyl methacrylate)-polypyrrole-carbon nanotube-horseradish peroxidase composite film electrode for the detection of phenolic compounds", Current Applied Physics. Vol. 11(3), pp. 402-408.
Abstract: A novel amperometric biosensor, based on poly(glycine methacrylate-co-3-thienylmethyl methacrylate)polypyrrole-carbon nanotube Poly(GMA-co-MTM)/PPy/CHT composite matrix, was used for the determination of eighteen phenol derivatives. The enzyme, horseradish peroxidase (HRP) was covalently immobilized to this novel composite polymer matrix. The measurement of the phenolic compounds was carried out by the electrode reduction of the generated phenoxy radical, product of the enzymatic reaction, at a fixed voltage of 50 mV. Optimization of the experimental parameters was performed with regard to pH, operational potential and hydrogen peroxide concentration. The differences in sensitivity, linear range, detection limit and response time observed for series of phenolic compounds were discussed. The biosensor gave no response to m-cresol, o-cresol and p-cresol. Poly(GMA-co-MTM)/PPy/CNT/HRP composite film electrode retained 80% of its initial activity after the usage of 700 measurements in one month. (C) 2010 Elsevier B.V. All rights reserved.
BibTeX:
@article{Ozoner2011,
  author = {Ozoner, S. K. and Yilmaz, F. and Celik, A. and Keskinler, B. and Erhan, E.},
  title = {A novel poly(glycine methacrylate-co-3-thienylmethyl methacrylate)-polypyrrole-carbon nanotube-horseradish peroxidase composite film electrode for the detection of phenolic compounds},
  journal = {Current Applied Physics},
  year = {2011},
  volume = {11},
  number = {3},
  pages = {402--408},
  url = {://WOS:000288183300024},
  doi = {10.1016/j.cap.2010.08.010}
}
Ozoner SK, Keskinler B and Erhan E (2011), "HRP immobilized microporous Poly(styrene-divinylbenzene-polyglutaraldehyde) monolith for forced flow injected phenol biosensing", Materials Science & Engineering C-Materials for Biological Applications. Vol. 31(3), pp. 663-668.
Abstract: A colorimetric detection system based on horseradish peroxidase (HRP) immobilized microporous Poly (styrene-divinylbenzene-polyglutaraldehyde) monolith was developed for phenol biosensing. The incorporation of the aldehyde groups to the backbone of the microporous (90%) monolith was achieved by the polymerization of the continuous phase of a high internal phase emulsion. HRP was chemically immobilized onto the inner walls of the micropores of the monolith via the aldehyde groups. HRP immobilized microporous monolith (HRP-MM) was used as a biocatalytic cell under forced flow conditions in a flow injection system. A carrier stream containing 4-aminoantipyrine (4-AAP) as color reagent was flowed through the HRP-MM at various flow rates ranged between 0.1-15 mL min(-1). The analytical parameters of response time, detection limit and linear range varied at the range of 1-60 s, 1-250 mu M, and 0.25-2 mM, respectively. The results showed that the most accurate phenol biosensing was obtained at the flow rate of 1 mL min(-1). The microarchitected structure of the monolith improved the mass transferring conditions for the enzymatic reaction due to the forced flow through the micropores. The detection system presented a satisfactory precision evaluated by relative standard deviation of 1.1% (n = 13) and recovery of 100% at the flow rate of 1 mL min(-1). The system showed 60% of its initial signal from 12th day up to the two months. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
BibTeX:
@article{Ozoner2011a,
  author = {Ozoner, S. K. and Keskinler, B. and Erhan, E.},
  title = {HRP immobilized microporous Poly(styrene-divinylbenzene-polyglutaraldehyde) monolith for forced flow injected phenol biosensing},
  journal = {Materials Science & Engineering C-Materials for Biological Applications},
  year = {2011},
  volume = {31},
  number = {3},
  pages = {663--668},
  url = {://WOS:000288045600023},
  doi = {10.1016/j.msec.2010.12.018}
}
Sulak MT and Keskinler B (2011), "DETECTION OF MALATHION USING A CARBON NANOTUBE MODIFIED GOLD ELECTRODE", Fresenius Environmental Bulletin. Vol. 20(10A), pp. 2744-2749.
Abstract: We developed a simple strategy for designing a sensitive electrochemical biosensor for organophosphate insecticides (OIs), based on an acetylcholinesterase (AChE)-carbon nanotube (CNT)-polypyrrole (PPy) biocomposite film modified gold electrode (labeled as AChE-CNT-PPy/Au). Based on the inhibition of OIs to the enzymatic activity of AChE, using malathion as a model compound, the conditions for detection of the insecticides were explored. The proposed method demonstrates an easy electron transfer between the immobilized enzyme and the electrode via functionalized CNTs in a polypyrrole matrix. Under optimal conditions, the inhibition of malathion was proportional to its concentration from 1.0-20.0 mu M. The detection limit was 0.1 mu M, with a good precision (RSD = 4.7 %, n = 8). The developed biosensor exhibited good stability. This method could be developed as a conventional one to select efficient enzyme inhibitors and investigate toxic compounds against enzymes.
BibTeX:
@article{Sulak2011,
  author = {Sulak, M. T. and Keskinler, B.},
  title = {DETECTION OF MALATHION USING A CARBON NANOTUBE MODIFIED GOLD ELECTRODE},
  journal = {Fresenius Environmental Bulletin},
  year = {2011},
  volume = {20},
  number = {10A},
  pages = {2744--2749},
  url = {://WOS:000296690500014}
}
Tan I, Erhan E, Karagoz P and Ozkan M (2011), "Determination of mercury and nickel by amperometric biosensor prepared with thermostable lactate dehydrogenase", Transactions of Nonferrous Metals Society of China. Vol. 21(10), pp. 2332-2338.
Abstract: Response of biosensor prepared with the thermostable bacterial LDH enzyme was analyzed in the presence of mercury and nickel. For electrode preparation, the enzyme was purified and immobilized on a gold sheet coated by PGA-pyrrole polymeric material. The working electrode was tested at increasing concentration of lactate in the presence of two different concentrations of mercury and nickel. Current response of biosensor decreased from 0.32 mu A to 0.09 mu A and 4.13 mu A to 2.63 mu A when 25x10(-7) mmol/L mercury and 17x10(-5) mmol/L nickel were included in the working solution, respectively. Sensitivity of the electrode decreased from 0.010 2 mu A/(mmol.L(-1)) to 0.0043 mu A/(mmol.L(-1)) in the presence of 25x10(-7) mmol/L mercury. On the other hand, the presence of nickel did not result in a decrease in electrode sensitivity. The results pointed out that the prepared biosensor is useful to detect mercury in a sample containing both mercury and nickel together.
BibTeX:
@article{Tan2011,
  author = {Tan, I. and Erhan, E. and Karagoz, P. and Ozkan, M.},
  title = {Determination of mercury and nickel by amperometric biosensor prepared with thermostable lactate dehydrogenase},
  journal = {Transactions of Nonferrous Metals Society of China},
  year = {2011},
  volume = {21},
  number = {10},
  pages = {2332--2338},
  url = {://WOS:000296916100034},
  doi = {10.1016/s1003-6326(11)61017-0}
}
Tansel B and Dizge N (2011), "Multi objective performance analysis of nanofiltration process to loading parameters by response surface approach", Desalination. Vol. 272(1-3), pp. 164-169.
Abstract: Response surface analysis was used to investigate membrane performance in relation to operating variables for removing zinc by nanofiltration. The control variables were selected as transmembrane pressure (2 and 4 bars), membrane type (NF 90 and NF 270), and zinc concentration in the feed solution (10.250 and 500 mg/L). Effects and interactions of the control variables were investigated in relation to quality of permeate, total membrane resistance, and the overall process performance, which was defined as the product of zinc concentration and total membrane resistance. The system performance was also evaluated in relation to membrane stress, which was defined as the product of influent zinc concentration and transmembrane pressure. The response surfaces, visualized by 3D graphics, show that there are optimum conditions for each membrane when system performance was defined to improve both the permeate quality and maintain a high flux level. The response surface equations provided relative significance of the variables on the membrane performances for the NF 90 membrane and the more permeable NF 270 membrane in terms of effluent quality, percent rejection, and membrane resistance. (C) 2011 Elsevier B.V. All rights reserved.
BibTeX:
@article{Tansel2011,
  author = {Tansel, B. and Dizge, N.},
  title = {Multi objective performance analysis of nanofiltration process to loading parameters by response surface approach},
  journal = {Desalination},
  year = {2011},
  volume = {272},
  number = {1-3},
  pages = {164--169},
  url = {://WOS:000289708200020},
  doi = {10.1016/j.desal.2011.01.012}
}
Tansel B and Dizge N (2011), "Competitive effects and interactions during sorption of SMP fractions on activated carbon: Response surface approach for visualization of sorption profiles", Journal of Environmental Management. Vol. 92(3), pp. 596-602.
Abstract: The objectives of this study were to investigate the significance of the effects and interactions for during competitive sorption of soluble microbial products (SMP). Batch experiments were conducted to assess the competitive sorption characteristics and individual affinity of glucose (carbohydrate) and bovine serum albumin (BSA) (protein) as two representative fractions of SMR The influence of surface availability was investigated by using carbon particles with different particle sizes (5-75 mu m, 75-850 mu m, and 850-1000 mu m) and different carbon amounts. Competitive effects and interactions were evaluated for each adsorbate and surface availability. Competitive sorption mechanisms were quantified in relation to surface affinity of the SMP fractions. Sorption capacity profiles of the SMP fractions at equilibrium were developed using second-degree polynomial models for the experimental data and compared with the estimates obtained from the modified Langmuir-like model which uses single parameter sorption data to estimate competitive sorption profiles of systems with two adsorbates. Adequacy limitations of the modified Langmuir-like model for each SMP fraction were evaluated based on the significance of the synergistic and antagonistic effects between the two SMP fractions and the carbon surface availability. (C) 2010 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Tansel2011a,
  author = {Tansel, B. and Dizge, N.},
  title = {Competitive effects and interactions during sorption of SMP fractions on activated carbon: Response surface approach for visualization of sorption profiles},
  journal = {Journal of Environmental Management},
  year = {2011},
  volume = {92},
  number = {3},
  pages = {596--602},
  url = {://WOS:000286782400025},
  doi = {10.1016/j.jenvman.2010.09.027}
}
Unsal M and Keskinler B (2011), "NON-AQUEOUS PURIFICATION OF BIODIESEL USING POLYETHYLENE GLYCOL 300", Fresenius Environmental Bulletin. Vol. 20(5A), pp. 1245-1251.
Abstract: According to the European Standard EN 14214, biodiesel fuels must have significant purity values; therefore, a post transesterification purification process is required to produce the fuel that fulfills the standard. Until recently, water washing was conventionally preferred as a biodiesel purification method. In this study, upon completion of the two parallel transesterification reactions, one of the reaction mixtures was washed with water and the other one with polyethylene glycol 300 (PEG 300), a flocculation agent, under several concentration conditions in order to compare two different purification methods, and which of them obtains better results. The features of biodiesel washed with PEG 300 were found to be similar to those of the other. Moreover, washing with PEG 300 was found to provide less glycerol precipitation time than conventional glycerol decantation. This process provided easy production of fatty acid alkyl esters without acid neutralization and deionized water-washing procedures that were necessary to produce a high-purity product onto the conventional transesterification process. The new washing process enabled low-cost production of the biodiesel from refined vegetables.
BibTeX:
@article{Unsal2011,
  author = {Unsal, M. and Keskinler, B.},
  title = {NON-AQUEOUS PURIFICATION OF BIODIESEL USING POLYETHYLENE GLYCOL 300},
  journal = {Fresenius Environmental Bulletin},
  year = {2011},
  volume = {20},
  number = {5A},
  pages = {1245--1251},
  url = {://WOS:000291083400003}
}
Yucel Y, Demir C, Dizge N and Keskinler B (2011), "Lipase immobilization and production of fatty acid methyl esters from canola oil using immobilized lipase", Biomass & Bioenergy. Vol. 35(4), pp. 1496-1501.
Abstract: Lipase enzyme from Aspergillus oryzae (EC 3.1.1.3) was immobilized onto a micro porous polymeric matrix which contains aldehyde functional groups and methyl esters of long chain fatty acids (biodiesel) were synthesized by transesterification of crude canola oil using immobilized lipase. Micro porous polymeric matrix was synthesized from styrene divinylbenzene (STY-DVB) copolymers by using high internal phase emulsion technique and two different lipases, Lipozyme TL-100L (R) and Novozym 388 (R), were used for immobilization by both physical adsorption and covalent attachment. Biodiesel production was carried out with semi-continuous operation. Methanol was added into the reactor by three successive additions of 1:4 M equivalent of methanol to avoid enzyme inhibition. The transesterification reaction conditions were as follows: oil/alcohol molar ratio 1:4; temperature 40 degrees C and total reaction time 6 h. Lipozyme TL-100L (R) lipase provided the highest yield of fatty acid methyl esters as 92%. Operational stability was determined with immobilized lipase and it indicated that a small enzyme deactivation occurred after used repeatedly for 10 consecutive batches with each of 24 h. Since the process is yet effective and enzyme does not leak out from the polymer, the method can be proposed for industrial applications. (C) 2010 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Yucel2011,
  author = {Yucel, Y. and Demir, C. and Dizge, N. and Keskinler, B.},
  title = {Lipase immobilization and production of fatty acid methyl esters from canola oil using immobilized lipase},
  journal = {Biomass & Bioenergy},
  year = {2011},
  volume = {35},
  number = {4},
  pages = {1496--1501},
  url = {://WOS:000289611400012},
  doi = {10.1016/j.biombioe.2010.12.018}
}
Yuksel E, Eyvaz M, Aktas TS and Saatci AM (2011), "A New Polyelectrolyte Dosing Method: Injection into Deep Bed Filter Media", Clean-Soil Air Water. Vol. 39(8), pp. 750-758.
Abstract: The aim of this paper was to investigate a novel method of polyelectrolyte injection into deep bed filter media. The raw water and the filter media used in the pilot filters were obtained from the Omerli Reservoir that supplies one million m(3)/day of water to the greater city of Istanbul. A cationic polyelectrolyte was injected at the entrance of the filter and at different depths of the sand bed. The effect of polyelectrolyte injection location and method was evaluated by measuring the effluent turbidity, effluent particle count, and the head losses at different locations of the sand media. It was observed that the simultaneous injection of the polyelectrolyte on top of the filter bed and at the center can lengthen the filter run time while achieving an effluent turbidity as low as 0.06 NTU (nephelometric turbidity unit) and 4 log (99.99%) particle removal.
BibTeX:
@article{Yuksel2011,
  author = {Yuksel, E. and Eyvaz, M. and Aktas, T. S. and Saatci, A. M.},
  title = {A New Polyelectrolyte Dosing Method: Injection into Deep Bed Filter Media},
  journal = {Clean-Soil Air Water},
  year = {2011},
  volume = {39},
  number = {8},
  pages = {750--758},
  url = {://WOS:000294720700006},
  doi = {10.1002/clen.201000277}
}
Akyol A and Bayramoglu M (2010), "Preparation and characterization of supported ZnO photocatalyst by zincate method", Journal of Hazardous Materials. Vol. 175(1-3), pp. 484-491.
Abstract: Supported ZnO film photocatalysts are prepared on glass and ceramic substrates by zincate method. Prepared ZnO films are seen rather strongly durable. They resist to chemical dissolution in a broad range of pH from 3 to 10. Various physical tests are conducted to measure the relevant characteristics of the films. Band gap of ZnO film is Calculated as 3.24eV. SEM analysis shows that the ZnO film has granular morphology with uniform particle size about 300-400 nm. The film thickness is calculated as 1.41 mu m after twenty coating cycles and the thickness of the thin film per cycle was approximately 70 turn. Photochemical activity tests are performed by measuring photodecolorization rate of methyl orange solution. First order rate constants are correlated to principal process parameters. The results show that ceramic is the preferable supporting material with high activity. According to simulation study, the photocatalytic activity of film coated on ceramic ring of 8 mm diameter is nearly equal to the activity of powder ZnO slurry of 120 mg/dm(3) density. It carried out about decolorization 65% in 3 h. The calculations show that it is possible to prepare ZnO film on ceramic ring with similar activity as powder ZnO. (C) 2009 Elsevier B.V. All Fights reserved.
BibTeX:
@article{Akyol2010,
  author = {Akyol, A. and Bayramoglu, M.},
  title = {Preparation and characterization of supported ZnO photocatalyst by zincate method},
  journal = {Journal of Hazardous Materials},
  year = {2010},
  volume = {175},
  number = {1-3},
  pages = {484--491},
  url = {://WOS:000274490400060},
  doi = {10.1016/j.jhazmat.2009.10.031}
}
Akyol A and Bayramoglu M (2010), "Photocatalytic performance of ZnO coated tubular reactor", Journal of Hazardous Materials. Vol. 180(1-3), pp. 466-473.
Abstract: The recovery of photocatalyst particles constitutes a serious drawback of slurry reactors. Therefore, depositing the catalyst mass on a suitable support without loss of photocatalytic activity is of practical importance. In this study, a chemical deposition method was applied to coat the inner surface of quartz tubes of various diameters with thin ZnO film. The method is economical, energy efficient and easy to apply. ZnO film is mechanically durable and resistant to chemical dissolution. Various physical tests were conducted to characterize the film. ZnO thin film exhibits the crystal wurtzite structure with band gap calculated as 3.24 eV. The film exhibits highly hydrophilic behavior. The average ZnO crystallite size is estimated as 72 nm. SEM analysis shows that the ZnO film has granular morphology with uniform particle size of about 300-400 nm. The film thickness is calculated as 1.41 mu m after 20 coating cycles and the increase of the thickness of the thin film per cycle was approximately 70 nm. Photochemical activity tests were performed by measuring photo decolorization rate of a commercial azo dye (Rem Red F3B) solution in tubular reactor and as well as in slurry reactor for comparative purpose. First order rate constants were correlated to principal process parameters. The results showed that thin ZnO film has high photocatalytic activity comparable to that of ZnO powder. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
BibTeX:
@article{Akyol2010a,
  author = {Akyol, A. and Bayramoglu, M.},
  title = {Photocatalytic performance of ZnO coated tubular reactor},
  journal = {Journal of Hazardous Materials},
  year = {2010},
  volume = {180},
  number = {1-3},
  pages = {466--473},
  url = {://WOS:000279459600059},
  doi = {10.1016/j.jhazmat.2010.04.053}
}
Akyol A and Bayramoglu M (2010), "Performance comparison of ZnO photocatalyst in various reactor systems", Journal of Chemical Technology and Biotechnology. Vol. 85(11), pp. 1455-1462.
Abstract: BACKGROUND: Owing to difficulties in catalyst recovery from slurries the deposition of a catalyst on suitable supports has been investigated extensively in recent years. The support material and the method of coating influence the activity. Photocatalytic decolorization of methyl orange (MO) and Rem Red F3B (RRF3B) was conducted in various reactor systems including a slurry reactor, ZnO thin film coated tube reactor and fixed bed reactor filled with ZnO coated ceramic or glass supports of various geometries. RESULTS: ZnO coating was carried out by the ammonium zincate deposition method. ZnO thin films were quite stable in acidic and basic media and resistant to photocorrosion. Various methods including scanning electron microscopy (SEM) and X-ray diffraction (XRD) were applied for the physical characterization of thin films. The XRD patterns of ZnO thin film exhibit a wurtzite (zincite) crystal structure. SEM analysis revealed the granular morphology of ZnO film with a particle size of 300-400 nm. CONCLUSION: Photocatalytic activities were determined kinetically by calculating first-order rate constants, which were also related to process variables by regression analysis. From the viewpoint of decolorization efficiency, the coated tube reactor (6 mm i.d.) showed the highest activity, which was equal to that of a powder catalyst loading of 300 mg dm(-3) for MO and of 200 mg dm(-3) for RRF3B. (C) 2010 Society of Chemical Industry
BibTeX:
@article{Akyol2010b,
  author = {Akyol, A. and Bayramoglu, M.},
  title = {Performance comparison of ZnO photocatalyst in various reactor systems},
  journal = {Journal of Chemical Technology and Biotechnology},
  year = {2010},
  volume = {85},
  number = {11},
  pages = {1455--1462},
  url = {://WOS:000283631600004},
  doi = {10.1002/jctb.2449}
}
Arslan-Alaton I, Gursoy BH, Akyol A, Kobya M and Bayramoglu M (2010), "Modeling and optimization of acid dye manufacturing wastewater treatment with Fenton's reagent: comparison with electrocoagulation treatment results and effects on activated sludge inhibition", Water Science and Technology. Vol. 62(1), pp. 209-216.
Abstract: In the present study, Fenton's oxidation of a chromium complex disazo dye (Acid Blue 193) synthesis wastewater was evaluated, modeled and optimized by employing Central Composite Design. Within this context, the individual and interactive effects of critical process parameters such as Fe(2+), H(2)O(2) concentrations, initial chemical oxygen demand (COD) and reaction time was assessed. The process response (output) variables were chosen as percent color, COD and total organic carbon (TOC) removal efficiencies. Optimum working conditions in terms of color and organic carbon removals were established to be Fe(2+) = 3 mM; H(2)O(2) = 25 mM; reaction time 10 min at pH 3 and an initial COD content of 245 mg/L. Under these conditions, 96% color, 82% COD and 51% TOC removals were obtained. The established polynomial regression models describing color, COD and TOC removals satisfactorily fitted the experimental data and could be used to predict Fenton's treatment results at statistically significant rates. Optimized treatment results were compared with those obtained via electrocoagulation treatment under optimized conditions (applied current = 50 A/m(2); reaction time = 15 min; initial pH = 7 for an initial COD content of 245 mg/L). The relative inhibition of heterotrophic oxygen uptake rate was measured to examine the inhibitory effect of azo dye synthesis effluent before and after Fenton's oxidation and electrocoagulation with respect to synthetic domestic wastewater. Untreated azo dye production wastewater exhibited a slightly inhibitory effect that was appreciably reduced but not entirely removed after Fenton's oxidation, whereas no inhibition of mixed bioculture was observed for azo dye synthesis effluent subjected to electrocoagulation treatment.
BibTeX:
@article{Arslan-Alaton2010,
  author = {Arslan-Alaton, I. and Gursoy, B. H. and Akyol, A. and Kobya, M. and Bayramoglu, M.},
  title = {Modeling and optimization of acid dye manufacturing wastewater treatment with Fenton's reagent: comparison with electrocoagulation treatment results and effects on activated sludge inhibition},
  journal = {Water Science and Technology},
  year = {2010},
  volume = {62},
  number = {1},
  pages = {209--216},
  url = {://WOS:000279810700028},
  doi = {10.2166/wst.2010.256}
}
Aydiner C (2010), "A novel approach based on distinction of actual and pseudo resistances in membrane fouling: "Pseudo resistance" concept and its implementation in nanofiltration of single solutions", Journal of Membrane Science. Vol. 361(1-2), pp. 96-112.
Abstract: This study proposes an integrated modeling approach based on distinction of actual and pseudo resistances to elucidate the relationships between flux decline and actual fouling in nanoscale membrane processes. The approach was based mainly upon joint solution of gel-modified concentration polarization and gel-concentration polarization-modified osmotic pressure models proposed herein. Both models were developed by a novel mass transport model in accordance with simultaneous transport of mass along sequential layers comprising concentration polarization, gel and membrane. Actual resistances of the fouling in each layer and the membrane itself could be estimated by taking into account viscosity differences of bulk solution and pure water in the pores compared to the feed solution. The implementation of the approach was carried out for nanofiltration of single solutions containing anionic dye (tartrazine), monovalent salt (NaCl) and anionic surfactant (linear alkyl benzene sulfonate, LABS). The surface properties and layer thicknesses of the membranes studied were investigated by scanning electron microscope, atomic force microscope and contact angle measurements. It was determined that flux decline increased with increasing of gel thickness regardless of solution type as directly dependent on the decrease in solvent amount penetrating from membrane-gel interface toward the membrane. External fouling accounted for the most of all actual membrane fouling with a ratio between 90.0 and 97.7% in which the gel resistance performed dominant effect with a ratio between 81.0 and 92.5%. As flux decline increased in an order of dye, NaCl and LABS, portion of actual fouling in all fouling increased by a decrease in proportional total pseudo resistance as a function of decreasing of proportional pseudo intrinsic membrane resistance. Proportional total pseudo resistances were calculated as much as 25.6, 37.3 and 60.9% for LABS, NaCl and dye solutions, respectively. These levels of total pseudo resistances put forward that the pseudo resistance approach needs to be included in mass transport domains through nanoporous membrane structures in order to eliminate both erroneous predictions of resistances in series and false interpretations of process dynamics on membrane fouling and flux decline. (C) 2010 Elsevier B.V. All rights reserved.
BibTeX:
@article{Aydiner2010,
  author = {Aydiner, C.},
  title = {A novel approach based on distinction of actual and pseudo resistances in membrane fouling: "Pseudo resistance" concept and its implementation in nanofiltration of single solutions},
  journal = {Journal of Membrane Science},
  year = {2010},
  volume = {361},
  number = {1-2},
  pages = {96--112},
  url = {://WOS:000280974600012},
  doi = {10.1016/j.memsci.2010.06.003}
}
Aydiner C, Kaya Y, Gonder ZB and Vergili I (2010), "Evaluation of membrane fouling and flux decline related with mass transport in nanofiltration of tartrazine solution", Journal of Chemical Technology and Biotechnology. Vol. 85(9), pp. 1229-1240.
Abstract: BACKGROUND: This work was carried out to investigate and analyze the interrelated dynamics of mass transport, membrane fouling and flux decline during nanofiltration of tartrazine. A combined application including pore diffusion transport model and a material balance approach was used to model an experimental flux data obtained from different values of pH (3, 5, 7 and 10), feed-dye concentration (25, 100 and 400 mg L(-1)), and transmembrane pressure (1200, 1800 and 2400 kPa). RESULTS: Almost 100% dye solution removal and a permeate flux of 135 L m(-2) h(-1) were obtained for 25 mg L(-1) and 1200 kPa at pH 10. At pH 10, lower membrane fouling was obtained due to the increase of electrostatic repulsion between anionic dye molecules and the more negatively charged membrane surface. Flux decline and membrane fouling increased together with transmembrane pressure and dye concentration. Fouling was found to be directly related to proportional-permeation coefficient (k(O)') of dye which was identified as the solute passing into the permeate with respect to the amount transported into the membrane from the feed. CONCLUSIONS: For a decrease of pH (10 to 3) and transmembrane pressure (2400 to 1200 kPa) or an increase of feed-dye concentration (25 to 400 mg L(-1)), fewer dye molecules passed into the permeate with respect to the amount transported into the membrane from the feed. This situation depended mainly on the combined influences of the gel layer and fouling in the membrane. (C) 2010 Society of Chemical Industry
BibTeX:
@article{Aydiner2010a,
  author = {Aydiner, C. and Kaya, Y. and Gonder, Z. B. and Vergili, I.},
  title = {Evaluation of membrane fouling and flux decline related with mass transport in nanofiltration of tartrazine solution},
  journal = {Journal of Chemical Technology and Biotechnology},
  year = {2010},
  volume = {85},
  number = {9},
  pages = {1229--1240},
  url = {://WOS:000281458400007},
  doi = {10.1002/jctb.2422}
}
Aydiner C, Demir I, Keskinler B and Ince O (2010), "Joint analysis of transient flux behaviors via membrane fouling in hybrid PAC/MF processes using neural network", Desalination. Vol. 250(1), pp. 188-196.
Abstract: The main purpose of this study is to understand the transient flux behaviors via membrane fouling in hybrid powdered activated carbon/microfiltration (PAC/MF) processes. Experiments were carried out for nickel solution at various surfactant adsorbent and membrane types and membrane pore sizes. Transient fluxes were modeled together using neural network (NN). A good agreement was obtained with correlation value of 0.986 and mean absolute error of 0.366 m(3)/m(2) h respectively. In hybrid processes three discriminable phase behaviors for the flux were determined as fast [0-40s] slow [40-1000s] and low stable [1000-4500s]. Considerable losses in the flux were determined during the first and the second phases while the flux reached a partial steady-state in the third phase. In the first and the third phases participation of surfactant-adsorbed PACs to the cake layer and/or interaction of surfactants and PACs in the cake with each other were found to be predominant ways for the fouling. Whereas in the second phase the interaction of surfactants with both membrane and cake layer was appeared more influential on transient flux behavior. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Aydiner2010b,
  author = {Aydiner, C. and Demir, I. and Keskinler, B. and Ince, O.},
  title = {Joint analysis of transient flux behaviors via membrane fouling in hybrid PAC/MF processes using neural network},
  journal = {Desalination},
  year = {2010},
  volume = {250},
  number = {1},
  pages = {188--196},
  url = {://WOS:000272830600029},
  doi = {10.1016/j.desal.2009.06.025}
}
Can OT and Bayramoglu M (2010), "The effect of process conditions on the treatment of benzoquinone solution by electrocoagulation", Journal of Hazardous Materials. Vol. 173(1-3), pp. 731-736.
Abstract: The present study provides an electrocoagulation (EC) process for the removal of p-benzoquinone (BQ) from aqueous solution using aluminium as anode and stainless steel as cathode materials. Experiments carried out to investigate the effects of solution pH and conductivity, current density, time, BQ concentration on the removal efficiency of the process and the adsorption capacity of aluminium hydroxide electrocoagulant flocs. The results show that pH 7.5 seems to be optimum for high removal of BQ near 90% at typical operating conditions such as 20 A/m(2) current density and 20 min operating time. The competing reduction of BQ to hydroquinone (HQ) accompanying the H(+) reduction at the cathode and low removal extent of HQ by electrocoagulant flocs decreases the performance of the EC process. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Can2010,
  author = {Can, O. T. and Bayramoglu, M.},
  title = {The effect of process conditions on the treatment of benzoquinone solution by electrocoagulation},
  journal = {Journal of Hazardous Materials},
  year = {2010},
  volume = {173},
  number = {1-3},
  pages = {731--736},
  url = {://WOS:000273135600103},
  doi = {10.1016/j.jhazmat.2009.08.146}
}
Dizge N and Tansel B (2010), "External mass transfer analysis for simultaneous removal of carbohydrate and protein by immobilized activated sludge culture in a packed bed batch bioreactor", Journal of Hazardous Materials. Vol. 184(1-3), pp. 671-677.
Abstract: External mass transfer effects were analyzed for removal of carbohydrate and protein by immobilized activated sludge culture in a packed bed bioreactor. The bioreactor was made from 52 cm glass tubing with 5.0 cm inner diameter (with a total volume of 1020 cm(3)). The microbial culture was immobilized on microporus polyurethane cut into cubic pieces of approximately 1.5 cm in length. The effect of flow rate on mass transfer and removal of carbohydrate and protein were analyzed theoretically and compared with experimental data. The rate constants were estimated using external film diffusion models at different flow rates (900, 1200, 1800 cm(3) h(-1)). Based on the experimental data, correlations between the Colburn factor (J(D)) and Reynolds number (Re) as J(D) = 5.7 x Re-.90 and J(D) = 5.7 x Re-0.18 were found to be adequate to predict the removal of carbohydrate and protein, respectively. (C) 2010 Elsevier B.V. All rights reserved.
BibTeX:
@article{Dizge2010,
  author = {Dizge, N. and Tansel, B.},
  title = {External mass transfer analysis for simultaneous removal of carbohydrate and protein by immobilized activated sludge culture in a packed bed batch bioreactor},
  journal = {Journal of Hazardous Materials},
  year = {2010},
  volume = {184},
  number = {1-3},
  pages = {671--677},
  url = {://WOS:000284504800089},
  doi = {10.1016/j.jhazmat.2010.08.090}
}
Dogan O and Karpuzcu M (2010), "Recovery of Phosphate Sludge as Concrete Supplementary Material", Clean-Soil Air Water. Vol. 38(10), pp. 977-980.
Abstract: The automotive industry plays a major role in the worldwide economy and represents an opportunity to increase the performance of the Turkish economy Phosphating units in the automotive manufacturing plants generate phosphate sludge as waste which is classified as hazardous waste in the European Waste Catalogue Phosphate sludge must be disposed of in licensed disposal plants according to the current environmental regulations Solidification/stabilization (S/S) is a widely used treatment technology for the disposal of hazardous wastes Portland cement is used for the solidification and stabilization processes to immobilize Ni and Zn in the phosphate sludge as well as to create construction material to be used as cobble stone for pavement Examination of products obtained by S/S processes is performed for two points to determine the quality and to assess the environmental impacts The phosphate sludge samples are subjected to chemical characterization and a size distribution analysis leaching test Concrete for cobble stone was produced by the S/S process with the addition of phosphate sludge to replace sand Tests for the quality of the product were carried out to determine compressive strength permeability and elasticity At the end of the leaching test elution concentrations of Zn and Ni while using water with pH values of 4 0 5 4 and 9 0 were determined to be under the limit of inert material properties Use of phosphate sludge should be considered as a sand replacement in the proportion of 1% of phosphate sludge to cement in concrete production such as for cobble stone for pavement without any adverse environmental impacts
BibTeX:
@article{Dogan2010,
  author = {Dogan, O. and Karpuzcu, M.},
  title = {Recovery of Phosphate Sludge as Concrete Supplementary Material},
  journal = {Clean-Soil Air Water},
  year = {2010},
  volume = {38},
  number = {10},
  pages = {977--980},
  url = {://WOS:000284680200010},
  doi = {10.1002/clen.201000194}
}
Etci O, Bektas N and Oncel MS (2010), "Single and binary adsorption of lead and cadmium ions from aqueous solution using the clay mineral beidellite", Environmental Earth Sciences. Vol. 61(2), pp. 231-240.
Abstract: Beidellite, a low-cost, locally available and natural mineral was used as an adsorbent for the removal of lead and cadmium ions from aqueous solutions in batch experiments. The kinetics of adsorption process was tested for the pseudo first-order, pseudo second-order reaction and intra-particle diffusion models. The rate constants of adsorption for all these kinetic models were calculated. Comparison amongst the models showed that the sorption kinetics was best described by the pseudo second-order model. Langmuir and Freundlich isotherm models were applied to the experimental equilibrium data for different temperatures. The adsorption capacities (QA degrees) of beidellite for lead and cadmium ions were calculated from the Langmuir isotherm. It was found that adsorption capacity was in the range of 83.3-86.9 for lead and 42-45.6 mg/g for cadmium at different temperatures. Thermodynamic studies showed that the metal uptake reaction by beidellite was endothermic in nature. Binary metal adsorption studies were also conducted to investigate the interactions and competitive effects in binary adsorption process. Based on the optimum parameters found, beidellite can be used as adsorbent for metal removal processes.
BibTeX:
@article{Etci2010,
  author = {Etci, O. and Bektas, N. and Oncel, M. S.},
  title = {Single and binary adsorption of lead and cadmium ions from aqueous solution using the clay mineral beidellite},
  journal = {Environmental Earth Sciences},
  year = {2010},
  volume = {61},
  number = {2},
  pages = {231--240},
  url = {://WOS:000279080600002},
  doi = {10.1007/s12665-009-0338-4}
}
Eyvaz M, Deniz H, Aktas TS, Yuksel E and Saatci AM (2010), "Pre-Ozonation-Coagulant Interactions in Direct Filtration", Water Quality Research Journal of Canada. Vol. 45(3), pp. 317-326.
Abstract: Pre-ozonation-coagulant interactions effects in relation to the coagulant type and dosage in direct filtration of surface waters were investigated. The performance of the process was evaluated by monitoring the effluent quality and head loss development through the filter bed. Two identical pilot scale filter columns filtering the same raw water were operated in parallel. The raw water was brought from Omerli Reservoir in Istanbul. Before filtering, the raw water flow was split into two equal flows. One of the streams was pre-ozonated and the other was aerated using contact chambers with equal volumes equipped with same number and type of diffusers. In coagulation experiments, one of the filters was operated using aluminum sulfate as a coagulant while the other one was run with ferric chloride. For similar filter run times, the effluent quality was always better with pre-ozonation compared to aeration. It was also observed that, aluminum sulfate application gave more favorable results for both particle and turbidity removal compared to ferric chloride. Ives' filterability index which incorporates the important filtration design parameters such as: effluent quality, the head loss and the velocity of filtration into a dimensionless number was used for the comparison of the experimental results.
BibTeX:
@article{Eyvaz2010,
  author = {Eyvaz, M. and Deniz, H. and Aktas, T. S. and Yuksel, E. and Saatci, A. M.},
  title = {Pre-Ozonation-Coagulant Interactions in Direct Filtration},
  journal = {Water Quality Research Journal of Canada},
  year = {2010},
  volume = {45},
  number = {3},
  pages = {317--326},
  url = {://WOS:000295028600005}
}
Han GSA, Bektas N and Oncel MS (2010), "Separate collection practice of packaging waste as an example of Kucukcekmece, Istanbul, Turkey", Resources Conservation and Recycling. Vol. 54(12), pp. 1317-1321.
Abstract: Turkey was required to put compatible legislation on packaging waste management in accordance with EC directives. These legal directives forced the local authorities to carry out separate collection projects for packaging waste all over the country. Packaging Waste Separate Collection Program "PWSCP" for Kucukcekmece District, Istanbul, Turkey was evaluated within the framework of the local governments' legislation in this study. The implementation of the project using the informative and educative seminars, initial collection practises and initial findings was technically and socially evaluated with respect to local awareness. This program involves separate collection of recyclable packaging materials, whereby households are requested to sort their packaging waste and local authorities are in charge for collection and follow-up. The initials results were presented using the amount and contents of packaging waste collected in the area. This new and functional project's future stages were also briefly given. A survey was conducted to analyze satisfaction and recycling level of the households. The results showed that this project was successfully implemented in the area. (C) 2010 Elsevier B.V. All rights reserved.
BibTeX:
@article{Han2010,
  author = {Han, G. S. A. and Bektas, N. and Oncel, M. S.},
  title = {Separate collection practice of packaging waste as an example of Kucukcekmece, Istanbul, Turkey},
  journal = {Resources Conservation and Recycling},
  year = {2010},
  volume = {54},
  number = {12},
  pages = {1317--1321},
  url = {://WOS:000281752400033},
  doi = {10.1016/j.resconrec.2010.05.007}
}
Ince M, Senturk E, Engin GO and Keskinler B (2010), "Further treatment of landfill leachate by nanofiltration and microfiltration-PAC hybrid process", Desalination. Vol. 255(1-3), pp. 52-60.
Abstract: Biological treatment is a commonly used process for the treatment of landfill leachate. However, with this treatment process, the permitted discharge limits cannot be consistently met, due to the recalcitrant characteristics of organic carbon in leachate. Therefore, some physico-chemical treatment technologies should be applied for the removal of inert substances, as a refining step. In this study, the main aim was to reduce the Chemical Oxygen Demand (COD) concentration of the jet-loop membrane bioreactor effluent further to meet the COD discharge limit value (700 mg COD/L) determined by the Ministry of Environment and Forestry of Turkey (MoEF). For this purpose, two different systems were used after the jet-loop membrane reactor, namely nanofiltration (NF) unit and microfiltration-powdered activated carbon (MF-PAC) hybrid system. The membranes used in the NF unit were not able to reduce the COD concentration to the desired levels. However, the MF-PAC system achieved to meet the COD discharge limit value, when 8 g PAC/L concentration was used. (C) 2010 Elsevier B.V. All rights reserved.
BibTeX:
@article{Ince2010,
  author = {Ince, M. and Senturk, E. and Engin, G. O. and Keskinler, B.},
  title = {Further treatment of landfill leachate by nanofiltration and microfiltration-PAC hybrid process},
  journal = {Desalination},
  year = {2010},
  volume = {255},
  number = {1-3},
  pages = {52--60},
  url = {://WOS:000276793600006},
  doi = {10.1016/j.desal.2010.01.017}
}
Kazanci N, Leroy SAG, Oncel S, Ileri O, Toprak O, Costa P, Sayili S, Turgut C and Kibar M (2010), "Wind control on the accumulation of heavy metals in sediment of Lake Ulubat, Anatolia, Turkey", Journal of Paleolimnology. Vol. 43(1), pp. 89-110.
Abstract: Freshwater Lake Ulubat (z (mean) = 1.5-2.0 m and Area = similar to 138 km(2)), NW Anatolia, Turkey was filled in by fine-to-medium-grain silts during the late Holocene. Deposition in Lake Ulubat has been 1.6 cm year(-1) for the last 50 years, but the sedimentation rate over the last similar to 1,600 years was lower (0.37 mm year(-1)). The organic matter and carbonate contents of the infill show cyclic changes that reflect environmental fluctuations. The silt-dominated lithology and the vertically uniform heavy metal distributions are probably due to wind-controlled sedimentation in the lake. Heterogeneous mud, derived from a large, mountainous drainage basin, is deposited in the lake mostly during summer, June to October, when conditions are hot and calm. Winter months are stormier and sediments are re-suspended due to the shallow water depth and the effect of waves on the lake bottom. It is likely that re-suspended sediments, particularly fine-grained particles, together with the heavy metals, are transported out of the lake via the outlet, especially during periods of high lake level. This resuspension and removal process probably caused the lake sediments to become silt-dominated and depleted in heavy metals. The role of broad shallow lakes in sequestering sediments and heavy metals can be described more accurately when wind data are considered. Such information may also be helpful for land-use planning in downstream areas.
BibTeX:
@article{Kazanci2010,
  author = {Kazanci, N. and Leroy, S. A. G. and Oncel, S. and Ileri, O. and Toprak, O. and Costa, P. and Sayili, S. and Turgut, C. and Kibar, M.},
  title = {Wind control on the accumulation of heavy metals in sediment of Lake Ulubat, Anatolia, Turkey},
  journal = {Journal of Paleolimnology},
  year = {2010},
  volume = {43},
  number = {1},
  pages = {89--110},
  url = {://WOS:000273162900007},
  doi = {10.1007/s10933-009-9316-9}
}
Kobya M, Demirbas E and Sozbir M (2010), "Decolorisation of aqueous reactive dye Remazol Red 3B by electrocoagulation", Coloration Technology. Vol. 126(5), pp. 282-288.
Abstract: The present study demonstrated the applicability of the electrocoagulation method for the removal of reactive dye, Remazol Red 3B, in a batch study. Iron electrode material was used as a sacrificial electrode in monopolar parallel mode in this study. The effects of the initial pH, current density, conductivity, initial concentration of dye and electrolysis time on the removal of Remazol Red 3B were investigated to determine optimum operating conditions. High decolorisation efficiency (> 99%) for Remazol Red 3B dye solution was obtained with optimal value of process parameters, such as 15 mA cm-2 of current density, 10 min of electrolysis time, pH 6 and 500 mg l-1 dye concentration. The energy consumption, electrode consumption and operating costs under optimum operating conditions were calculated as 3.3 kW h kg dye-1, 1.2 kg Fe kg dye-1 and 0.6 euro m-3, respectively.
BibTeX:
@article{Kobya2010,
  author = {Kobya, M. and Demirbas, E. and Sozbir, M.},
  title = {Decolorisation of aqueous reactive dye Remazol Red 3B by electrocoagulation},
  journal = {Coloration Technology},
  year = {2010},
  volume = {126},
  number = {5},
  pages = {282--288},
  url = {://WOS:000281849800006},
  doi = {10.1111/j.1478-4408.2010.00259.x}
}
Kobya M, Demirbas E, Parlak NU and Yigit S (2010), "Treatment of cadmium and nickel electroplating rinse water by electrocoagulation", Environmental Technology. Vol. 31(13), pp. 1471-1481.
Abstract: Treatments of cadmium-cyanide and nickel-cyanide electroplating rinse water were investigated in an electrochemical reactor equipped with iron plate electrodes in a batch mode by electrocoagulation (EC). Effects of the process variables such as pH, current density, and operating time were explored with respect to removal efficiencies of cadmium, nickel and cyanide in electroplating rinse water and operating costs as well. Removal efficiencies and operating costs under the optimum conditions (30 A/m2, 30 min and pH 8-10 for cadmium; 60 A/m2, 80 min and pH 8-10 for nickel) for the EC process in electroplating rinse water were determined as 99.4% and 1.05 /m3 for cadmium, 99.1% and 2.45 /m3 for nickel and 99.7% for cyanide, respectively. The results indicated that EC was very effective treatment for the removals of cadmium, nickel, and cyanide ions from the electroplating rinse water.
BibTeX:
@article{Kobya2010a,
  author = {Kobya, M. and Demirbas, E. and Parlak, N. U. and Yigit, S.},
  title = {Treatment of cadmium and nickel electroplating rinse water by electrocoagulation},
  journal = {Environmental Technology},
  year = {2010},
  volume = {31},
  number = {13},
  pages = {1471--1481},
  url = {://WOS:000283872000008},
  doi = {10.1080/09593331003713693}
}
Kobya M, Demirbas E, Dedeli A and Sensoy MT (2010), "Treatment of rinse water from zinc phosphate coating by batch and continuous electrocoagulation processes", Journal of Hazardous Materials. Vol. 173(1-3), pp. 326-334.
Abstract: Treatment of spent final rinse water of zinc phosphating from an automotive assembly plant was investigated in an electrochemical cell equipped with aluminum or iron plate electrodes in a batch mode by electrocoagulation (EC). Effects of the process variables such as pH, current density, electrode material and operating time were explored with respect to phosphate and zinc removal efficiencies, electrical energy and electrode consumptions. The optimum operating conditions for removal of phosphate and zinc were current density of 60.0A/m(2), pH 5.0 and operating time of 25.0 min with Al electrode and current density of 60.0A/m(2), pH 3.0 and operating time of 15.0 min with Fe electrode, respectively. The highest phosphate and zinc removal efficiencies at optimum conditions were 97.7% and 97.8% for Fe electrode, and 99.8% and 96.7% for Al electrode. The electrode consumptions increased from 0.01 to 0.35 kg electrode/m(3) for Al electrode and from 0.20 to 0.62 kg electrode/m(3) for Fe electrode with increasing current density from 10.0 to 100.0 A/m(2). The energy consumptions were 0.18-11.29 kWh/m(3) for Al electrode and 0.24-8.47 kWh/m(3) for Fe electrode in the same current density range. Removal efficiencies of phosphate and zinc were found to decrease when flow rate was increased from 50 to 400mL/min in continuous mode of operation. The morphology and elements present in the sludge was also characterized by using SEM and EDX. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kobya2010b,
  author = {Kobya, M. and Demirbas, E. and Dedeli, A. and Sensoy, M. T.},
  title = {Treatment of rinse water from zinc phosphate coating by batch and continuous electrocoagulation processes},
  journal = {Journal of Hazardous Materials},
  year = {2010},
  volume = {173},
  number = {1-3},
  pages = {326--334},
  url = {://WOS:000273135600045},
  doi = {10.1016/j.jhazmat.2009.08.092}
}
Meric E, Avsar N, Nazik A, Barut IF, Bergin F, Balkis N, Oncel MS and Kapan-Yesilyurt S (2010), "The response of benthic foraminifer, ostracod and mollusc assemblages to environmental conditions: a case study from the Camalti Saltpan (Izmir-Western Turkey)", Mediterranean Marine Science. Vol. 11(1), pp. 5-32.
Abstract: The subject of this report is benthic foraminifer populations preserved in the saltpan of Camalti in the Province of Izmir. High salinity in certain habitats of Ammonia tepida Cushman may be the primary cause of the high rate of twins and triplets as well as other morphological abnormalities recorded within this species (50 % as compared to an anomaly rate of 1 % in normal marine waters). Thicker cyst membrane developing in extremely saline environments may encourage twins and other morphological deformities by denying free movement of the offspring. Ecological factors such as heavy metal contamination of ambient waters as well as contamination by other wastes are also not ruled out as leading to such developmental anomalies. Of the 27 collected samples, Number 5 (that is closest to the sea) includes the typical marine foraminifers. Nonion depressulum (Walker and Jacob), Ammonia tepida Cushman and Porosononion subgronosum (Egger) are the dominant species in other samples. A total of 63 abnormal individuals (8 triplets, 24 twins, and 31 morphological anomalies) was found within seven of the 27 samples collected. Ten samples contained freshwater ostracods: Darwinula stevensoni (Brady and Robertson), Leptocythere lacertosa Hirschmann, Cyprideis torosa (Jones), Cyprideis (C.) anatolica Bassiouni, and Laxochoncha elliptica Brady. Among these samples (some of which contained only a few species of ostracods and those limited in number of offspring), one had an unusually high ratio of healthy foraminifers those with anomalies. Worthy of note in another sample was a high abundance of molluscs. Among pelecypods, were found ()sum edulis Linne, Lucinella divaricata (Linne), Pseudocama gryphina Lamarck, Cerastoderma Mule (Untie), and Scrobicularia plana da Costa; and among gastropods were identified Hydrobia (Hydrobia) acuta (Draparnaud), Rissoa labiosa (Montagu), R. parva (da Costa), R. violacea Desmarest. Pirenella conica (Blainville). Bittium desayesi (Cerulli and Irelli), B. lactewn Philippi and B. reficulatum Philippi.
BibTeX:
@article{Meric2010,
  author = {Meric, E. and Avsar, N. and Nazik, A. and Barut, I. F. and Bergin, F. and Balkis, N. and Oncel, M. S. and Kapan-Yesilyurt, S.},
  title = {The response of benthic foraminifer, ostracod and mollusc assemblages to environmental conditions: a case study from the Camalti Saltpan (Izmir-Western Turkey)},
  journal = {Mediterranean Marine Science},
  year = {2010},
  volume = {11},
  number = {1},
  pages = {5--32},
  url = {://WOS:000280222900001}
}
Ozoner SK, Yalvac M and Erhan E (2010), "Flow injection determination of catechol based on polypyrrole-carbon nanotube-tyrosinase biocomposite detector", Current Applied Physics. Vol. 10(1), pp. 323-328.
Abstract: A flow injection catechol biosensor based on tyrosinase entrapped in carbon nanotube modified polypyrrole biocomposite film on a glassy carbon surface has been developed. Amperometric response was measured as a function of concentration of catechol, at a fixed bias voltage of -50 mV at a flow rate of 1 mL/min. The proposed biosensor exhibited impressive analytical performance such as a linear range between 3 and 50 mu M, a short response time (10 s), a detection limit of 0.671 mu M and an excellent operational (with a relative standard deviation of 0.54%) and long-term stability (85% remained after 10th week). A comparison of the analytical parameters of the developed biosensor with polypyrrole/tyrosinase film electrode was performed in the study. CNT was shown to enhance the electron transfer between the electrode and enzyme and capable to carry higher bioactivity owing to its intensified surface area. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Ozoner2010,
  author = {Ozoner, S. K. and Yalvac, M. and Erhan, E.},
  title = {Flow injection determination of catechol based on polypyrrole-carbon nanotube-tyrosinase biocomposite detector},
  journal = {Current Applied Physics},
  year = {2010},
  volume = {10},
  number = {1},
  pages = {323--328},
  url = {://WOS:000270584900061},
  doi = {10.1016/j.cap.2009.06.017}
}
Ozoner SK, Erhan E, Yilmaz F, Celik A and Keskinler B (2010), "Newly synthesized poly(glycidyl methacrylate-co-3-thienylmethylmethacrylate)-based electrode designs for phenol biosensors", Talanta. Vol. 81(1-2), pp. 82-87.
Abstract: A newly synthesized poly(glycidyl methacrylate-co-3-thienylmethylmethacrylate) [poly(GMA-co-MTM)] was designed to fabricate various HRP electrodes for detection of phenol derivatives. The results showed that the poly(GMA-co-MTM)/polypyrrole composite film microarchitecture provided a good electroactivity as a result of pyrrole and thiophene interaction, and provided chemical bonds for enzyme immobilization via the epoxy groups of poly(GMA-co-MTM). The glassy carbon-based working electrode displayed significantly higher performance for the same composite film configuration comparing to the gold-based working electrode. Poly(GMA-co-MTM)/polypyrrole/HRP coated glassy carbon electrode exhibited a fast response less than 3s, a high sensitivity (200 nA mu M for hydroquinone), a good operational stability (%RSD values ranged between 2 and 5.1 for all phenolics). a long-term stability (retained about 80% of initial activity at the end of 40th day) and a low detection limit ranging between 0.13 and 1.87 mu M for the tested. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Ozoner2010a,
  author = {Ozoner, S. K. and Erhan, E. and Yilmaz, F. and Celik, A. and Keskinler, B.},
  title = {Newly synthesized poly(glycidyl methacrylate-co-3-thienylmethylmethacrylate)-based electrode designs for phenol biosensors},
  journal = {Talanta},
  year = {2010},
  volume = {81},
  number = {1-2},
  pages = {82--87},
  url = {://WOS:000276052700014},
  doi = {10.1016/j.talanta.2009.11.040}
}
Say ANO, Sivri N, Erturk A, Seker DZ and Li FS (2010), "ANALYSIS OF PHYTOPLANKTON DISTRIBUTION AT THE SOUTH-WESTERN COAST OF ISTANBUL UTILIZING GIS", Fresenius Environmental Bulletin. Vol. 19(9B), pp. 2116-2122.
Abstract: Marmara Sea, located between the European and Asian continents, is an important aquatic ecosystem for Turkey Together with the Bosphorus and the Dardanelles, it forms the Turkish Strait System that is an internationally important waterway From the ecological viewpoint, Marmara Sea is under high stress because of the municipal, industrial and agricultural sources of pollution as well as the intensive maritime activities, and is at risk of extensive environmental deterioration because of eutrophication The mostly populated districts of Istanbul are located at the coastal areas of the Marmara Sea In this study, chlorophyll-a and phytoplankton were monitored at the southwestern coast of Istanbul Phytoplankton species were analyzed quantitatively In general, Bacillariophyceae were found to be dominant in all the monitoring stations Cyano phyceae and Dinophyceae abundance has increased in spring Seasonal variation in phytoplankton succession was found to be related to temperature In this study, besides from bloom-forming Gymnodinium spp as Dinoflagellate members, other Dinoflagellates (Prorocentrum micans and Ceratium furca) were observed as harmful algal bloom-forming species All the results obtained by data analysis were visualized using Geographical Information System (GIS) as an initial effort to develop a local phytoplanktonic species atlas which will be important for environmental management
BibTeX:
@article{Say2010,
  author = {Say, A. N. O. and Sivri, N. and Erturk, A. and Seker, D. Z. and Li, F. S.},
  title = {ANALYSIS OF PHYTOPLANKTON DISTRIBUTION AT THE SOUTH-WESTERN COAST OF ISTANBUL UTILIZING GIS},
  journal = {Fresenius Environmental Bulletin},
  year = {2010},
  volume = {19},
  number = {9B},
  pages = {2116--2122},
  url = {://WOS:000284394100021}
}
Senturk E, Ince M and Engin GO (2010), "Treatment efficiency and VFA composition of a thermophilic anaerobic contact reactor treating food industry wastewater", Journal of Hazardous Materials. Vol. 176(1-3), pp. 843-848.
Abstract: The objective of this study was to examine the effects of organic loading rate and hydraulic retention time on volatile fatty acid composition and treatment efficiency of high rate thermophilic anaerobic contact reactor (TACR) treating potato-chips wastewaters. The operational performance of TACR was monitored from start-up by assessing chemical oxygen demand (COD) removal efficiencies, volatile fatty acid (VFA) production and biogas composition. The reactor was studied at different organic loading rates (OLRs) ranging from 0.6 to 8 kg COD/m(3) d. The COD removal efficiencies were found to be 86-97% and the methane percentage of the biogas produced was 68-89% during the OLRs studied. The approximate methane yield was found to be 0.42 m(3) CH(4)/kg COD(removed). The major intermediate products of anaerobic digestion were acetate, propionate, iso-butyrate, butyrate, iso-valerate, valerate, iso-caproate and caproate. The use of thermophilic anaerobic contact reactor offers a sustainable technology for the treatment of potato-chips wastewaters since high COD removal efficiencies and high methane percentage in the biogas produced can be attained even at high OLRs. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Senturk2010,
  author = {Senturk, E. and Ince, M. and Engin, G. O.},
  title = {Treatment efficiency and VFA composition of a thermophilic anaerobic contact reactor treating food industry wastewater},
  journal = {Journal of Hazardous Materials},
  year = {2010},
  volume = {176},
  number = {1-3},
  pages = {843--848},
  url = {://WOS:000274839700115},
  doi = {10.1016/j.jhazmat.2009.11.113}
}
Senturk E, Ince M and Engin GO (2010), "Kinetic evaluation and performance of a mesophilic anaerobic contact reactor treating medium-strength food-processing wastewater", Bioresource Technology. Vol. 101(11), pp. 3970-3977.
Abstract: High rate mesophilic anaerobic contact reactors (MACR) represent a proven sustainable technology for a wide range of different industrial effluents. These reactors demonstrate quite similar features to their aerobic counterparts, activated sludge systems. A lab-scale high rate mesophilic anaerobic contact reactor was operated with wastewater originated from a potato-processing plant, at six different loading rates of 1.1-5 g COD/L per day. The operational performance of MACR was monitored from start-up by assessing COD removal efficiency, total volatile fatty acid production and biogas composition. Furthermore, various kinetic models have been successfully applied to the experimental data to determine substrate balance, maximum utilization rate and volumetric methane production. The COD removal efficiencies were found to be 78-92% and the methane percentage of the biogas produced was 80-89%. Additionally, the methane yield coefficient was found to be 0.394 L CH(4)/gTCOD(rem). (C) 2010 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Senturk2010a,
  author = {Senturk, E. and Ince, M. and Engin, G. O.},
  title = {Kinetic evaluation and performance of a mesophilic anaerobic contact reactor treating medium-strength food-processing wastewater},
  journal = {Bioresource Technology},
  year = {2010},
  volume = {101},
  number = {11},
  pages = {3970--3977},
  url = {://WOS:000275999800025},
  doi = {10.1016/j.biortech.2010.01.034}
}
Sulak MT, Erhan E, Keskinler B, Yilmaz F and Celik A (2010), "Development of Amperometric Biosensor for Phenolic Compounds Using a Modified Electrode with Poly(GMA-co-MTM) and Laccase", Sensor Letters. Vol. 8(2), pp. 262-267.
Abstract: A new polymeric matrix, the copolymer of 3-thienylmethyl methacrylate (MTM) and glycidyl methacrylate (GMA), was used to develop a phenol biosensor based on laccase (TvLac). Chemical immobilization of the enzyme, TvLac, was achieved via the epoxy moiety of GMA onto the GMA-co-MTM coated glassy carbon electrode. GC/(GMA-co-MTM)/TvLac working electrode was investigated for the parameters of linear range, sensitivity, stability, pH and detection limit. Amperometric response was measured as a function of concentration of phenolic compounds, at a fixed bias voltage of -200 mV. The sensitivity in the linear range increased in this order with the GC/(GMA-co-MTM)/TvLac: 3-Chlorophenol > 2-Chlorophenol > 2,6-Dimethoxyphenol > Catechol > 4Methoxyphenol > 4-Chlorophenol > Phenol > Hydroquinone > 2,4-Dichlorophenol > p-Benzoquinone. The biosensor exhibited good sensitivity, stability for the tested phenolics compared to the reported working electrodes. It retained 65% of its initial activity after using for 300 measurements in one month.
BibTeX:
@article{Sulak2010,
  author = {Sulak, M. T. and Erhan, E. and Keskinler, B. and Yilmaz, F. and Celik, A.},
  title = {Development of Amperometric Biosensor for Phenolic Compounds Using a Modified Electrode with Poly(GMA-co-MTM) and Laccase},
  journal = {Sensor Letters},
  year = {2010},
  volume = {8},
  number = {2},
  pages = {262--267},
  url = {://WOS:000276808500009},
  doi = {10.1166/sl.2010.1260}
}
Sulak MT, Erhan E and Keskinler B (2010), "Amperometric Phenol Biosensor Based on Horseradish Peroxidase Entrapped PVF and PPy Composite Film Coated GC Electrode", Applied Biochemistry and Biotechnology. Vol. 160(3), pp. 856-867.
Abstract: Polyvinylferrocene (PVF) was used as a mediator for the fabrication of a horseradish peroxidase (HRP)-modified electrode to detect phenol derivatives via a composite polymeric matrix of conducting polypyrrole (PPy). Through an electropolymerization process, enzyme HRP was entrapped with PPy in a three-electrode system onto a glassy carbon electrode previously covered with PVF, resulting in a composite polymeric matrix. Steady-state amperometric measurements were performed at -200 mV vs. Ag/AgCl in aqueous phosphate buffer containing NaCl 0.1 M (pH 6.8) in the presence of hydrogen peroxide. The response of the HRP-modified PVF electrode was investigated for various phenol derivatives, which were 4-chlorophenol, phenol, catechol, hydroquinone, 2-aminophenol, pyrogallol, m-cresol, and 4-methoxyphenol. Analytical parameters for the fabricated PVF electrode were obtained from the calibration curves. The highest sensitivity was obtained from the calibration of 4-chlorophenol as 29.91 nA/mu M. The lowest detection limit was found to be 0.22 mu M (S/N = 3) for catechol, and the highest detection limit was found to be 0.79 mu M (S/N = 3) for 4-methoxyphenol among the tested derivatives. The biosensor can reach 95% of steady-state current in about 5 min. The electrode is stable for 2 months at 4 A degrees C.
BibTeX:
@article{Sulak2010a,
  author = {Sulak, M. T. and Erhan, E. and Keskinler, B.},
  title = {Amperometric Phenol Biosensor Based on Horseradish Peroxidase Entrapped PVF and PPy Composite Film Coated GC Electrode},
  journal = {Applied Biochemistry and Biotechnology},
  year = {2010},
  volume = {160},
  number = {3},
  pages = {856--867},
  url = {://WOS:000273845900018},
  doi = {10.1007/s12010-009-8534-y}
}
Arslan-Alaton I, Kobya M, Akyol A and Bayramoglu M (2009), "Electrocoagulation of azo dye production wastewater with iron electrodes: process evaluation by multi-response central composite design", Coloration Technology. Vol. 125(4), pp. 234-241.
Abstract: Central composite design was used to optimise electrocoagulation of CI Acid Blue 193 production wastewater. By applying a response surface quadratic model, the main process manipulators (effluent chemical oxygen demand, initial pH, electrical current density and treatment time) were optimised to achieve maximum colour, chemical oxygen demand and total organic compound removals. Analysis of variance indicated that the established polynomial regression models were significant and fitted the experimental data satisfactorily.
BibTeX:
@article{Arslan-Alaton2009,
  author = {Arslan-Alaton, I. and Kobya, M. and Akyol, A. and Bayramoglu, M.},
  title = {Electrocoagulation of azo dye production wastewater with iron electrodes: process evaluation by multi-response central composite design},
  journal = {Coloration Technology},
  year = {2009},
  volume = {125},
  number = {4},
  pages = {234--241},
  url = {://WOS:000269363100006},
  doi = {10.1111/j.1478-4408.2009.00202.x}
}
Aydiner C, Bayramoglu M, Keskinler B and Ince O (2009), "Nickel Removal from Waters Using a Surfactant-Enhanced Hybrid Powdered Activated Carbon/Microfiltration Process. II. The Influence of Process Variables", Industrial & Engineering Chemistry Research. Vol. 48(2), pp. 903-913.
Abstract: This study focused on the removal of nickel ions from aqueous solution using a surfactant-enhanced (SE) powdered activated carbon (PAC)/microfiltration (MF) hybrid membrane process. The main objective of the research is to investigate the technical performance of the process under the influences of all relevant process variables namely process time, recycling time, pH, temperature, PAC concentration, surfactant concentration, nickel concentration, cross-flow velocity, and transmembrane pressure, thus to reveal its applicability. to water problems involved in heavy metal pollution. The concentrations of PAC, surfactant, metal, and HI ion were determined as significant process stream variables, while transmembrane pressure and temperature came into prominence as significant operating variables. ANOVA calculations indicated that the total influences of these six variables on process performance realized in a range of about 93-98%. Nickel concentration and PAC amount in the feed were established as the most influential variables for nickel rejection, and surfactant rejection and permeate flux, respectively. The increase of PAC from 0.1 to 4 g/L led to a flux decline of about 60%. The most critical parameter for process performance was the mass ratio of PAC to surfactant (PAC/surfactant) per unit mass of metal removed. The process which may be effectively operated in continuous cross-flow filtration mode within a short filtration time of 30 min has crucial advantages compared to high pressure driven membrane processes and offers a promising alternative to remove heavy metal pollutants from drinking waters and metal bearing wastewaters.
BibTeX:
@article{Aydiner2009,
  author = {Aydiner, C. and Bayramoglu, M. and Keskinler, B. and Ince, O.},
  title = {Nickel Removal from Waters Using a Surfactant-Enhanced Hybrid Powdered Activated Carbon/Microfiltration Process. II. The Influence of Process Variables},
  journal = {Industrial & Engineering Chemistry Research},
  year = {2009},
  volume = {48},
  number = {2},
  pages = {903--913},
  url = {://WOS:000262677900043},
  doi = {10.1021/ie8004308}
}
Bahsi ZB, Buyukaksoy A, Olmezcan SM, Simsek F, Aslan MH and Oral AY (2009), "A Novel Label-Free Optical Biosensor Using Synthetic Oligonucleotides from E. coli O157:H7: Elementary Sensitivity Tests", Sensors. Vol. 9(6), pp. 4890-4900.
Abstract: SiO2-TiO2 thin films for use as fiber optic guiding layers of optical DNA biosensors were fabricated by the sol-gel dip coating technique. The chemical structure and the surface morphology of the films were characterized before immobilization. Single probe DNA strands were immobilized on the surface and the porosity of the films before the hybridization process was measured. Refractive index values of the films were measured using a Metricon 2010 prism coupler. On the surface of each film, 12 different spots were taken for measurement and calculation of the mean refractive index values with their standard deviations. The increased refractive index values after the immobilization of single DNA strands indicated that immobilization was successfully achieved. A further refractive index increase after the hybridization with target single DNA strands showed the possibility of detection of the E. coli O157:H7 EDL933 species using strands of 20-mers (5'-TAATATCGGTTGCGGAGGTG-3') sequence.
BibTeX:
@article{Bahsi2009,
  author = {Bahsi, Z. B. and Buyukaksoy, A. and Olmezcan, S. M. and Simsek, F. and Aslan, M. H. and Oral, A. Y.},
  title = {A Novel Label-Free Optical Biosensor Using Synthetic Oligonucleotides from E. coli O157:H7: Elementary Sensitivity Tests},
  journal = {Sensors},
  year = {2009},
  volume = {9},
  number = {6},
  pages = {4890--4900},
  url = {://WOS:000267339700049},
  doi = {10.3390/s90604890}
}
Basar CA, Aydiner C, Kara S and Keskinler B (2009), "Removal of Copper Ions from Waters Using Surfactant-Enhanced Hybrid PAC/MF Process", Journal of Environmental Engineering-Asce. Vol. 135(4), pp. 250-258.
Abstract: This paper deals with the removal of copper ions from aqueous solutions by using surfactant-enhanced powdered activated carbon (PAC)/microfiltration (MF) hybrid process, including the evaluation of process performance and fouling dynamics at various linear alkyl benzene sulfonate (LABS), PAC, and Cu(2+) concentrations of feed solution. Although the use of surfactant as an additive material increased the adsorption efficiency in PAC/MF hybrid process, a considerable amount of the flux was lost for surfactant concentration above critical micelle concentration. The process could be employed with a performance of 74.7%, 97.2% and 87 L/m(2) h for LABS rejection, Cu(2+) rejection and permeate flux at the conditions of 2 g PAC/L, 5 mM LABS, 0.2 mM Cu(2+), and 60-min process time. Cu(2+) rejection, which increased with increasing of LABS, and PAC amounts decreased with the increase in Cu(2+) concentration. It was understood that the increments in LABS, PAC, and Cu(2+) concentrations being an indicator for the feed solution quality led to the occurrence of more fouling on the membrane. The analyses of dynamics concerning the fouling behaviors, which were carried out using single and combined pore blocking models, put forward that the cake formation was the main predominant mechanism in the process. It was also determined that the variation of feed contents deduced the presence of rather complex fouling behaviors as a simultaneous function of secondary membrane layer formation and clogging and narrowing of membrane pores by surfactants.
BibTeX:
@article{Basar2009,
  author = {Basar, C. A. and Aydiner, C. and Kara, S. and Keskinler, B.},
  title = {Removal of Copper Ions from Waters Using Surfactant-Enhanced Hybrid PAC/MF Process},
  journal = {Journal of Environmental Engineering-Asce},
  year = {2009},
  volume = {135},
  number = {4},
  pages = {250--258},
  url = {://WOS:000264155000007},
  doi = {10.1061/(asce)0733-9372(2009)135:4(250}
}
Bayar S, Demir I and Engin GO (2009), "Modeling leaching behavior of solidified wastes using back-propagation neural networks", Ecotoxicology and Environmental Safety. Vol. 72(3), pp. 843-850.
Abstract: In a previous study, treatment sludge obtained from a chemical industry, which contained potentially toxic heavy metals and organics, was characterized and solidified by solidification/stabilization (S/S). In this study, however, the prediction of leaching behavior of the sludge by linear regression method and neural networks (NNs) was discussed. NN analysis was used to construct models of leaching behavior as a function of mix composition (waste/binder ratio, W/B) using existing data from the previous study of cement-based S/S. The differences in leaching rate of each metal were also considered. The hazard characteristics of the waste were determined as defined in both Turkish and US EPA regulations, by means of Extraction Procedure Toxicity Test (EPTox) and DIN 38414-S4 Test. S/S studies were conducted using Portland cement to solidify the sludge containing high amount of Cr, Cu, Hg, Ni, Pb, and Zn. The W/B ratios of 36 specimens were kept between 0/100 and 40/100. The specimens were cured at room temperature for 7, 28, and 90 days. The heavy metal content of the extracts of each specimen was detected usually less than standard concentrations in EPTox and DIN 38414-S4 leaching procedures. By the use of NN, leaching behavior of the solidified wastes can be predicted and, therefore, optimum S/S technologies can be achieved. (c) 2007 Elsevier Inc. All rights reserved.
BibTeX:
@article{Bayar2009,
  author = {Bayar, S. and Demir, I. and Engin, G. O.},
  title = {Modeling leaching behavior of solidified wastes using back-propagation neural networks},
  journal = {Ecotoxicology and Environmental Safety},
  year = {2009},
  volume = {72},
  number = {3},
  pages = {843--850},
  url = {://WOS:000263762100025},
  doi = {10.1016/j.ecoenv.2007.10.019}
}
Danis U and Keskinler B (2009), "Chromate removal from wastewater using micellar enhanced crossflow filtration: Effect of transmembrane pressure and crossflow velocity", Desalination. Vol. 249(3), pp. 1356-1364.
Abstract: Removal of chromate from wastewater was investigated using Micellar Enhanced Crossflow Microfiltration Technique (MEMF) with cationic surfactant, cetyltrimetylammoniumbromide (CTAB). The variation of chromate, surfactant rejections and permeate flux with time were measured at two different CTAB concentrations as a function of transmembrane pressure drop (Delta P) and crossflow velocity, while CTAB/chromate, membrane pore size, temperature and pH of the feed solution was kept constant. For low CTAB concentration, it was observed that the efficiencies of chromate and surfactant removal increased with increasing Delta P, but decreased with increasing crossflow velocities. It was also observed that the effects of crossflow velocities and Delta Ps on the rejections decreased for high CTAB concentration. It was found that fouling of the membrane by surfactant is very rapid at low crossflow velocity and high Delta Ps at low CTAB concentration. As a result of this case, both transient permeate flux (1) and steady state permeate flux (J*) decreased with decreasing crossflow velocity and increasing Delta P for both CTAB concentration. Unlike, modified fouling index (MFI) values increase with decreasing crossflow velocity and increasing Delta P. It was also observed that the effect of surfactant concentration in the 150, 200, and 250 kPa pressure and 3, 4, and 5 m/s crossflow velocity intervals dominates at high surfactant concentration. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Danis2009,
  author = {Danis, U. and Keskinler, B.},
  title = {Chromate removal from wastewater using micellar enhanced crossflow filtration: Effect of transmembrane pressure and crossflow velocity},
  journal = {Desalination},
  year = {2009},
  volume = {249},
  number = {3},
  pages = {1356--1364},
  url = {://WOS:000272438500063},
  doi = {10.1016/j.desal.2009.06.023}
}
Danis U and Aydiner C (2009), "Investigation of process performance and fouling mechanisms in micellar-enhanced ultrafiltration of nickel-contaminated waters", Journal of Hazardous Materials. Vol. 162(2-3), pp. 577-587.
Abstract: Nickel removal from aqueous solution by micellar-enhanced ultrafiltration (MEUF) with relatively low transmembrane pressures was investigated at varying conditions of sodium lauryl ether sulfate (SLES) and nickel concentrations, transmembrane pressure and sodium chloride content. Process employed in continuous filtration mode, could be operated within a short time of 30 min presenting high rejection of nickel and SLES at high transient fluxes. Under the effect of increasing transmembrane pressure, the rejection of nickel and SLES increased, but the transient flux decreased. The existence of salt caused to decrease both rejections and flux. Nickel rejection, SLES rejection and flux were establihed as 98.6%, 75.7% and 0.304 m(3)/m(2) h, respectively, for the conditions of surfactant to metal (SIM) ratio of 10 (SLES = 2 mM), transmembrane pressure of 250 kPa without NaCl content at the end of 90-min operation time. The analyses related to the membrane fouling were carried out using adsorptive fouling models. It has been determined that, the fouling occurs as a dynamic function of various process conditions studied, and depends strongly on mechanisms controlled by the formation of gel layer and its bridging over the pore entrances simultaneously together with partial constriction of membrane pores by surfactant adsorption. (C) 2008 Elsevier B.V. All rights reserved.
BibTeX:
@article{Danis2009a,
  author = {Danis, U. and Aydiner, C.},
  title = {Investigation of process performance and fouling mechanisms in micellar-enhanced ultrafiltration of nickel-contaminated waters},
  journal = {Journal of Hazardous Materials},
  year = {2009},
  volume = {162},
  number = {2-3},
  pages = {577--587},
  url = {://WOS:000263370200001},
  doi = {10.1016/j.jhazmat.2008.05.098}
}
Demirbas E, Dizge N, Sulak MT and Kobya M (2009), "Adsorption kinetics and equilibrium of copper from aqueous solutions using hazelnut shell activated carbon", Chemical Engineering Journal. Vol. 148(2-3), pp. 480-487.
Abstract: The adsorption of Cu(II) ions from aqueous solutions by hazelnut shell activated carbon (HSAC) was studied in a batch adsorption system. Factors influencing copper adsorption such as initial copper ion concentration (25-200 mg L-1), pH (2-6), adsorbent dosage (0.5-3.0 g L-1) and temperature (293-323 K) were investigated. The adsorption process was relatively fast and equilibrium was established about 90 min. Maximum adsorption of Cu(II) ions occurred at around pH 6. A comparison of the kinetic models on the overall adsorption rate showed that the adsorption system was best described by the pseudo second-order kinetics. Desorption experiments were carried out to test the performance of the carbon and desorption efficiencies in four cycles were found to be in the range 74-79%. The adsorption equilibrium data fitted best with the Langmuir isotherm and the monolayer adsorption capacity of Cu(II) ions was determined as 58.27 mg g(-1) at 323 K. Thermodynamic parameters were calculated for the Cu(II) ion-HSAC system and the positive value of OH (18.77 kJ mol(-1)) showed that the adsorption was endothermic and physical in nature. (c) 2008 Elsevier B.V. All rights reserved.
BibTeX:
@article{Demirbas2009,
  author = {Demirbas, E. and Dizge, N. and Sulak, M. T. and Kobya, M.},
  title = {Adsorption kinetics and equilibrium of copper from aqueous solutions using hazelnut shell activated carbon},
  journal = {Chemical Engineering Journal},
  year = {2009},
  volume = {148},
  number = {2-3},
  pages = {480--487},
  url = {://WOS:000264918900036},
  doi = {10.1016/j.cej.2008.09.027}
}
Dizge N, Keskinler B and Tanriseven A (2009), "Biodiesel production from canola oil by using lipase immobilized onto hydrophobic microporous styrene-divinylbenzene copolymer", Biochemical Engineering Journal. Vol. 44(2-3), pp. 220-225.
Abstract: In this study, the methyl esters of the long chain fatty acids (biodiesel) were synthesized by methanolysis of canola oil by immobilized lipase. Lipase from Thermomyces lanuginosus was immobilized by both physical adsorption and covalent attachment onto polyglutaraldehyde activated styrene-divinylbenzene (STY-DVB) copolymer, which is synthesized by using high internal phase emulsion (polyHIPE). Two different STY-DVB copolymers were evaluated: STY-DVB copolymer and STY-DVB copolymer containing polyglutaraldehyde (STY-DVB-PGA). Lipase from T lanuginosus was immobilized with 60% and 85% yield on the hydrophobic microporous STY-DVB and STY-DVB-PGA copolymer, respectively. Biodiesel production using the latter lipase preparation was realized by a three-step addition of methanol to avoid strong substrate inhibition. Under the optimized conditions, the maximum biodiesel yield was 97% at 50 degrees C in 24 h reaction. The immobilized enzyme retained its activity during the 10 repeated batch reactions. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Dizge2009,
  author = {Dizge, N. and Keskinler, B. and Tanriseven, A.},
  title = {Biodiesel production from canola oil by using lipase immobilized onto hydrophobic microporous styrene-divinylbenzene copolymer},
  journal = {Biochemical Engineering Journal},
  year = {2009},
  volume = {44},
  number = {2-3},
  pages = {220--225},
  url = {://WOS:000264903900018},
  doi = {10.1016/j.bej.2008.12.008}
}
Dizge N, Keskinler B and Barlas H (2009), "Sorption of Ni(II) ions from aqueous solution by Lewatit cation-exchange resin", Journal of Hazardous Materials. Vol. 167(1-3), pp. 915-926.
Abstract: Ion-exchange is an alternative process for uptake of heavy metals from aqueous solutions. In the present study, the sorption of nickel(II) ions from aqueous solution was investigated by using Lewatit MonoPlus SP 112 (strongly acidic, macroporous cation-exchange resin) in a batch adsorption system as a function of pH (2.0-8.0), initial nickel concentration (50-200 mg/L), resin dosage (0.5-2.0 g/L), contact time (0.5-3h), and temperatures (298-318K). The data were analyzed on the basis of Lagergren pseudo-first order, pseudo-second order (Types 1-5), Elovich and external, Weber-Morris intraparticle, pore-surface mass diffusion models. The experimental data showed that the maximum pH for efficient sorption of nickel(II) was 6.0. At the optimal conditions, nickel(II) ions sorption on the resin was decreased when the initial metal concentration increased. The results indicated that the resin dosage strongly affected the amount of nickel(H) ions removed from aqueous solution. The adsorption process was very fast due to 80% of nickel(II) sorption was occurred within 30 min and equilibrium was reached at about 90 min, Freundlich and Langmuir adsorption isotherm models were used for sorption equilibrium data and the maximum adsorption capacity (171 mg/g) of Lewatit MonoPlus SP 112 was obtained from Langmuir isotherm. The thermodynamic parameters (Delta G degrees, free energy change; Delta S degrees, enthalpy change; and Delta H degrees, entropy change) for sorption of nickel(II) ions were evaluated. The rise in temperature caused a partly increase in the value of the equilibrium constant (K-c) for the sorption of nickel(II) ions. Moreover, column flow adsorption study was also studied. Breakthrough curves were obtained from column flow studies by using both synthetic solution and rinsing bath water of filter industry. The column regeneration was carried out for two sorption-desorption cycles. The eluant used for regeneration of the cation-exchange resin was 7% (w/w) HCl. The experimental results demonstrated that Lewatit MonoPlus SP 112 cation-exchange resin could be used effectively for the removal of nickel(II) ions from aqueous medium. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Dizge2009a,
  author = {Dizge, N. and Keskinler, B. and Barlas, H.},
  title = {Sorption of Ni(II) ions from aqueous solution by Lewatit cation-exchange resin},
  journal = {Journal of Hazardous Materials},
  year = {2009},
  volume = {167},
  number = {1-3},
  pages = {915--926},
  url = {://WOS:000267267000133},
  doi = {10.1016/j.jhazmat.2009.01.073}
}
Dizge N, Demirbas E and Kobya M (2009), "Removal of thiocyanate from aqueous solutions by ion exchange", Journal of Hazardous Materials. Vol. 166(2-3), pp. 1367-1376.
Abstract: The adsorption kinetics and equilibrium of thiocyanate in aqueous solutions onto an anion-exchange resin (Purolite A-250) were investigated in a batch-mode operation to assess the possible use of this adsorbent. The effect of various parameters such as initial thiocyanate concentration, contact time, pH, particle size, resin dosage and temperature were studied. A comparison of four kinetic models, the pseudo-first-order, second-order, Elovich and diffusion controlled kinetic models, on the thiocyanate-resin system was used to determine the rate constants and the adsorption mechanism. The kinetic results correlated well with pseudo-second-order model. The experimental parameters had also an effect on the pore and surface diffusivities. The optimum conditions for removal of thiocyanate were found to be pH 8,2 g/l of adsorbent dosage, 355-500 mu m of particle size and equilibrium time of 30 min, respectively. The column capacity and performance by the bed depth service time model using bed depth and flow rate as variables were evaluated. The adsorption isotherm data were fitted well to Langmuir and Freundlich isotherms. The adsorption capacity was calculated as 191.20 mg/g at 323 K. Thermodynamics parameters such as free Delta G(0), Delta H(0) and Delta S(0) for the adsorption were evaluated. The positive value of Delta H(0) indicated that the process was endothermic in nature. (C) 2008 Elsevier B.V. All rights reserved.
BibTeX:
@article{Dizge2009b,
  author = {Dizge, N. and Demirbas, E. and Kobya, M.},
  title = {Removal of thiocyanate from aqueous solutions by ion exchange},
  journal = {Journal of Hazardous Materials},
  year = {2009},
  volume = {166},
  number = {2-3},
  pages = {1367--1376},
  url = {://WOS:000266947000114},
  doi = {10.1016/j.jhazmat.2008.12.049}
}
Dizge N, Aydiner C, Imer DY, Bayramoglu M, Tanriseven A and Keskinlera B (2009), "Biodiesel production from sunflower, soybean, and waste cooking oils by transesterification using lipase immobilized onto a novel microporous polymer", Bioresource Technology. Vol. 100(6), pp. 1983-1991.
Abstract: This study aims at carrying out lipase-catalyzed synthesis of fatty acid methyl esters (biodiesel) from various vegetable oils using lipase immobilized onto a novel microporous polymeric matrix (MPPM) as a low-cost biocatalyst. The research is focused on three aspects of the process: (a) MPPM synthesis (monolithic, bead, and powder forms), (b) microporous polymeric biocatalyst (MPPB) preparation by immobilization of lipase onto MPPM, and (c) biodiesel production by MPPB. Experimental planning of each step of the study was separately carried out in accordance with design of experiment (DoE) based on Taguchi methodology. Microporous polymeric matrix (MPPM) containing aldehyde functional group was synthesized by polyHIPE technique using styrene, divinylbenzene, and polyglutaraldehyde. Thermomyces lanuginosus lipase was covalently attached onto MPPM with 80%, 85%, and 89% immobilization efficiencies using bead, powder, and monolithic forms, respectively. Immobilized enzymes were successfully used for the production of biodiesel using sunflower, soybean, and waste cooking oils. It was shown that immobilized enzymes retain their activities during 10 repeated batch reactions at 25 degrees C, each lasting 24 h. Since the developed novel method is simple yet effective, it could have a potential to be used industrially for the production of chemicals requiring immobilized lipases. (c) 2008 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Dizge2009c,
  author = {Dizge, N. and Aydiner, C. and Imer, D. Y. and Bayramoglu, M. and Tanriseven, A. and Keskinlera, B.},
  title = {Biodiesel production from sunflower, soybean, and waste cooking oils by transesterification using lipase immobilized onto a novel microporous polymer},
  journal = {Bioresource Technology},
  year = {2009},
  volume = {100},
  number = {6},
  pages = {1983--1991},
  url = {://WOS:000262750000015},
  doi = {10.1016/j.biortech.2008.10.008}
}
Ergenekon P, Ozturk NK and Tavsan S (2009), "ENVIRONMENTAL AIR LEVELS OF VOLATILE ORGANIC COMPOUNDS BY THERMAL DESORPTION-GAS CHROMATOGRAPHY IN AN INDUSTRIAL REGION", Fresenius Environmental Bulletin. Vol. 18(11), pp. 1999-2003.
Abstract: Benzene, Toluene, Ethylbenzene and Xylene (BTEX) are the group of VOCs widely used as representative of VOC pollution. In this study BTEX measurements were made in Dilovasi at two selected points. One was at the center of the town (DLV) and the other was GYTE campus which can be considered as a background area. Dilovasi is a coastal town in the Marmara region known for its deteriorated environmental conditions. Cancer is the primary death cause for Dilovasi residents with a ratio three times higher than Turkey's general average. Active and passive tube sampling methods were used to collect the air samples and BTEX levels were determined by thermal desorption GC-FID analytical system. In the preparatory step long term passive sampling results for 2, 3, and 4 weeks sampling times were compared and 2-week sampling was chosen due to observed lowest back diffusion. BTEX concentration ratios were calculated as (5.4; 9.1;1.03.1) at DLV and (6.1;7.5;1.0;2.2) at GYTE using passive sampling results. Active samples taken in the morning at DLV showed significant correlation among BTEX compounds suggesting the effect of traffic related VOC pollution at the site while GYTE is not under direct effect of VOC sources but having polluted aged air masses. BTEX levels from active tube sampling exhibit up to 5 times of the concentration values obtained from passive sampling
BibTeX:
@article{Ergenekon2009,
  author = {Ergenekon, P. and Ozturk, N. K. and Tavsan, S.},
  title = {ENVIRONMENTAL AIR LEVELS OF VOLATILE ORGANIC COMPOUNDS BY THERMAL DESORPTION-GAS CHROMATOGRAPHY IN AN INDUSTRIAL REGION},
  journal = {Fresenius Environmental Bulletin},
  year = {2009},
  volume = {18},
  number = {11},
  pages = {1999--2003},
  url = {://WOS:000272582500002}
}
Eyvaz M, Kirlaroglu M, Aktas TS and Yuksel E (2009), "The effects of alternating current electrocoagulation on dye removal from aqueous solutions", Chemical Engineering Journal. Vol. 153(1-3), pp. 16-22.
Abstract: The main goal of this Study is to investigate the effects of alternating current (AC) on dye removal from aqueous solutions by electrocoagulation (EC). An EC system with parallel-connected aluminium electrodes was operated in batch mode. Two different aqueous dye Solutions were used: one was obtained from Dianix Yellow CC (DY) and the other was obtained using Procion Yellow (PY). The experiments employing direct current (DC) were carried Out using a DC power supply. The AC experiments were conducted using rectangular wave, which is produced with an adjustable time relay connected to the Output of DC power Supply. This current is called alternating pulse Current (APC) in order to refer AC system in this Study. Total organic carbon (TOC) and dye removal efficiencies were measured to assess treatment efficiency. Operating cost was calculated for both power Supply systems and alternating pulse Current was found Superior to direct current for the treatment of reactive and disperse dyes used in this study. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Eyvaz2009,
  author = {Eyvaz, M. and Kirlaroglu, M. and Aktas, T. S. and Yuksel, E.},
  title = {The effects of alternating current electrocoagulation on dye removal from aqueous solutions},
  journal = {Chemical Engineering Journal},
  year = {2009},
  volume = {153},
  number = {1-3},
  pages = {16--22},
  url = {://WOS:000274348600003},
  doi = {10.1016/j.cej.2009.05.028}
}
Kara S, Keskinler B and Erhan E (2009), "A novel microbial BOD biosensor developed by the immobilization of P. Syringae in micro-cellular polymers", Journal of Chemical Technology and Biotechnology. Vol. 84(4), pp. 511-518.
Abstract: BACKGROUND: A biochemical oxygen demand (BOD) sensor, based on an immobilized Pseudomonas syringae in highly porous micro-cellular polymer (MCP) in combination with a dissolved oxygen electrode, has been developed for the analysis of biodegradable organic compounds in aqueous samples. Microorganisms were immobilized in a molded MCP disk and a wastewater sample was injected into the biocomposite disk by a flow injection system. Dissolved oxygen (DO) changes as a measure of soluble BOD was read with a DO probe placed into a flow cell carrying biocatalytically activated disk. RESULTS: Optimal response of the MCP BOD sensor was obtained at pH 6.8 and 25 degrees C with a typical response time of 3-5 min for a 2 mm thick molded polymeric disk. The sensor showed detection linearity over the range 5-100 mg L-1 BOD5 (r(2) > 0.99) at a flow rate of 0.6 mL min(-1). The repeatability and reproducibility of the sensor response were found to be 3.08% and 7.77%, respectively. BOD values produced with this biosensor for various municipal and industrial wastewaters correlated well with those determined by the conventional 5-day BOD test. CONCLUSION: This new biosensor was different from present amperometric BOD biosensor configurations in which the biocatalyst (microbial/enzymatic) is placed between cellulose and Teflon membranes installed on a DO probe. The use of a molded MCP disk coniainng microbial activity offers better stability and lifetime for commercial use in environmental monitoring. (c) 2008 Society of Chemical Industry
BibTeX:
@article{Kara2009,
  author = {Kara, S. and Keskinler, B. and Erhan, E.},
  title = {A novel microbial BOD biosensor developed by the immobilization of P. Syringae in micro-cellular polymers},
  journal = {Journal of Chemical Technology and Biotechnology},
  year = {2009},
  volume = {84},
  number = {4},
  pages = {511--518},
  url = {://WOS:000264946500006},
  doi = {10.1002/jctb.2071}
}
Karagoz P, Erhan E, Keskinler B and Ozkan M (2009), "The Use of Microporous Divinyl Benzene Copolymer for Yeast Cell Immobilization and Ethanol Production in Packed-Bed Reactor", Applied Biochemistry and Biotechnology. Vol. 152(1), pp. 66-73.
Abstract: Microporous divinyl benzene copolymer (MDBP) was used for the first time as immobilization material for Saccharomyces cerevisiae ATCC 26602 cells in a bed reactor and ethanol production from glucose was studied as a model system. A very homogenous thick layer of yeast cells were seen from the scanning electron micrographs on the outer walls of biopolymer. The dried weight of the cells was found to be approximately 2 g per gram of cell supporting material. Hydrophobic nature of polymer is an important factor increasing cell adhesion on polymer pieces. The dynamic flow conditions through the biomaterial due to its microporous architecture prevented exopolysaccharide matrix formation around cells and continuous washing out of toxic metabolites and dead and degraded cells from the reactor provided less diffusional limitations and dynamic living environment to the cells. In order to see the ethanol production performance of immobilized yeast cells, a large initial concentration range of glucose between 6.7 and 300 g/l was studied at 1 ml/min in continuous packed-bed reactor. The inhibition effect of glucose with increasing initial concentration was observed at above 150 g/l, a relatively high substrate concentration. The continuous fluid flow around the microenvironment of the attached cells and mass transferring ability of cell immobilized on MDBP can help in decreasing the inhibition effect of ethanol accumulation and high substrate concentration in the vicinity of the cells.
BibTeX:
@article{Karagoz2009,
  author = {Karagoz, P. and Erhan, E. and Keskinler, B. and Ozkan, M.},
  title = {The Use of Microporous Divinyl Benzene Copolymer for Yeast Cell Immobilization and Ethanol Production in Packed-Bed Reactor},
  journal = {Applied Biochemistry and Biotechnology},
  year = {2009},
  volume = {152},
  number = {1},
  pages = {66--73},
  url = {://WOS:000262280600007},
  doi = {10.1007/s12010-008-8336-7}
}
Kobya M, Demirbas E and Akyol A (2009), "Electrochemical treatment and operating cost analysis of textile wastewater using sacrificial iron electrodes", Water Science and Technology. Vol. 60(9), pp. 2261-2270.
Abstract: Electrocoagulation (EC) method with iron electrode was used to treat the textile wastewater in a batch reactor. Iron electrode material was used as a sacrificial electrode in monopolar parallel mode in this study. The removal efficiencies of the wastewater by EC were affected by initial pH of the solution, current density, conductivity and time of electrolysis. Under the optimal experimental conditions (initial pH 6.9, current density of 10 mA/cm(2), conductivity of 3,990 mu S/cm, and electrolysis time of 10 min), the treatment of textile wastewater by the EC process led to a removal capacity of 78% of chemical oxygen demand (COD) and 92% of turbidity. The energy and electrode consumptions at the optimum conditions were calculated to be 0.7 kWh/kg COD (1.7 kWh/m(3)) and 0.2 kgFe/kg COD (0.5 kgFe/m(3)), respectively. Moreover, the operating cost was calculated as 0.2 (sic)/kg removed COD or 0.5 (sic)/m(3) treated wastewater. Zeta potential measurement was used to determine the charge of particle formed during the EC which revealed that Fe(OH) 3 might be responsible for the EC process.
BibTeX:
@article{Kobya2009,
  author = {Kobya, M. and Demirbas, E. and Akyol, A.},
  title = {Electrochemical treatment and operating cost analysis of textile wastewater using sacrificial iron electrodes},
  journal = {Water Science and Technology},
  year = {2009},
  volume = {60},
  number = {9},
  pages = {2261--2270},
  url = {://WOS:000271936500007},
  doi = {10.2166/wst.2009.672}
}
Ozkan M, Erhan E, Terzi O, Tan I and Ozoner SK (2009), "Thermostable amperometric lactate biosensor with Clostridium thermocellum L-LDH for the measurement of blood lactate", Talanta. Vol. 79(5), pp. 1412-1417.
Abstract: The gene for Clostridium thermocellum L-lactate dehydrogenase enzyme was cloned into pGEX-4T-2 purification vector to supply a source for a thermostable enzyme in order to produce a stable lactate biosensor working at relatively high temperatures. The purified thermostable enzyme (t-LDH) was then immobilized on a gold electrode via polymerization of polygluteraldehyde and pyrrol resulting in a conductive co-polymer. t-LDH working electrode (t-LDHE) was used for determination of lactate in CHES buffer. Amperometric response of the produced electrodes was measured as a function of lactate concentration, at a fixed bias voltage of 200mV in a three-electrode system. The linear range and sensitivity of the biosensor was investigated at various temperatures in the range of 25-60 degrees C. The sensitivity t-LDHE increased with increasing the temperature and reached its highest value at 60 degrees C. The calculated value was nearly 70 times higher as compared to the sensitivity value of the same electrode tested at 25 degrees C. The sensing parameters of t-LDHE were compared with the electrodes produced by commercially available rabbit muscle LDH (m-LDH). The sensitivity of t-LDHE was nearly 8 times higher than that of m-LDHE. t-LDHE was found to retain its activity for a week incubation at refrigerator (+5 degrees C), while m-LDHE lost its activity in this period. t-LDHE was also tested in the presence of human blood serum. The results showed that the current increased with increasing concentrations of lactate in the human blood serum and the biosensor is more sensitive to serum lactate as well as the commercial lactate dissolved in serum as compared to the commercial lactate dissolved in CHES buffer. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Ozkan2009,
  author = {Ozkan, M. and Erhan, E. and Terzi, O. and Tan, I. and Ozoner, S. K.},
  title = {Thermostable amperometric lactate biosensor with Clostridium thermocellum L-LDH for the measurement of blood lactate},
  journal = {Talanta},
  year = {2009},
  volume = {79},
  number = {5},
  pages = {1412--1417},
  url = {://WOS:000269288400034},
  doi = {10.1016/j.talanta.2009.06.012}
}
Ozoner SK, Can MY, Keskinler B and Erhan E (2009), "A Novel Poly(Glutaraldehyde-co-Pyrrole)/Horseradish Peroxidase Composite Film Electrode", Analytical Letters. Vol. 42(18), pp. 3058-3072.
Abstract: A newly synthesized copolymer, Poly(glutaraldehyde-co-pyrrole) was used to immobilize horseradish peroxidase for the construction of an amperometric biosensor for detection of phenols in a flow injection system. Infrared spectra of Poly(glutaraldehyde-co-pyrrole) showed that the incorporation of aldehyde groups into the conductive polymeric backbone was achieved. The [image omitted] values were found to be in the range of 0.077-0.468mM for p-benzoquinone and 0.112-0.709mM for catechol, at various flow rates ranging between 0.25-6mL/min. The sensitivities at various flow rates ranged between 100-200nA/mM for catechol and 30-100nA/mM for p-benzoquinone. The biosensor retained its initial activity for 1 month.
BibTeX:
@article{Ozoner2009,
  author = {Ozoner, S. K. and Can, M. Y. and Keskinler, B. and Erhan, E.},
  title = {A Novel Poly(Glutaraldehyde-co-Pyrrole)/Horseradish Peroxidase Composite Film Electrode},
  journal = {Analytical Letters},
  year = {2009},
  volume = {42},
  number = {18},
  pages = {3058--3072},
  url = {://WOS:000271812000010},
  doi = {10.1080/00032710903276489}
}
Ozturk ZZ, Tasaltin C, Engin GO, Gurek AG, Atilla D, Ahsen V and Ince M (2009), "Evaluation of a fast wastewater odour characterisation procedure using a chemical sensor array", Environmental Monitoring and Assessment. Vol. 151(1-4), pp. 369-375.
Abstract: Sewage treatment works are one of the major sources that cause atmospheric odour pollution. The increase in the number of complaints about odour nuisance is due to the increase in environmental concerns. Unfortunately, the legislation on odour nuisance from sewage treatment works is very limited. In order to determine suitable thresholds on which to base legal standards, reliable and efficient odour measurement methods need to be defined. A chemical sensor array was developed for the purpose of measuring wastewater odour. This paper describes the development of the chemical sensor system which is specifically tuned to odours of wastewater origin and which can give an electronic measure of the wastewater odours. Odour emissions from a wastewater treatment facility were detected by using a quartz crystal microbalance (QCM) sensor array. The array consists of nine sensor elements, which were coated with different materials. In this paper, the usage of these novel instruments in the water industry was shown.
BibTeX:
@article{Ozturk2009,
  author = {Ozturk, Z. Z. and Tasaltin, C. and Engin, G. O. and Gurek, A. G. and Atilla, D. and Ahsen, V. and Ince, M.},
  title = {Evaluation of a fast wastewater odour characterisation procedure using a chemical sensor array},
  journal = {Environmental Monitoring and Assessment},
  year = {2009},
  volume = {151},
  number = {1-4},
  pages = {369--375},
  url = {://WOS:000263832800035},
  doi = {10.1007/s10661-008-0278-6}
}
Sunlu FS, Demir I, Engin GO, Buyukisik B, Sunlu U, Koray T and Kukrer S (2009), "Nanoplankton population dynamics and dissolved oxygen change across the bay of Izmir by neural networks", Journal of Environmental Monitoring. Vol. 11(6), pp. 1165-1168.
Abstract: The bay of Izmir, which is the biggest harbor on the Aegean Sea, is of upmost economical importance for Izmir, the third largest city in Turkey. Most of the studies carried out focused on the effects of intensive industrial activity and agricultural production on the bay pollution within the region. These studies, most of the time, are limited to monitoring the level of pollution. However, it is believed that these studies should be supported with models and statistical analysis techniques, as the models, especially the prediction ones, provide an important approach to assessing risk and assessment. In this study, neural network analysis was used to construct prediction models for nanoplankton population change with nutrients and other environmentally important parameters. The results indicated that, using data over a 52 week period, it is possible to predict nanoplankton population dynamics and dissolved oxygen change for the future.
BibTeX:
@article{Sunlu2009,
  author = {Sunlu, F. S. and Demir, I. and Engin, G. O. and Buyukisik, B. and Sunlu, U. and Koray, T. and Kukrer, S.},
  title = {Nanoplankton population dynamics and dissolved oxygen change across the bay of Izmir by neural networks},
  journal = {Journal of Environmental Monitoring},
  year = {2009},
  volume = {11},
  number = {6},
  pages = {1165--1168},
  url = {://WOS:000266795900005},
  doi = {10.1039/b815185g}
}
Tekbas M, Bektas N and Yatmaz HC (2009), "Adsorption studies of aqueous basic dye solutions using sepiolite", Desalination. Vol. 249(1), pp. 205-211.
Abstract: Sepiolite, low cost, locally available and natural mineral was studied as an adsorbent for the removal of Basic Astrazon yellow 7GL from aqueous solutions and batch contact tests. The kinetics of the adsorption process was tested for the pseudo-first order, pseudo-second order reaction and intra-particle diffusion models. The rate constants of adsorption for all these kinetic models were calculated. Good correlation coefficients were obtained for the pseudo-second order kinetic model. Langmuir, Freundlich and Dubinin-Radushkevich isotherm models were applied to the experimental equilibrium data by changing temperature. The isotherm constants were determined by using the linear regression of these models. The monolayer coverage capacities of sepiolite for basic dye were found to be in the range of 62.5-88.5 mg/g at different temperatures. Thermodynamic studies showed that the reaction for dye uptake by sepiolite is endothermic in nature. Based on the optimum parameters sepiolite was also used as adsorbent for raw wastewater treatment and found as efficient as dye color removal. (C) 2009 Elsevier B.V. All rights reserved.
BibTeX:
@article{Tekbas2009,
  author = {Tekbas, M. and Bektas, N. and Yatmaz, H. C.},
  title = {Adsorption studies of aqueous basic dye solutions using sepiolite},
  journal = {Desalination},
  year = {2009},
  volume = {249},
  number = {1},
  pages = {205--211},
  url = {://WOS:000271955400033},
  doi = {10.1016/j.desal.2008.10.028}
}
Uyar G, Avcil E, Oren M, Karaca F and Oncel MS (2009), "Determination of Heavy Metal Pollution in Zonguldak (Turkey) by Moss Analysis (Hypnum cupressiforme)", Environmental Engineering Science. Vol. 26(1), pp. 183-194.
Abstract: This paper explores the first attempt at determining the levels of atmospheric heavy metal contamination in the Zonguldak province through the analysis of moss (Hypnum cupressiforme Hedw.). Sampling was performed at 24 sites after a wet period to avoid contamination from soil compounds in the province. Dried samples, which were unwashed but cleaned of soil particles and other extraneous material, were digested with HNO(3)/HClO(4). Concentrations of heavy metals (Fe, Cu, Pb, Cr, Co, Ni, and As) were analyzed by ICP-OES to estimate the geographic distribution of the atmospheric heavy metal depositions. The general order of the concentrations of the heavy metal content in Hypnum cupressiforme Hedw. was observed to be Fe > Pb > Cu > Ni > Cr > As > Co. Mean levels of the measured elements were higher when compared to European levels. Arsenic, iron, and chromium were the most elevated elements when compared with European data. The mean concentrations of these elements in the studied area were 8.3 (Co), 6.7 (Fe), 5.2 (Cr), 4.6 (As), and 2.7 (Ni) times the background levels of the reference site (C3). Among the studied heavy metals, only lead showed little variation in measured values due to traffic in the area. Main sources of increased heavy metal content of the moss samples were found to be: i) the Catalagzi Power Plant (CATES); ii) the Eregli Iron-Steel Plant (ERDEMIR); iii) space heating; and iv) traffic-related emissions. Results are presented in the form of color-scaled contour maps using a Geographic Information System (GIS)-based mapping technique.
BibTeX:
@article{Uyar2009,
  author = {Uyar, G. and Avcil, E. and Oren, M. and Karaca, F. and Oncel, M. S.},
  title = {Determination of Heavy Metal Pollution in Zonguldak (Turkey) by Moss Analysis (Hypnum cupressiforme)},
  journal = {Environmental Engineering Science},
  year = {2009},
  volume = {26},
  number = {1},
  pages = {183--194},
  url = {://WOS:000262495900020},
  doi = {10.1089/ees.2007.0253}
}
Yatmaz HC and Uzman Y (2009), "Degradation of Pesticide Monochrotophos from Aqueous Solutions by Electrochemical Methods", International Journal of Electrochemical Science. Vol. 4(5), pp. 614-626.
Abstract: The degradation of toxic monochrotophos (MCP) was comparatively studied by electrochemical methods such as direct electrooxidation, indirect electrooxidation, electrocoagulation and electro-Fenton processes. In the direct electrooxidation process using Ti electrodes in electrolyte solutions (6 g/L of NaCl) at two different current densities of 50 and 100 A/m(2), degradation of MCP from aqueous solutions in different initial concentrations (50, 100, 200, 300 mg/L) was investigated to evaluate MCP degradation. It was determined that increases in the initial MCP concentration and current density lead to increase MCP degradation. In this process, considering the effects of different electrolyte concentrations of NaCl (1, 3, 6 g/L) and different electrolyte (6 g/L Na(2)SO(4)), it was observed that high NaCl concentration increases the MCP degradation and decreases the energy consumption. The degradation and removal of 300 mg/L MCP solution by electrocoagulation using Fe electrodes (pH 8.5, 6 g/L NaCl, 93 A/m(2)) was investigated and 78% removal was achieved. The degradation and mineralization of 300 mg/L MCP solution (6 g/L NaCl, 50 A/m(2)) by the indirect electrooxidation processes using Ti electrodes by adding 2 mmol H(2)O(2)/min was also investigated and 100 % MCP degradation and 20% TOC removal was obtained. Finally, the degradation and mineralization of 300 mg/L MCP solution (6 g/L NaCl, 93 A/m(2)) by the electro-Fenton process using Fe electrodes by adding 2 mmol H(2)O(2)/min was performed. It was observed that MCP was degraded completely in less than 5 min and was mineralized up to the yields of 66% efficiency for 90 min.
BibTeX:
@article{Yatmaz2009,
  author = {Yatmaz, H. C. and Uzman, Y.},
  title = {Degradation of Pesticide Monochrotophos from Aqueous Solutions by Electrochemical Methods},
  journal = {International Journal of Electrochemical Science},
  year = {2009},
  volume = {4},
  number = {5},
  pages = {614--626},
  url = {://WOS:000267341100001}
}
Akyol A and Bayramoglu M (2008), "The degradation of an azo dye in a batch slurry photocatalytic reactor", Chemical Engineering and Processing. Vol. 47(12), pp. 2150-2156.
Abstract: The photocatalytic degradation of a commercial azo-reactive textile dye, Remazol Red F-3B, has been investigated in a batch slurry reactor using semiconductor catalysts like, ZnO and TiO(2), and two UV sources emitting mainly at 254 and 365 rim. Non-irradiated catalysts and non-catalyzed UV irradiation have negligible effect on the dye degradation. Initial pH. dye concentration, light power and catalyst loading as well as the catalyst type and UV wavelength are considered as process variables. The results showed that decolorization and TOC removal efficiencies of ZnO are higher under 365 nm UV. On the other hand, when two photocatalysts are compared, the decolorization performance of ZnO is higher than TiO(2) under 365 nm UV. while TiO(2) performs better under 254 nm UV. Furthermore, from the TOC removal point, TiO(2) performs better than ZnO irrespective of the UV wavelength. TiO(2) irradiated under 254 nm UV degrades successfully both benzene and naphthalene derivatives. (C) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Akyol2008,
  author = {Akyol, A. and Bayramoglu, M.},
  title = {The degradation of an azo dye in a batch slurry photocatalytic reactor},
  journal = {Chemical Engineering and Processing},
  year = {2008},
  volume = {47},
  number = {12},
  pages = {2150--2156},
  url = {://WOS:000261134000013},
  doi = {10.1016/j.cep.2007.11.002}
}
Demirbas E, Kobya M and Sulak MT (2008), "Adsorption kinetics of a basic dye from aqueous solutions onto apricot stone activated carbon", Bioresource Technology. Vol. 99(13), pp. 5368-5373.
Abstract: The preparation of activated carbon from apricot stone with H2SO4 activation and its ability to remove a basic dye, astrazon yellow 7GL, from aqueous solutions were reported in this study-The adsorbent was characterized by FTIR, BET and SEM, respectively. The effects of various experimental parameters, such as initial dye concentration, pH, adsorbent dosage and temperature were investigated in a batch-ad sorption technique. The optimum conditions for removal of the basic dye were found to be pH 10, 6 g/l of adsorbent dosage and equilibrium time of 35 min, respectively. A comparison of three kinetic models, the pseudo first-order, second-order and diffusion controlled kinetic models, on the basic dye-adsorbent system showed that the removal rate was heavily dependent on diffusion controlled kinetic models. The adsorption isotherm data were fitted well to Langmuir and Freundlich isotherms. The adsorption capacity was calculated as 221.23 mg/g at 50 degrees C. Thermodynamics parameters were also evaluated. The values of enthalpy and entropy were 49.87 kJ/mol and 31.93 J/mol K, respectively, indicating that this process was spontaneous and endothermic. The experimental studies were indicated that ASC had the potential to act as an alternative adsorbent to remove the basic dye from aqueous solutions. (C) 2007 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Demirbas2008,
  author = {Demirbas, E. and Kobya, M. and Sulak, M. T.},
  title = {Adsorption kinetics of a basic dye from aqueous solutions onto apricot stone activated carbon},
  journal = {Bioresource Technology},
  year = {2008},
  volume = {99},
  number = {13},
  pages = {5368--5373},
  url = {://WOS:000256654600011},
  doi = {10.1016/j.biortech.2007.11.019}
}
Demirbas E, Kobya M and Konukman AES (2008), "Error analysis of equilibrium studies for the almond shell activated carbon adsorption of Cr(VI) from aqueous solutions", Journal of Hazardous Materials. Vol. 154(1-3), pp. 787-794.
Abstract: In this study, the preparation of activated carbon from almond shell with H2SO4 activation and its ability to remove toxic hexavalent chromium from aqueous solutions are reported. The influences of several operating parameters such as pH, particle size and temperature on the adsorption capacity were investigated. Adsorption of Cr(VI) is found to be highly pH, particle size and temperature dependent. Four adsorption isotherm models namely, Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich were used to analyze the equilibrium data. The Langmuir isotherm provided the best correlation for Cr(VI) onto the almond shell activated carbon (ASC). Adsorption capacity was calculated from the Langmuir isotherm as 190.3 mg/g at 323 K. Thermodynamic parameters were evaluated and the adsorption was endothermic showing monolayer adsorption of Cr(VI). Five error functions were used to treat the equilibrium data using non-linear optimization techniques for evaluating the fit of the isotherm equations. The highest correlation for the isotherm equations in this system was obtained for the Freundlich isotherm. ASC is found to be inexpensive and effective adsorbent for removal of Cr(VI) from aqueous solutions. (C) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Demirbas2008a,
  author = {Demirbas, E. and Kobya, M. and Konukman, A. E. S.},
  title = {Error analysis of equilibrium studies for the almond shell activated carbon adsorption of Cr(VI) from aqueous solutions},
  journal = {Journal of Hazardous Materials},
  year = {2008},
  volume = {154},
  number = {1-3},
  pages = {787--794},
  url = {://WOS:000256111200101},
  doi = {10.1016/j.jhazmat.2007.10.094}
}
Dizge N, Keskinler B and Tanriseven A (2008), "Covalent attachment of microbial lipase onto microporous styrene-divinylbenzene copolymer by means of polyglutaraldehyde", Colloids and Surfaces B-Biointerfaces. Vol. 66(1), pp. 34-38.
Abstract: A novel method for immobilization of Thermomyces lanuginosus lipase onto polyglutaraldehyde-activated polystyrene-divinylbenzene) (STY-DVB), which is a hydrophobic microporous support has been successfully developed. The copolymer was prepared by the polymerization of the continuous phase of a high internal phase emulsion (polyHIPE). The concentrated emulsion consists of a mixture of styrene and divinylbenzene containing a suitable surfactant and an initiator as the continuous phase and water as the dispersed phase. Lipase from T lanuginosus was immobilized covalently with 85% yield on the internal surface of the hydrophobic microporous polystyrene-divinylbenzene) copolymer and used as a biocatalyst for the transesterification reaction. The immobilized enzyme has been fully active 30 days in storage and retained the activity during the 15 repeated batch reactions. The properties of free and immobilized lipase were studied. The effects of protein concentration, pH, temperature, and time on the immobilization, activity, and stability of the immobilized lipase were also studied. The newly synthesized microporous polystyrene-divinylbenzene) copolymer constitutes excellent support for lipase. It given rise to high immobilization yield. retains enzymatic activity for 30 days, stable in structure and allows for the immobilization of large amount of protein (11.4 mg/g support). Since immobilization is simple yet effective, the newly immobilized lipase could be used in several application including oil hydrolysis, production of modified oils, biodiesel synthesis, and removal of fatty acids from oils. (c) 2008 Elsevier B.V. All rights reserved.
BibTeX:
@article{Dizge2008,
  author = {Dizge, N. and Keskinler, B. and Tanriseven, A.},
  title = {Covalent attachment of microbial lipase onto microporous styrene-divinylbenzene copolymer by means of polyglutaraldehyde},
  journal = {Colloids and Surfaces B-Biointerfaces},
  year = {2008},
  volume = {66},
  number = {1},
  pages = {34--38},
  url = {://WOS:000258983900005},
  doi = {10.1016/j.colsurfb.2008.05.003}
}
Dizge N and Keskinler B (2008), "Enzymatic production of biodiesel from canola oil using immobilized lipase", Biomass & Bioenergy. Vol. 32(12), pp. 1274-1278.
Abstract: In the present work, a novel method for immobilization of lipase within hydrophilic polyurethane foams using polyglutaraldehyde was developed for the immobilization of Thermamyces lanuginosus lipase to produce biodiesel with canola oil and methanol. The enzyme optimum conditions were not affected by immobilization and the optimum pH for free and immobilized enzyme were 6, resulting in 80% immobilization yield. Using the immobilized lipase T lanuginosus, the effects of enzyme loading, oil/alcohol molar ratio, water concentration, and temperature in the transesterification reaction were investigated. The optimal conditions for processing 20 g of refined canola oil were: 430 mu g lipase, 1:6 oil/methanol molar ratio, 0.1g water and 40 degrees C for the reactions with methanol. Maximum methyl esters yield was 90% of which enzymatic activity remained after 10 batches, when tert-butanol was adopted to remove by-product glycerol during repeated use of the lipase. The immobilized lipase proved to be stable and lost little activity when was subjected to repeated uses. (C) 2008 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Dizge2008a,
  author = {Dizge, N. and Keskinler, B.},
  title = {Enzymatic production of biodiesel from canola oil using immobilized lipase},
  journal = {Biomass & Bioenergy},
  year = {2008},
  volume = {32},
  number = {12},
  pages = {1274--1278},
  url = {://WOS:000261903700023},
  doi = {10.1016/j.biombioe.2008.03.005}
}
Dizge N, Gunaydin O, Yilmaz F and Tanriseven A (2008), "Immobilization of invertase onto poly (3-methylthienyl methacrylate)/poly (3-thiopheneacetic acid) matrix", Biochemical Engineering Journal. Vol. 40(1), pp. 64-71.
Abstract: A novel immobilization matrix, poly(3-methylthienyl methacrylate)-poly(3-thioplieneacetic acid) (PMTM-PTAA), was synthesized and used for the covalent immobilization of Saccharomyces cerevisiae invertase to produce invert sugar. The immobilization resulted in 87% immobilization efficiency. Optimum conditions for activity were not affected by immobilization and the optimum pH and temperature for both free and immobilized enzyme were found to be 4.5 and 55 degrees C, respectively. However, immobilized invertase was more stable at high pH and temperatures. The kinetic parameters for free and immobilized invertase were also determined using the Lineweaver-Burk plot. The K-m values were 35 and 38 mM for free and immobilized enzyme, respectively. The V-max values were 29 and 24 mg glucose/mg enzyme min for free and immobilized enzyme, respectively. Immobilized enzyme could be used for the production of glucose and fructose from sucrose since it retained almost all the initial activity for a month in storage and retained the whole activity in repeated 50 batch reactions. (c) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Dizge2008b,
  author = {Dizge, N. and Gunaydin, O. and Yilmaz, F. and Tanriseven, A.},
  title = {Immobilization of invertase onto poly (3-methylthienyl methacrylate)/poly (3-thiopheneacetic acid) matrix},
  journal = {Biochemical Engineering Journal},
  year = {2008},
  volume = {40},
  number = {1},
  pages = {64--71},
  url = {://WOS:000256607500008},
  doi = {10.1016/j.bej.2007.11.017}
}
Dizge N, Aydiner C, Demirbas E, Kobya M and Kara S (2008), "Adsorption of reactive dyes from aqueous solutions by fly ash: Kinetic and equilibrium studies", Journal of Hazardous Materials. Vol. 150(3), pp. 737-746.
Abstract: Adsorption kinetic and equilibrium studies of three reactive dyes namely, Remazol Brillant Blue (RB), Remazol Red 133 (RR) and Rifacion Yellow HED (RY)from aqueous solutions at various initial dye concentration (100-500 mg/l), pH(2-8), particle size (45-112.5 mu m) and temperature (293-323 K) on fly ash (FA) were studied in a batch mode operation. The adsorbent was characterized with using several methods such as SEM, XRD and FTIR. Adsorption of RB reactive dye was found to be pH dependent but both RR and RY reactive dyes were not. The result showed that the amount adsorbed of the reactive dyes increased with increasing initial dye concentration and contact time. Batch kinetic data from experimental investigations on the removal of reactive dyes from aqueous solutions using FA have been well described by external mass transfer and intraparticle diffusion models. It was found that external mass transfer and intraparticle diffusion had rate limiting affects on the removal process. This was attributed to the relatively simple macropore structure of FA particles. The adsorption data fitted well with Langmuir and Freundlich isotherm models. The optimum conditions for removal of the reactive dyes were 100 mg/l initial dye concentration, 0.6 g/100 ml adsorbent dose, temperature of 293 K, 45 mu m particle size, pH 6 and agitation speed of 250 rpm, respectively. The values of Langmuir and Freundlich constants were found to increase with increasing temperature in the range 135-180 and 15-34 mg/g for RB, 47-86 and 1.9-3.7 mg/g for RR and 37-61 and 3.0-3.6 mg/g for RY reactive dyes, respectively. Different thermodynamic parameters viz., changes in standard free energy, enthalpy and entropy were evaluated and it was found that the reaction was spontaneous and endothermic in nature. (c) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Dizge2008c,
  author = {Dizge, N. and Aydiner, C. and Demirbas, E. and Kobya, M. and Kara, S.},
  title = {Adsorption of reactive dyes from aqueous solutions by fly ash: Kinetic and equilibrium studies},
  journal = {Journal of Hazardous Materials},
  year = {2008},
  volume = {150},
  number = {3},
  pages = {737--746},
  url = {://WOS:000253219500033},
  doi = {10.1016/j.jhazmat.2007.05.027}
}
Ince M, Yildiz F, Engin GO, Engin SN and Keskinler B (2008), "Respirometric kinetic parameter calculations of a batch jet loop bioreactor treating leachate and oxygen uptake rate estimation by DTM", Journal of Hazardous Materials. Vol. 153(3), pp. 991-998.
Abstract: A novel circulating jet loop bioreactor adapted for organic matter oxidation has been designed and constructed. In this study, the input was leachate samples collected from Kemerburgaz Odayeri waste landfill site located on the European side of Istanbul. Controlling the jet loop bioreactor to realize high rates of purification depends on maintaining the appropriate loadings and operating conditions. This requires collecting various system data to estimate the dynamics of the system satisfactorily with the aim of keeping certain parameters within the specified range. The differential transform method (DTM) based solution of the state equations reveals the current state of the process so that any deviation in the system parameters can be immediately detected and regulated accordingly. The respirometric method for kinetic parameter calculations for biodegradation has been used for some time. In many studies, the respirometer was designed separately, usually in bench-scale. However, when a separate respirometer is used, the scale effect and parameters that affect the hydrodynamic structure of the system should be taken into consideration. In this study, therefore, the jet loop reactor itself was used as a respirometer. Thus, the kinetic parameters found reflecting the characteristics of microorganisms used for biodegradation would be more realistic. If the main reactor, here the jet loop reactor, would be used as the respirometer, the kinetic parameter changes can easily be monitored in the long run. Using the bioreactor as a respirometer, the most important kinetic parameters, K(s), k(d) and mu(max) were found to be 11,000 mg L(-1), 0.019 day(-1), and 0.21 day(-1), respectively. The stoichiometric coefficient, Y, was found to be 0.28 gr gr(-1) for the present system. (C) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Ince2008,
  author = {Ince, M. and Yildiz, F. and Engin, G. O. and Engin, S. N. and Keskinler, B.},
  title = {Respirometric kinetic parameter calculations of a batch jet loop bioreactor treating leachate and oxygen uptake rate estimation by DTM},
  journal = {Journal of Hazardous Materials},
  year = {2008},
  volume = {153},
  number = {3},
  pages = {991--998},
  url = {://WOS:000255544300012},
  doi = {10.1016/j.jhazmat.2007.09.069}
}
Kobya M and Delipinar S (2008), "Treatment of the baker's yeast wastewater by electrocoagulation", Journal of Hazardous Materials. Vol. 154(1-3), pp. 1133-1140.
Abstract: In the laboratory-scale experiments, treatment of baker's yeast production wastewater has been investigated by electrocoagulation (EC) using a batch reactor. Effects of the process variables such as pH, electrode material (Fe and Al), current density, and operating time are investigated in terms of removal efficiencies of chemical oxygen demand (COD), total organic carbon (TOC), turbidity, and operating cost, respectively. The maximum removal efficiencies of COD, TOC and turbidity under optimal operating conditions, i.e., pH 6.5 for Al electrode and pH 7 for Fe electrode, current density of 70 A/m(2) and operating time of 50 min were 71, 53 and 90% for Al electrode and 69, 52 and 56% for Fe electrode, respectively. Al electrode gave 4.4 times higher removal efficiency of turbidity than Fe electrode due to interference from color of dissolved iron. The operating costs for Al and Fe electrodes in terms of $/m(3) or $/kg COD were 1.54 and 0.82, 0.51 and 0.27, respectively. (c) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kobya2008,
  author = {Kobya, M. and Delipinar, S.},
  title = {Treatment of the baker's yeast wastewater by electrocoagulation},
  journal = {Journal of Hazardous Materials},
  year = {2008},
  volume = {154},
  number = {1-3},
  pages = {1133--1140},
  url = {://WOS:000256111200143},
  doi = {10.1016/j.jhazmat.2007.11.019}
}
Kobya M, Ciftci C, Bayramoglu M and Sensoy MT (2008), "Study on the treatment of waste metal cutting fluids using electrocoagulation", Separation and Purification Technology. Vol. 60(3), pp. 285-291.
Abstract: Electrocoagulation (EC) technique is applied for the treatment of waste metal cutting fluids (WMCFs) characterized by high COD and TOC concentration, discharged from metal manufacturing facilities including automotive engine, transmission, and stamping plants. The effects of initial pH, current density and operating time on the performance of EC are investigated by using sacrificial A] and Fe electrodes. Upon treatment by EC, the COD of WMCF is reduced by 93% and the TOC is reduced by 78% for At electrode at pH 5.0, current density of 60 A/m(2) and operating time of 25 min. For Fe electrode, the reduction in COD is 92% and reduction in TOC is 82% at pH 7.0, current density of 60 A/m(2) and operating time of 25 min. Under optimal operating conditions, the operating costs are calculated as 0.497 $/m(3) (0.023 $/kg removed COD or 0.144 $/kg removed TOC) for Fe electrode, and 0.768 $/m(3) (0.036 $/kg removed COD or 0.228$/kg removed TOC) for Al electrode. Fe electrode is found to be more efficient than At electrode in terms of parameters such as COD and TOC removal efficiencies and operating costs. (c) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kobya2008a,
  author = {Kobya, M. and Ciftci, C. and Bayramoglu, M. and Sensoy, M. T.},
  title = {Study on the treatment of waste metal cutting fluids using electrocoagulation},
  journal = {Separation and Purification Technology},
  year = {2008},
  volume = {60},
  number = {3},
  pages = {285--291},
  url = {://WOS:000255820300010},
  doi = {10.1016/j.seppur.2007.09.003}
}
Koparal AS, Yildiz YS, Keskinler B and Demircioglu N (2008), "Effect of initial pH on the removal of humic substances from wastewater by electrocoagulation", Separation and Purification Technology. Vol. 59(2), pp. 175-182.
Abstract: This investigation deals with the effect of initial pH batch removal of synthetically prepared wastewater having high concentration of humic substances by electrocoagulation method using plate electrodes. The effects of initial pH on an electrocoagulation system may be twofold. These are distribution of aluminum hydrolysis product, transformation of humic substance related to the initial pH and finally the effects of the gel layer especially in high humic substance concentrations and high initial pH formed on the anode surface. It has been observed that initial humic substance concentration and initial pH are highly effective on the removal rate and efficiency. For example, in the range of 200-500 mg L-1, decrese in the removal efficiency was observed due to gel layer formation on the surface of the anode surface. This get formation especially starts at an initial concentration of 120 ing L-1; thickness and effect of the layer increase as concentration increases. In order to prevent this gel formation, initial pH of the wastewater was adjusted to 5.0 and high removal efficiencies were observed. Thus, the system should be operated at low pH values (i.e. 5.0) at high concentrations. (C) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Koparal2008,
  author = {Koparal, A. S. and Yildiz, Y. S. and Keskinler, B. and Demircioglu, N.},
  title = {Effect of initial pH on the removal of humic substances from wastewater by electrocoagulation},
  journal = {Separation and Purification Technology},
  year = {2008},
  volume = {59},
  number = {2},
  pages = {175--182},
  url = {://WOS:000253327400008},
  doi = {10.1016/j.seppur.2007.06.004}
}
Korkut S, Keskinler B and Erhan E (2008), "An amperometric biosensor based on multiwalled carbon nanotube-poly(pyrrole)-horseradish peroxidase nanobiocomposite film for determination of phenol derivatives", Talanta. Vol. 76(5), pp. 1147-1152.
Abstract: An amperometric biosensor based on horseradish peroxidase (HRP) and carbon nanotube (CNT)/polypyrrole(PPy) nanobiocomposite film on a gold surface has been developed. The HRP was incorporated into the CNT/PPy nanocomposite matrix in one-step electropolymerization process without the aid of cross-linking agent. Amperometric response was measured as a function of concentration of phenol derivatives, at a fixed bias voltage of -50mV. Optimization of the experimental parameters was performed with regard to pH and concentration of hydrogen peroxide. The linear range, sensitivity and detection limit of the biosensor were investigated for eighteen phenol derivatives. The sensitivity in the linear range increased in this order: 4-methoxyphenol > 2-aminophenol > guaiacol = m-cresol > 2-chlorophenol = 4-chlorophenol = hydroquinone = pyrocatechol > 2,6-dimethoxyphenol > 3-chlorophenol > p-cresol > p-benzoquinone = 4-acetamidophenol > catechol > phenol = pyrogallol = 2,4-dimethylphenol. CNTs was shown to enhance the electron transfer as a mediator and capable to carry higher bioactivity owing to its intensified surface area. The biosensor exhibited low detection limits with a short response time (2s) for the tested phenolics compared to the reported working electrodes. It retained 70% of its initial activity after using for 700 measurements in 1 month. (C) 2008 Elsevier B.V. All rights reserved.
BibTeX:
@article{Korkut2008,
  author = {Korkut, S. and Keskinler, B. and Erhan, E.},
  title = {An amperometric biosensor based on multiwalled carbon nanotube-poly(pyrrole)-horseradish peroxidase nanobiocomposite film for determination of phenol derivatives},
  journal = {Talanta},
  year = {2008},
  volume = {76},
  number = {5},
  pages = {1147--1152},
  url = {://WOS:000259750800027},
  doi = {10.1016/j.talanta.2008.05.016}
}
Oguz E, Tortum A and Keskinler B (2008), "Determination of the apparent rate constants of the degradation of humic substances by ozonation and modeling of the removal of humic substances from the aqueous solutions with neural network", Journal of Hazardous Materials. Vol. 157(2-3), pp. 455-463.
Abstract: In this study, the degradation rate constants of humic substances by ozonation under the different empirical conditions such as ozone-air flow rate, ozone generation potential, pH, temperature, powdered activated carbon (PAC) dosage and HCO3- ions concentration were determined. The ozonation of humic substances in the semi-batch reactor was found to fit pseudo-first-order reaction. The values of apparent rate constant of humic substances degradation increased with the increase of initial ozone-air flow rates, ozone generation potential, pH, temperatures and PAC dosage, but decreased with the increase of HCO3- concentration of the solution: Using Arrhenius equation, the activation energy (E) of the reaction was found as 1.96 kJ mol(-1). The reaction of ozonation of humic substances under the different temperatures was defined as diffusion control according to E.. The model based on artificial neural network (ANN) could predict the concentrations of humic substances removal from aqueous solution during ozonation. A relationship between the predicted results of the designed ANN model and experimental data was also conducted. The ANN model yielded determination coefficient of (R-2=0.995), standard deviation ratio (0.065), mean absolute error (4.057) and root mean square error (5.4967). (C) 2008 Elsevier B.V. All rights reserved.
BibTeX:
@article{Oguz2008,
  author = {Oguz, E. and Tortum, A. and Keskinler, B.},
  title = {Determination of the apparent rate constants of the degradation of humic substances by ozonation and modeling of the removal of humic substances from the aqueous solutions with neural network},
  journal = {Journal of Hazardous Materials},
  year = {2008},
  volume = {157},
  number = {2-3},
  pages = {455--463},
  url = {://WOS:000258425900031},
  doi = {10.1016/j.jhazmat.2008.01.018}
}
Oguz E, Keskinler B and Tortum A (2008), "Determination of the apparent ozonation rate constants of 1 : 2 metal complex dyestuffs and modeling with a neural network", Chemical Engineering Journal. Vol. 141(1-3), pp. 119-129.
Abstract: In this study, the apparent ozonation rate constants of 1:2 metal complex dyestuffs under different empirical conditions such as dye concentrations (400-1000 ppm), ozone-air flow rates (5-15 l min(-1)), the percentages Of 03 in the ozone-air flow rate (0.7-1.4), pH (3-12), temperatures (18-70 degrees C), powder activated carbon (PAC) (0.5-1.5 g in solution of 250 ml), HCO3- (0-26 mM) and H2O2 concentrations (0-21 mM) were determined. The ozonation of 1:2 metal complex dyestuffs was found to be fit pseudo-first-order reaction, and the apparent rate constants did not change with the increase of dyestuffs concentrations. For 1:2 metal complex dyestuffs, the apparent rate constants of dyestuffs degradation by ozonation increased with the augmentation of initial pH, H2O2, the percentage of O-3 in the ozone-air flow rate and PAC dosage in the solution, but decreased with the increase of HCO3- concentration and temperature of the solution. The apparent rate constant of dyestuffs degradation by ozonation increased with the augmentation of ozone-air flow rate from 5 to 10 l min(-1), but it did not change in the range of 10-15 l min(-1). At a high pH, the ozonation of 1:2 metal complex dyestuffs contributed to the increase the apparent rate constant due to the occurrence of hydroxyl free radicals. Using Arrhenius equation, the activation energy (E-a) of the reaction was found as 3 kJ mol(-1). The reaction of the ozonation of the dyestuffs under the different temperatures (291, 3 13 and 343 K) was defined as diffusion controlled according to E.,,. The model based on artificial neural network (ANN) could predict the concentrations of the dyestuffs removal from the aqueous solution during ozonation under the different conditions. A relationship between the predicted results of the designed ANN model and the experimental data was also conducted. The ANN model yielded 11 determination coefficient of R-2 = 0.978, a standard deviation ratio of 0.146, a mean absolute error of 19.503 and a root mean square error of 56.600. (C) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Oguz2008a,
  author = {Oguz, E. and Keskinler, B. and Tortum, A.},
  title = {Determination of the apparent ozonation rate constants of 1 : 2 metal complex dyestuffs and modeling with a neural network},
  journal = {Chemical Engineering Journal},
  year = {2008},
  volume = {141},
  number = {1-3},
  pages = {119--129},
  url = {://WOS:000257572900014},
  doi = {10.1016/j.cej.2007.11.002}
}
Oguz E and Keskinler B (2008), "Removal of colour and COD from synthetic textile wastewaters using O-3, PAC, H2O2 and HCO3", Journal of Hazardous Materials. Vol. 151(2-3), pp. 753-760.
Abstract: This study aimed to investigate removal of colour and chemical oxygen demand (COD) from synthetic textile wastewaters using 03, powder activated carbon (PAC), H2O2 and HCO3- in a semi-batch reactor. 1:2 metal complex dyestuffs containing two molecules of dyestuffs versus a chromium atom was used. Experiments were conducted under the various pHs (3-12), temperatures (18-70 degrees C), ozone doses (164-493 mg min(-1)). The combined effect of substances used on the removal of colour and COD was investigated. The mechanisms of colour and COD removal on the PAC were explained on the basis of the results of Fourier transform infrared spectroscopy (FTIR). In addition, the zeta potential values of PAC, ozonated PAC and ozonated PAC contaminated with intermediates were determined. The zeta potential values and FTIR plots of PAC particulates showed that PAC acted as an adsorbent in the combined processes. It was thought that all of the substances used in the semi-batch reactor had the combined effect on the removal of colour and COD because of the short treatment time of 5 min and high efficiencies of the removal of colour and COD. The efficiencies of removal of colour and COD in combination were compared with adsorption and ozonation only. In this study, the efficiencies of colour and COD removal during a reaction time of 30 min were obtained as 99 and 95 %, respectively. At the result of this study, it was concluded that 03, PAC and H2O2 were an important substances for the removal of colour and COD from synthetic textile wastewater when they were used in combination. (C) 2007 Published by Elsevier B.V.
BibTeX:
@article{Oguz2008b,
  author = {Oguz, E. and Keskinler, B.},
  title = {Removal of colour and COD from synthetic textile wastewaters using O-3, PAC, H2O2 and HCO3},
  journal = {Journal of Hazardous Materials},
  year = {2008},
  volume = {151},
  number = {2-3},
  pages = {753--760},
  url = {://WOS:000253829200058},
  doi = {10.1016/j.jhazmat.2007.06.045}
}
Okay S, Tefon BE, Ozkan M and Ozcengiz G (2008), "Expression of chitinase A (chiA) gene from a local isolate of Serratia marcescens in Coleoptera-specific Bacillus thuringiensis", Journal of Applied Microbiology. Vol. 104(1), pp. 161-170.
Abstract: Aims: The present study focused on cloning and expression of chiA gene from a highly chitinolytic local isolate of Serratia marcescens in an anti-Coleopteran Bacillus thuringiensis and comparison of the characteristics of the native and recombinant ChiAs. Methods and Results: chiA gene from Ser. marcescens was cloned, sequenced and compared with the previously cloned chiA genes. chiA gene was PCR cloned and expressed in anti-Coleopteran B. thuringiensis strain 3023 as verified by Western blot analysis. Specific ChiA activity of the recombinant B. thuringiensis (strain 3023-SCHI) reached its highest level at 21st hour of growth (16.93 U mg(-1)), which was 5.2- and 1.3-fold higher than that of its parental strain and Ser. marcescens, respectively. Temperature and pH effects on native and recombinant ChiAs were next determined. The recombinant plasmid was quite stable over 240 generations. Conclusions: Serratia marcescens ChiA was heterologously expressed in an anti-Coleopteran B. thuringiensis at levels even higher than that produced by the source organism. Significance and Impact of the Study: Bacillus thuringiensis 3023-SCHI co-expressing anti-Coleopteran Cry3Aa protein and Ser. marcescens chitinase offers a viable alternative to the use of chitinolytic microbes/enzymes in combination with entamopathogenic bacteria for an increased potency because of synergistic interaction between them.
BibTeX:
@article{Okay2008,
  author = {Okay, S. and Tefon, B. E. and Ozkan, M. and Ozcengiz, G.},
  title = {Expression of chitinase A (chiA) gene from a local isolate of Serratia marcescens in Coleoptera-specific Bacillus thuringiensis},
  journal = {Journal of Applied Microbiology},
  year = {2008},
  volume = {104},
  number = {1},
  pages = {161--170},
  url = {://WOS:000251670600016},
  doi = {10.1111/j.1365-2672.2007.03570.x}
}
Oncel MS (2008), "Adsorption of copper(II) from aqueous solution by Beidellite", Environmental Geology. Vol. 55(8), pp. 1767-1775.
Abstract: Beidellite was used as an adsorbent for the removal of copper ions from aqueous solutions. Batch mode studies were carried out by varying initial copper (II) concentrations (50-500 mg/l), initial pH (2.0-5.0), adsorbent particle size (0.095-0.890 mm) and temperature (293-333 K). A contact time of 60 min was required to reach equilibrium. Adsorption of the metal ion was highly pH dependent and the optimum pH for the removal was 5.0 at which the removal was maximum (25.3 mg/g). The result showed that the amount adsorbed of the metal ion increased with increasing initial copper (II) concentration and contact time. Three adsorption kinetic models, the pseudo first-order, second-order and intraparticle diffusion were applied to experimental data to predict the adsorption rate constants. A comparison of kinetic models on the overall adsorption rate showed that metal ion/adsorbent system was best described by the pseudo second-order rate model. The adsorption capacity (Q (o)) calculated from the Langmuir isotherm was 71.07 mg/g for at pH 5.0, 293 K for the particle size of 0.095-0.890 mm. The experimental data yielded excellent fits with Langmuir isotherm equation. Different thermodynamic parameters viz., changes in standard free energy, enthalpy and entropy were evaluated and it was found that the reaction was spontaneous and endothermic in nature.
BibTeX:
@article{Oncel2008,
  author = {Oncel, M. S.},
  title = {Adsorption of copper(II) from aqueous solution by Beidellite},
  journal = {Environmental Geology},
  year = {2008},
  volume = {55},
  number = {8},
  pages = {1767--1775},
  url = {://WOS:000259730000014},
  doi = {10.1007/s00254-007-1127-6}
}
Sayiner G, Kandemirli F and Dimoglo A (2008), "Evaluation of boron removal by electrocoagulation using iron and aluminum electrodes", Desalination. Vol. 230(1-3), pp. 205-212.
Abstract: Boron compounds are used in the variety of products manufacturing and are introduced to the environment in the form of waste. Here the feasibility of the boron removal from wastewater by electrocoagulation (EC) is studied. Aluminum and iron were simultaneously used in the reactor as materials for cathode and anode. The results show that the EC process for boron removal strongly depends on the current density, initial concentrations, and time. The process is examined under varying indices in order to determine optimal operating conditions. It is important to note the EC application needs no chemical reagents and makes the boron-containing wastewater treatment easy for regulation and automation.
BibTeX:
@article{Sayiner2008,
  author = {Sayiner, G. and Kandemirli, F. and Dimoglo, A.},
  title = {Evaluation of boron removal by electrocoagulation using iron and aluminum electrodes},
  journal = {Desalination},
  year = {2008},
  volume = {230},
  number = {1-3},
  pages = {205--212},
  url = {://WOS:000260286900019},
  doi = {10.1016/j.desal.2007.10.020}
}
Tekbas M, Yatmaz HC and Bektas N (2008), "Heterogeneous photo-Fenton oxidation of reactive azo dye solutions using iron exchanged zeolite as a catalyst", Microporous and Mesoporous Materials. Vol. 115(3), pp. 594-602.
Abstract: The heterogeneous photo-Fenton-type oxidation of reactive azo dye solutions has been investigated in a quartz batch reactor using artificial UVA as a light source. Fe-exchanged zeolite has been used as a heterogeneous catalyst in the process. The effect of various process variables on decolorization performance of the process was evaluated by examining temperature, pH, H(2)O(2) dosage, catalyst loading, initial dye concentration and light intensity. The optimal operational parameters were found as follows: 35 degrees C, pH as solution pH 5.2, 15 mmol H(2)O(2) dosage, 1 g/L catalyst loading. Stability and reuse of the catalyst were also tested. Mineralization and comparison with homogenous photo-Fenton process were evaluated by analyzing color removal and total organic carbon (TOC) values. (c) 2008 Elsevier Inc. All rights reserved.
BibTeX:
@article{Tekbas2008,
  author = {Tekbas, M. and Yatmaz, H. C. and Bektas, N.},
  title = {Heterogeneous photo-Fenton oxidation of reactive azo dye solutions using iron exchanged zeolite as a catalyst},
  journal = {Microporous and Mesoporous Materials},
  year = {2008},
  volume = {115},
  number = {3},
  pages = {594--602},
  url = {://WOS:000259845000045},
  doi = {10.1016/j.micromeso.2008.03.001}
}
Uyar G, Oren M, Yildirim Y and Oncel S (2008), "Biomonitoring of Metal Deposition in the Vicnity of Eregli Steel Plant in Turkey", Environmental Forensics. Vol. 9(4), pp. 350-363.
Abstract: This article describes the first attempt to study the concentration of seven element (Fe, Pb, Ni, Cr, Cu, Co, and As) contaminations in the vicinity of the Eregli Iron and Steel Plant (ERDEMIR) by analysis of two pleurocarpic moss species (Hypnum cupressiforme and Scleropodium purum). Samples of H. cupressiforme were collected from May 2003 to October 2004. Unwashed, dried samples were digested with HNO3/HClO4, and the concentrations of heavy metals were determined by graphite-furnace atomic absorption spectrometry (GFAAS). In the region, general orders of heavy metal content in samples of mosses were determined as follows: Fe Pb Cr Ni Cu Co As. Comparisons were made between the two moss species for those elements presents at different concentrations and regression analysis were made to see interspecies relationship. H. cupressiforme and S. purum are significantly correlated for only Fe (P 0.01) having Pearson's correlation coefficient as 0.93, indicating interspecies calibration for Fe. The ratios (Hc/Sp) were relatively better correlated with 1/Sp for As than for other metals, suggesting a saturation effect in H. cupressiforme for As. The deposition of metals due to the operation of the steel plant has been established and could be further monitored. Such information could be useful for forensic studies aiming to apportion between different possible sources of those metals.
BibTeX:
@article{Uyar2008,
  author = {Uyar, G. and Oren, M. and Yildirim, Y. and Oncel, S.},
  title = {Biomonitoring of Metal Deposition in the Vicnity of Eregli Steel Plant in Turkey},
  journal = {Environmental Forensics},
  year = {2008},
  volume = {9},
  number = {4},
  pages = {350--363},
  url = {://WOS:000261675300008},
  doi = {10.1080/15275920802122783}
}
Veli S, Ozturk T and Dimoglo A (2008), "Treatment of municipal solid wastes leachate by means of chemical- and electro-coagulation", Separation and Purification Technology. Vol. 61(1), pp. 82-88.
Abstract: In this study, treatment of municipal solid waste leachate (L1, L2) by means of chemical- and electro-coagulation (EC) methods was investigated. The removal of chemical oxygen demand (COD), total organic carbons (TOC) and color from leachate was experimentally investigated by using chemical- and electro-coagulation. Aluminum and iron were used simultaneously in the reactor as materials for electrodes. Percent of COD, TOC and color removal versus the electro-chemically generated Fe(2+) and Al(3+) doses are examined in this study. The best removal has been achieved in the COD parameter. Thus, in electro-coagulation method, the maximal removal is 87% for the L1 solution, while for L2 it is 90% for Fe(2+) and 77% for L1 and 88% for L2 for Al(3+) ion solutions. High color removal for Fe,21 is observed for L1 (86%), while for L2 it is approximately 99%. The removal indices for the leachate treatment by chemical coagulants (FeSO(4)center dot 7H(2)O and Al(2)(SO(4))(3)center dot 18H(2)O) appeared to be lower than for the electrochemically generated Fe(2+) and Al(3+). The results show that electro-coagulation could be considered as an effective alternative solution for the treatment of leachate. (C) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Veli2008,
  author = {Veli, S. and Ozturk, T. and Dimoglo, A.},
  title = {Treatment of municipal solid wastes leachate by means of chemical- and electro-coagulation},
  journal = {Separation and Purification Technology},
  year = {2008},
  volume = {61},
  number = {1},
  pages = {82--88},
  url = {://WOS:000256116500011},
  doi = {10.1016/j.seppur.2007.09.026}
}
Yassitepe E, Yatmaz HC, Ozturk C, Ozturk K and Duran C (2008), "Photocatalytic efficiency of ZnO plates in degradation of azo dye solutions", Journal of Photochemistry and Photobiology a-Chemistry. Vol. 198(1), pp. 1-6.
Abstract: Tape casting method was used to prepare ZnO plates for photocatalytic degradation of Reactive Orange 16 (RO 16) and Reactive Red 180 (RR 180) textile dyes in aqueous solutions. The plates were sintered at 700 degrees C and 1050 degrees C and characterized by using TG-DTA, BET and SEM. The sintering process at 700 degrees C yields relatively high surface area ZnO plates comparing with the plates sintered at 1050 degrees C. The photocatalytic activity was enhanced when the high surface area plates were used in photocatalytic degradation processes. Up to 95.7% and 88.6% color removal was obtained in 90min for the RR 180 and RO 16 aqueous solutions, respectively, when the plates were sintered at 700 degrees C. Total organic carbon (TOC) removal was 43% at 180 min for RR 180 solution. Photocorrosion tendency was observed to some extend during photocatalysis when multiple tests were performed on the same plate. This corrosive effect was recovered by the memory effect when the plates were subjected to dark interval overnight. (c) 2008 Elsevier B.V. All rights reserved.
BibTeX:
@article{Yassitepe2008,
  author = {Yassitepe, E. and Yatmaz, H. C. and Ozturk, C. and Ozturk, K. and Duran, C.},
  title = {Photocatalytic efficiency of ZnO plates in degradation of azo dye solutions},
  journal = {Journal of Photochemistry and Photobiology a-Chemistry},
  year = {2008},
  volume = {198},
  number = {1},
  pages = {1--6},
  url = {://WOS:000257036700001},
  doi = {10.1016/j.jphotochem.2008.02.007}
}
Yildiz YS, Koparal AS and Keskinler B (2008), "Effect of initial pH and supporting electrolyte on the treatment of water containing high concentration of humic substances by electrocoagulation", Chemical Engineering Journal. Vol. 138(1-3), pp. 63-72.
Abstract: In this study, the effects of supporting electrolyte type and concentration were investigated on the batch removal of water with high concentration of natural organic matter (NOM) by the electrocoagulation method using plate electrodes. It was observed that the addition of supporting electrolyte has a twofold effect which can be summarized as follows: firstly increasing the ionic strength of the water causing compression of the double-layer and secondly raising the electrical conductivity of the water causing more current passing through the circuit under the same applied potential. It was observed that the concentration of 5 mM supporting electrolyte was optimum up to 100 mg/L of NOM, while concentration of 10 mM is more favorable for higher concentrations than 100 mg/L of NOM. In order to determine the most favorable supporting electrolyte type, NaCl, Na2SO4 and NaNO3 were used as supporting electrolyte in the test runs. Under the conditions of initial pH of the solution equal to 5.0 and initial concentration of 100 mg/L NOM, charge loadings were within the range of 2.0934-3.7437 F/m(3) for Na2SO4 and NaCl, respectively. Additionally at the same initial conditions for a treatment period of 9 min specific energy consumptions and removal efficiencies were ranged between the 4.747 and 9.695 kWh/m(3), and between 96.84% and 99.64% for Na2SO4 and NaCl, respectively. Availability of the chloride (Cl-) ions in the water can cause formation of disinfection by-products (DBPs) which are suspected carcinogenic compounds. It can be said that the most favorable supporting electrolyte type is Na2SO4 for this treatment technique. (C) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Yildiz2008,
  author = {Yildiz, Y. S. and Koparal, A. S. and Keskinler, B.},
  title = {Effect of initial pH and supporting electrolyte on the treatment of water containing high concentration of humic substances by electrocoagulation},
  journal = {Chemical Engineering Journal},
  year = {2008},
  volume = {138},
  number = {1-3},
  pages = {63--72},
  url = {://WOS:000255100300008},
  doi = {10.1016/j.cej.2007.05.029}
}
Akkoyunlu A, Demir I, Yuksel E and Eyvaz M (2007), "Anaerobic treatment of biscuit wastewater in an uasb-reactor", Fresenius Environmental Bulletin. Vol. 16(9B), pp. 1201-1206.
Abstract: The upflow anaerobic sludge blanket reactor (UASBR) is efficient in treating wastewater, especially when dissolved organic matter is present. In this study, a laboratory scale of an UASBR was configured to treat biscuit wastewater. Hydraulic retention time (HRT), organic loading and hydraulic loading parameters were used as design criteria and wastewater parameters such as pH, alkalinity, chemical oxygen demand (COD), suspended solids (SS), total volatile acid (TVA) and total solids (TS) were investigated as performance criteria. Substrate utilization rate in terms of COD, gas composition in terms of CH(4) and total volatile solids changing with depth in the reactor were also determined. The COD removal rate was attained to be 92%. Methane gas was about 60-65% of the biogas produced. Moreover, a mathematical model was studied and kinetic coefficients were obtained for this particular wastewater. Kinetic coefficient Y and endogenous decay coefficient k(d) were obtained as 0.036 kg TVS/kg COD-rem and 4.084 day(-1), respectively.
BibTeX:
@article{Akkoyunlu2007,
  author = {Akkoyunlu, A. and Demir, I. and Yuksel, E. and Eyvaz, M.},
  title = {Anaerobic treatment of biscuit wastewater in an uasb-reactor},
  journal = {Fresenius Environmental Bulletin},
  year = {2007},
  volume = {16},
  number = {9B},
  pages = {1201--1206},
  url = {://WOS:000250560200010}
}
Bayramoglu M, Eyvaz M and Kobya M (2007), "Treatment of the textile wastewater by electrocoagulation Economical evaluation", Chemical Engineering Journal. Vol. 128(2-3), pp. 155-161.
Abstract: This paper presents the comparative results with respect to electrode configurations on the economic performance of treatment of textile wastewaters by electrocoagulation (EC) process. Aluminum and iron electrode materials were used as sacrificial electrode in parallel and serial connection modes. Various direct and indirect cost items including electrical, sacrificial electrodes, labor, sludge handling, maintenance and depreciation costs were considered in the calculation of the total cost per m(3) of wastewater taken from a textile plant with a capacity of 1000 m(3) per day. The results showed that monopolar-parallel mode (MP-P) was the most cost-effective for Fe and Al electrodes. These electrodes showed similar results in removal efficiency of COD and turbidity, but Fe electrode was preferred due to its low cost. pH 7 for Fe electrode and pH 5 for Al electrode were found suitable in terms of removal efficiency of COD and turbidity from textile wastewater. Meanwhile, 30 Am-2 of current density and 15 min of operating time were found to be sufficient for Fe and Al electrodes. Finally, a comparative study showed that EC was faster and more economic; consumed less material and produced less sludge, and pH of the medium was more stabilized as compared to chemical coagulation (CC) for percentage removal efficiency of COD and turbidity from textile wastewater. The treatment cost of EC at optimum conditions was 3.2 times cheaper than that of CC. (c) 2006 Elsevier B.V. All rights reserved.
BibTeX:
@article{Bayramoglu2007,
  author = {Bayramoglu, M. and Eyvaz, M. and Kobya, M.},
  title = {Treatment of the textile wastewater by electrocoagulation Economical evaluation},
  journal = {Chemical Engineering Journal},
  year = {2007},
  volume = {128},
  number = {2-3},
  pages = {155--161},
  url = {://WOS:000246060400009},
  doi = {10.1016/j.cej.2006.10.008}
}
Bilgili MS, Demir A, Ince M and Ozkaya B (2007), "Metal concentrations of simulated aerobic and anaerobic pilot scale landfill reactors", Journal of Hazardous Materials. Vol. 145(1-2), pp. 186-194.
Abstract: Leachate and solid waste samples from aerobic and anaerobic simulated landfill reactors operated with and without leachate recirculation were characterized in terms of metals such as Fe, Ca, K, Na, Cd, Cr, Cu, Pb, Ni, and Zn. Metal concentrations of aerobic landfill reactor leachate samples are always below the regulation limits. The higher concentrations in anaerobic landfill leachate samples decreased to regulation limits after the landfill becomes methanogenic. The effect of leachate recirculation is determined in anaerobic landfills more clearly than aerobic landfills. Metal precipitation resulted in a decrease in leachate metal content and an increase in solid waste metal content as expected. Result of the study show that the metal content of landfill leachate samples is not a major concern for both aerobic and anaerobic landfills. (c) 2006 Elsevier B.V. All rights reserved.
BibTeX:
@article{Bilgili2007,
  author = {Bilgili, M. S. and Demir, A. and Ince, M. and Ozkaya, B.},
  title = {Metal concentrations of simulated aerobic and anaerobic pilot scale landfill reactors},
  journal = {Journal of Hazardous Materials},
  year = {2007},
  volume = {145},
  number = {1-2},
  pages = {186--194},
  url = {://WOS:000247702200024},
  doi = {10.1016/j.jhazmat.2006.11.014}
}
Farizoglu B, Keskinler B, Yildiz E and Nuhoglu A (2007), "Simultaneous removal of C, N, P from cheese whey by jet loop membrane bioreactor (JLMBR)", Journal of Hazardous Materials. Vol. 146(1-2), pp. 399-407.
Abstract: The membrane bioreactor (MBR) used in this study consisted of a jet loop bioreactor (aerobic high rate system) and a membrane separation unit (microfiltration). Jet loop membrane bioreactor (JLMBR) system is a high performance treatment system. High organic loading rates can be achieved with a very small footprint. The JLMBR is a compact biological treatment system which requires much smaller tank volumes than conventional activated sludge system. Solid-liquid separation is performed with a membrane. The JLMBR system, of 35 L capacity, was operated continuously for 3 months with a sludge age of 1. 1-2.8 days and chemical oxygen demand (COD) loads of 3.5-33.5 kg COD m(-3) day(-1). The mean concentration values of COD, total nitrogen (TN) and PO43- in cheese whey (CW) were found as 78,680 mg L-1, 1125 mg L-1 and 378 mg L-1, respectively. Ninety-seven percent COD removal rate was obtained at the sludge age (Theta(c)) of 1.6 days and volumetric loads of 22.2 kg COD m(-3) day(-1). TN removal was obtained as 99% at the loading rates of 17-436 g TN m(-3) day(-1). PO43- removals were between 65 and 88% for the loading of 30-134 g PO43- m(-3) day(-1). The system could simultaneously remove the COD, TN and PO43- at high efficiencies. The sludge flocks were highly motile, dispersed and had poor settling properties. (C) 2006 Elsevier B.V. All rights reserved.
BibTeX:
@article{Farizoglu2007,
  author = {Farizoglu, B. and Keskinler, B. and Yildiz, E. and Nuhoglu, A.},
  title = {Simultaneous removal of C, N, P from cheese whey by jet loop membrane bioreactor (JLMBR)},
  journal = {Journal of Hazardous Materials},
  year = {2007},
  volume = {146},
  number = {1-2},
  pages = {399--407},
  url = {://WOS:000248159700052},
  doi = {10.1016/j.jhazmat.2006.12.051}
}
Farizoglu B and Keskinler B (2007), "Influence of draft tube cross-sectional geometry on K(L)a and epsilon in jet loop bioreactors (JLB)", Chemical Engineering Journal. Vol. 133(1-3), pp. 293-299.
Abstract: Due to their compactness, and high flexibility in operation, the new processes like jet loop bioreactors (JLB) show a large potential for high removal efficiency and significant cost reduction in particular for the biological treatment of highly polluted wastewater. The rate of oxygen delivery determines the efficiency of aerobic processes. A modified JLB with square cross-sectional draft tube was developed in this study. Experiments were performed to investigate the effects of cross-sectional geometry, liquid flow rate and gas flow rate on gas hold-up and KLa. The comparison of these parameters as well as KI.a was carried out for two cross-sectional draft tubes geometry. The results indicated that KI.a values were better by 11-13% in square draft tube. In this study, the mass transfer characteristics with the square draft tube configuration have also been studied and a model was developed for this configuration. (D) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Farizoglu2007a,
  author = {Farizoglu, B. and Keskinler, B.},
  title = {Influence of draft tube cross-sectional geometry on K(L)a and epsilon in jet loop bioreactors (JLB)},
  journal = {Chemical Engineering Journal},
  year = {2007},
  volume = {133},
  number = {1-3},
  pages = {293--299},
  url = {://WOS:000248174600031},
  doi = {10.1016/j.cej.2007.02.022}
}
Kara S, Aydiner C, Demirbas E, Kobya M and Dizge N (2007), "Modeling the effects of adsorbent dose and particle size on the adsorption of reactive textile dyes by fly ash", Desalination. Vol. 212(1-3), pp. 282-293.
Abstract: The adsorption of three reactive dyes, Remazol Red, Rernazol Blue and Rifacion Yellow, from aqueous solutions using fly ash as an adsorbent was studied in an agitated batch system to investigate the influence of two parameters viz., adsorbent dosage and particle size on the removal efficiency of the reactive dyes. Firstly, the adsorbent was characterized with using several methods such as SEM, XRD and FTIR. The FTIR suggested that the dye on fly ash is probably indicating fly ash/dye cornplexation. XRD pattern of fly ash consisted of mainly quartz, mullite with some magnetite and calcite. Surface morphology of fly ash and dye loaded fly ash were obtained with SEM. Secondly, the percentage of dye removal at equilibrium, p, was determined with respect to these two parameters with a constant initial dye concentration of 100 mg/L, agitation speed of 250 rpm, pH 6 and temperature of 22 degrees C for a period of 48 h. The experimental data were treated with two simple empirical models used for predicting the percentage of the dyes adsorbed on the fly ash. Both models showed good correlation coefficients but the best model which determined the p values can be selected on the basis of the standard deviation of the calculated and experimental values.
BibTeX:
@article{Kara2007,
  author = {Kara, S. and Aydiner, C. and Demirbas, E. and Kobya, M. and Dizge, N.},
  title = {Modeling the effects of adsorbent dose and particle size on the adsorption of reactive textile dyes by fly ash},
  journal = {Desalination},
  year = {2007},
  volume = {212},
  number = {1-3},
  pages = {282--293},
  url = {://WOS:000247835500026},
  doi = {10.1016/j.desal.2006.09.022}
}
Karagoz P, Erhan E, Keskinler B and Ozkan M (2007), "Ethanol productivity of Saccharomyces cerevisiae immobilized on polyhype polymer", Febs Journal. Vol. 274, pp. 225-225.
BibTeX:
@article{Karagoz2007,
  author = {Karagoz, P. and Erhan, E. and Keskinler, B. and Ozkan, M.},
  title = {Ethanol productivity of Saccharomyces cerevisiae immobilized on polyhype polymer},
  journal = {Febs Journal},
  year = {2007},
  volume = {274},
  pages = {225--225},
  url = {://WOS:000253283800720}
}
Karagozoglu B, Tasdemir M, Demirbas E and Kobya M (2007), "The adsorption of basic dye (Astrazon Blue FGRL) from aqueous solutions onto sepiolite, fly ash and apricot shell activated carbon: Kinetic and equilibrium studies", Journal of Hazardous Materials. Vol. 147(1-2), pp. 297-306.
Abstract: In this study, sepiolite, fly ash and apricot stone activated carbon (ASAC) were used as adsorbents for the investigation of the adsorption kinetics, isotherms and thermodynamic parameters of the basic dye (Astrazon Blue FGRL) from aqueous solutions at various concentrations (100-300 mg/L), adsorbent doses (3-12 g/L) and temperatures (303-323 K). The result showed that the adsorption capacity of the dye increased with increasing initial dye concentration, adsorbent dose and temperature. Three kinetic models, the pseudo-first-order, second-order, intraparticle diffusion, were used to predict the adsorption rate constants. The kinetics of adsorption of the basic dye followed pseudo-second-order kinetics. Equations were developed using the pseudo-second-order model which predicts the amount of the basic dye adsorbed at any contact time, initial dye concentration and adsorbent dose within the given range accurately. The adsorption equilibrium data obeyed Langmuir isotherm. The adsorption capacities (Q(0)) calculated from the Langmuir isotherm were 181.5 mg/g for ASAC, 155.5 mg/g for sepiolite and 128.2 mg/g for fly ash at 303 K. Thermodynamical parameters were also evaluated for the dye-adsorbent systems and revealed that the adsorption process was endothermic in nature. (C) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Karagozoglu2007,
  author = {Karagozoglu, B. and Tasdemir, M. and Demirbas, E. and Kobya, M.},
  title = {The adsorption of basic dye (Astrazon Blue FGRL) from aqueous solutions onto sepiolite, fly ash and apricot shell activated carbon: Kinetic and equilibrium studies},
  journal = {Journal of Hazardous Materials},
  year = {2007},
  volume = {147},
  number = {1-2},
  pages = {297--306},
  url = {://WOS:000249136200038},
  doi = {10.1016/j.jhazmat.2007.01.003}
}
Kobya M, Bayramoglu M and Eyvaz M (2007), "Techno-economical evaluation of electrocoagulation for the textile wastewater using different electrode connections", Journal of Hazardous Materials. Vol. 148(1-2), pp. 311-318.
Abstract: The bench scale of an electrocoagulation (EC) unit requires a detailed study discerning the effects of continuous variables such as pH, current density and operating time. and type variables such as electrode material and connection mode. This paper presents the results of the treatment of a textile wastewater by EC process. Two electrode materials, aluminum and iron, were connected in three modes namely, monopolar-parallel (MP-P), monopolar-serial (MP-S), and bipolar-serial (BP-S). COD and turbidity removals were selected as performance criteria. For a high COD removal, acidic medium is preferable for both electrode materials. For a high turbidity removal, acidic medium is preferable for aluminum. and neutral medium for iron. High current density is favorable for both removals in the case of iron. In the aluminum case, the current density exhibits a pronounced effect on COD removal, depending strongly on the connection mode, but it has a negligible effect on the turbidity removal. MP-P with iron or MP-S with aluminum electrode are suitable configurations in regard with the overall process performance. Moreover. process economy is as important as removal efficiencies during the process evaluation task. Various direct and indirect cost items including electrical, sacrificial electrodes, labor, sludge handling, maintenance and depreciation costs have been considered in the calculation of the total cost. The results show that MP-P mode is the most cost-effective for both electrode types. Both electrodes show similar results in reducing COD and turbidity, but iron is preferred as a low cost material. Finally, a comparative study showed that EC was faster and more economic; consumed less material and produced less sludge, and pH of the medium was more stabilized than chemical coagulation (CC) for similar COD and turbidity removal levels. For CC, FeCl3 was the preferable salt in view of its techno-economic performance. On the other hand, iron was the preferred electrode material in EC with MP-P system in experimental conditions such as, 30A m(-2) of current density and 15 min of time. the treatment cost was $ 0.245 m(-3). Consequently, the operating cost of CC was 3.2 times as high as the operating cost of EC. (C) 2007 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kobya2007,
  author = {Kobya, M. and Bayramoglu, M. and Eyvaz, M.},
  title = {Techno-economical evaluation of electrocoagulation for the textile wastewater using different electrode connections},
  journal = {Journal of Hazardous Materials},
  year = {2007},
  volume = {148},
  number = {1-2},
  pages = {311--318},
  url = {://WOS:000249312500041},
  doi = {10.1016/j.jhazmat.2007.02.036}
}
Oguz E and Keskinler B (2007), "Comparison among O-3, PAC adsorption, O-3/HCO3-, O-3/H2O2 and O-3/PAC processes for the removal of Bomaplex Red CR-L dye from aqueous solution", Dyes and Pigments. Vol. 74(2), pp. 329-334.
Abstract: Various processes including O-3, powder activated carbon (PAC) adsorption, O-3/HCO3-, O-3/H2O2 and O-3/PAC were used in order to remove dye and chemical oxygen demand (COD) from synthetic wastewater containing Bomaplex Red CR-L dye in a semi-batch reactor. These processes rapidly removed the dye and COD from dye solution. The dye removal efficiency was over 99% for a reaction period of 30 min for all the processes. It was observed that PAC adsorption and O-3/PAC processes were considerably more effective than ozonation process for the removal of COD from dye Solution. The COD removal efficiency of O-3/PAC was higher than PAC adsorption process. O-3/PAC process was considerably effective to remove COD from dye solutions despite using less amount of PAC (approximately four times less than one used for PAC adsorption) for the same amount of COD removal with a higher efficiency. O-3/HCO3- process positively affected the COD removal efficiency, whereas O-3/H2O2 process negatively affected the COD removal efficiency as compared to the ozonation process alone. In addition, the yield and mechanisms of dye removal were also explained on the basis of the results of Fourier transform infrared spectroscopy (FTIR). It was concluded that the O-3/PAC process is a highly efficient process to remove dye and COD from synthetic textile wastewaters as compared to the other processes. (c) 2006 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Oguz2007,
  author = {Oguz, E. and Keskinler, B.},
  title = {Comparison among O-3, PAC adsorption, O-3/HCO3-, O-3/H2O2 and O-3/PAC processes for the removal of Bomaplex Red CR-L dye from aqueous solution},
  journal = {Dyes and Pigments},
  year = {2007},
  volume = {74},
  number = {2},
  pages = {329--334},
  url = {://WOS:000244588000013},
  doi = {10.1016/j.dyepig.2006.02.011}
}
Ozpinar O and Ozkan MB (2007), "Cellulose degradation and glucose accumulation by Clostridium thermocellum ATCC 27405 under different cultural conditions", Annals of Microbiology. Vol. 57(3), pp. 395-400.
Abstract: Effect of various cultural parameters on cellulose degradation, glucose accumulation and ethanol production by Clostridium thermocellum ATCC 27405 were investigated. Optimum pH values for glucose accumulation and ethanol production were determined as 7 and 10, respectively. Highest amount of ethanol (0.92 g/l) was obtained from the culture which contains 10 g urea/l with 34.5% decrease in glucose accumulation. Addition of 100 mM phosphate to the medium increased ethanol production while cellulose degradation and sugar accumulation decreased by 34 and 99%, respectively. Among minerals tested, Mg+2 was found to be the most important element which affects cellulose degradation. When the medium contained no Mg+2, residual cellulose concentration was 4.3 g cellulose/l. When the cultural parameters were optimised, glucose accumulation started at early days of fermentation and glucose concentration was 60% higher than that of the control at the loth day of fermentation.
BibTeX:
@article{Ozpinar2007,
  author = {Ozpinar, O. and Ozkan, M. B.},
  title = {Cellulose degradation and glucose accumulation by Clostridium thermocellum ATCC 27405 under different cultural conditions},
  journal = {Annals of Microbiology},
  year = {2007},
  volume = {57},
  number = {3},
  pages = {395--400},
  url = {://WOS:000250319900016}
}
Sulak MT, Demirbas E and Kobya M (2007), "Removal of Astrazon Yellow 7GL from aqueous solutions by adsorption onto wheat bran", Bioresource Technology. Vol. 98(13), pp. 2590-2598.
Abstract: Adsorption kinetic and equilibrium of a basic dye (Astrazon Yellow 7GL) from aqueous solutions at various initial dye concentration (50-300 mg/l), pH (4-10), adsorbent dosage (2-8 g/l), particle size (354-846 mu m) and temperature (30-50 C) on wheat bran were studied in a batch mode operation. The result showed that the amount adsorbed of the dye increased with increasing initial dye concentration and contact time, whereas particle size and pH had no significant affect on the amount of dye adsorbed by the adsorbent. A comparison of kinetic models on the overall adsorption rate showed that dye/adsorbent system was best described by the pseudo second-order rate model. The removal rate was also dependent on both external mass transfer and intra-particle diffusion. The low value of the intraparticle diffusivity, 10(-11) cm(2)/S, indicated the significant influence of intraparticle diffusion on the kinetic control. The adsorption capacity (Q(0)) calculated from the Langmuir isotherm was 69.06 mg/g for at pH 5.6, 303 K for the particle size of 354 mu m. The experimental data yielded excellent fits with Langmuir and Tempkin isotherm equations. Different thermodynamic parameters showed that the reaction was spontaneous and endothermic in nature. (c) 2006 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Sulak2007,
  author = {Sulak, M. T. and Demirbas, E. and Kobya, M.},
  title = {Removal of Astrazon Yellow 7GL from aqueous solutions by adsorption onto wheat bran},
  journal = {Bioresource Technology},
  year = {2007},
  volume = {98},
  number = {13},
  pages = {2590--2598},
  url = {://WOS:000247382700019},
  doi = {10.1016/j.biortech.2006.09.010}
}
Terzi O, Erhan E, Tan I, Korkut S and Ozkan M (2007), "Cloning, purification and immobilization of thermostable L-lactate dehydrogenase enzyme on polygluteraldehyde-pyrol polymer", Febs Journal. Vol. 274, pp. 305-305.
BibTeX:
@article{Terzi2007,
  author = {Terzi, O. and Erhan, E. and Tan, I. and Korkut, S. and Ozkan, M.},
  title = {Cloning, purification and immobilization of thermostable L-lactate dehydrogenase enzyme on polygluteraldehyde-pyrol polymer},
  journal = {Febs Journal},
  year = {2007},
  volume = {274},
  pages = {305--305},
  url = {://WOS:000253283801038}
}
Turker M and Celen I (2007), "Removal of ammonia as struvite from anaerobic digester effluents and recycling of magnesium and phosphate", Bioresource Technology. Vol. 98(8), pp. 1529-1534.
Abstract: A second order kinetic model was developed to predict the rate and extent of NH4+ removal as struvite from anaerobic digester effluents . Alternative to this, NH4+ can be recovered from struvite and the remaining Mg2+ and PO43- can be recycled back to the wastewater to fix more NH4+. The NH4+ solution was retained and the remaining Mg2+ and PO43- were returned back to be mixed with wastewater. In a five-step process, NH4+ recovery was initially 92% and progressively decreased to 77% in the fifth stage, due to loss of Mg2+ and PO43- at each step in the supernatant. Finally, economic analysis of recycling nutrients was performed and compared to the one step process. The cost of NH4+ recovery was calculated as $0.36/kg NH4-N which is lower than $7.7/kg NH4-N the cost of one step process without considering the market value of struvite obtained in one step process. (c) 2006 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Turker2007,
  author = {Turker, M. and Celen, I.},
  title = {Removal of ammonia as struvite from anaerobic digester effluents and recycling of magnesium and phosphate},
  journal = {Bioresource Technology},
  year = {2007},
  volume = {98},
  number = {8},
  pages = {1529--1534},
  url = {://WOS:000244775100003},
  doi = {10.1016/j.biortech.2006.06.026}
}
Uyar G, Oren M, Yildirim Y and Ince M (2007), "Mosses as indicators of atmospheric heavy metal deposition around a coal-fired power plant in Turkey", Fresenius Environmental Bulletin. Vol. 16(2), pp. 182-192.
Abstract: This study was carried out from May 2003 to October 2004 in the vicinity of Catalagzi coal-fired power plant (CATES) located in Zonguldak, North-West Turkey, in order to investigate atmospheric heavy metal depositions by sampling and analysing Pleurocarp mosses as biomonitoring plants. Initially, ISC-ST (Industrial Source Complex-Short Term) dispersion models were used to determine theoretically the most polluted sites of CATES. After the modelling, sampling was performed in these theoretically determined grids. Samples were analyzed using graphite-furnace atomic absorption spectrometry (AAS) after wet digestion. In the region, the general order of heavy metal content in samples of mosses was determined to be as follows: Fe>Pb>Ni>Cr>Cu>Co>As. Background mean levels of the metals studied, except Cu, were determined and found to be higher than that of European background. The results are also presented in the form of thematic maps using the Geographic Information System (GIS).
BibTeX:
@article{Uyar2007,
  author = {Uyar, G. and Oren, M. and Yildirim, Y. and Ince, M.},
  title = {Mosses as indicators of atmospheric heavy metal deposition around a coal-fired power plant in Turkey},
  journal = {Fresenius Environmental Bulletin},
  year = {2007},
  volume = {16},
  number = {2},
  pages = {182--192},
  url = {://WOS:000244937300012}
}
Uyar G, Oren M and Ince M (2007), "Atmospheric heavy metal deposition in Duzce province by using mosses as biomonitors", Fresenius Environmental Bulletin. Vol. 16(2), pp. 145-153.
Abstract: This research was carried out around the industrialised area and D100 highway in Duzce, in order to determine the atmospheric heavy metal deposition by using mosses as biomonitors. Sampling was performed based on the principle that carpet-forming bryophytes (pleurocarpous mosses) at 14 sites distributed over the study area between 2003 and 2004. Dried samples were digested according to the wet digestion method, and the concentrations of heavy metals were determined by graphite-furnace atomic absorption spectrometry (AAS). According to the results of analyses, the heavy metal concentrations in the region are ordered as follows: Fe>Pb>Cu>Co>Cr>Ni>As. Distribution maps were drawn up by using the Geographic Information System (GIS) for each of the studied metals according to their concentration in the mosses. The results were compared with similar studies in Europe, and. it was observed that the accumulation ratios of iron, lead, arsenic and cobalt are higher than European rates. In addition, significant correlations were found among Fe-Cu and Co between the results, and control sites were compared by using SPSS statistical programme.
BibTeX:
@article{Uyar2007a,
  author = {Uyar, G. and Oren, M. and Ince, M.},
  title = {Atmospheric heavy metal deposition in Duzce province by using mosses as biomonitors},
  journal = {Fresenius Environmental Bulletin},
  year = {2007},
  volume = {16},
  number = {2},
  pages = {145--153},
  url = {://WOS:000244937300007}
}
Yavuz B, Turker M and Engin GO (2007), "Autotrophic removal of sulphide from industrial wastewaters using oxygen and nitrate as electron acceptors", Environmental Engineering Science. Vol. 24(4), pp. 457-470.
Abstract: The effect of environmental conditions on sulphide removal was studied in laboratory-scale batch experiments. Sulphide removal was carried out by adding two different electron acceptors (oxygen and nitrate) and stock sulphide solution to activated sludge solutions obtained from a wastewater treatment plant treating molasses-based industrial wastewaters. The effects of pH, temperature, and concentration of activated sludge on specific sulphide oxidation rates were studied. It was found that 80% sulphide removal was achieved when oxygen was used as an electron acceptor with activated sludge, whereas almost 100% sulphide removal was obtained when nitrate was used. Sulphide removal without activated sludge was also determined. The specific sulphide oxidation rate increased approximately 88% with increasing activated sludge concentration with nitrate as an electron acceptor and sulphide was completely removed within 6 min. When oxygen was used as an electron acceptor, specific removal increased up to 92%; however, it was observed that an amount of sulphide remained in the medium, even though the activated sludge concentration was increased. Additionally, the stoichiometry of sulphide oxidation both with nitrate and oxygen were calculated assuming different end products based on thermodynamic approach and compared with experimental yield values.
BibTeX:
@article{Yavuz2007,
  author = {Yavuz, B. and Turker, M. and Engin, G. O.},
  title = {Autotrophic removal of sulphide from industrial wastewaters using oxygen and nitrate as electron acceptors},
  journal = {Environmental Engineering Science},
  year = {2007},
  volume = {24},
  number = {4},
  pages = {457--470},
  url = {://WOS:000245818000005},
  doi = {10.1089/ees.2006.0068}
}
Yildiz YS, Koparal AS, Irdemez A and Keskinler B (2007), "Electrocoagulation of synthetically prepared waters containing high concentration of NOM using iron cast electrodes", Journal of Hazardous Materials. Vol. 139(2), pp. 373-380.
Abstract: The aim of this investigation is to evaluate the treatibility of synthetically prepared water with high concentration of humic substances by electrocoagulation in batch mode using iron cast electrodes. Effects of applied potential, initial humic substance concentration and supporting electrolyte type on humic substance removal efficiency were investigated. NaNO3, Na2SO4 and NaCl were used as supporting electrolyte. Among these supporting electrolytes, Na2SO4 and NaCl have provided high removal efficiencies, whereas in the experiments using NaNO3 as supporting electrolyte have been observed no flock formation. The highest removal rate is obtainable with NaCl as supporting electrolyte. Removal efficiencies for initial humic substance concentration of 500 mg L-1 with NaCl and Na2SO4 equal to 97.95% for 35 min and 92.69% for 70 min, respectively. This behavior of the system has been derived from oxidation products, available in the bulk solution, of chloride ions. When NaCl is used as supporting electrolyte, there is an advantage of providing the disinfection of water, but humic substances and chloride ions are available in the bulk solution with risk of formation undesirable organo-chlorine compounds, so the Na2SO4 is the most favorable supporting electrolyte. (c) 2006 Elsevier B.V. All rights reserved.
BibTeX:
@article{Yildiz2007,
  author = {Yildiz, Y. S. and Koparal, A. S. and Irdemez, A. and Keskinler, B.},
  title = {Electrocoagulation of synthetically prepared waters containing high concentration of NOM using iron cast electrodes},
  journal = {Journal of Hazardous Materials},
  year = {2007},
  volume = {139},
  number = {2},
  pages = {373--380},
  url = {://WOS:000243822200026},
  doi = {10.1016/j.jhazmat.2006.06.044}
}
Aydiner C, Bayramoglu M, Kara S, Keskinler B and Ince O (2006), "Nickel removal from waters using surfactant-enhanced hybrid PAC/MF process. I. The influence of system-component variables", Industrial & Engineering Chemistry Research. Vol. 45(11), pp. 3926-3933.
Abstract: This study takes aim at exploring the effectiveness of a surfactant-added powdered activated carbon/ microfiltration (PAC/MF) hybrid process in the removal of nickel ions from water and wastewater as a promising technology. For this aim, the influence of system-component variables related to membrane material and pore size, and adsorbent and surfactant types was investigated. Nickel rejection (R-M), surfactant rejection (R-S), and steady-state flux (J*) were taken into account for more elaborately assessing the technical performance of the process. It was determined that the use of a surfactant in this process is justified only above the critical micellar concentration (CMC). Despite the increasing of nickel rejection with the addition of surfactant into the hybrid membrane process, a considerable decrease in steady-state flux is a major drawback of process. The flux decline observed was strongly dependent on surfactant type. This was interpreted as being due to a secondary membrane layer formed by surfactant micelles on the surface and within the membrane pores. The flux decline could also be related to PAC layer formation. Membrane, adsorbent, and surfactant types seem to have the highest relative influence on R-M, R-S, and J*, respectively. As a conclusion, surfactant type and membrane pore size were established as having the biggest and the smallest total influence on process performance, respectively.
BibTeX:
@article{Aydiner2006,
  author = {Aydiner, C. and Bayramoglu, M. and Kara, S. and Keskinler, B. and Ince, O.},
  title = {Nickel removal from waters using surfactant-enhanced hybrid PAC/MF process. I. The influence of system-component variables},
  journal = {Industrial & Engineering Chemistry Research},
  year = {2006},
  volume = {45},
  number = {11},
  pages = {3926--3933},
  url = {://WOS:000237625400019},
  doi = {10.1021/ie051237c}
}
Basar CA, Aydiner C, Kara S and Keskinler B (2006), "Removal of CrO4 anions from waters using surfactant enhanced hybrid PAC/MF process", Separation and Purification Technology. Vol. 48(3), pp. 270-280.
Abstract: The removal of CrO42- anions from aqueous solution using surfactant added hybrid powdered activated carbon (PAC) and crossflow microfiltration (CFMF) process was performed. Experimental runs were studied at various amounts of cetyl trimethyl ammonium bromide (CTAB) as cationic surfactant, PAC as adsorbent and CrO42- ions in feed solution. CFMF unit was operated at constant values of the transmembrane pressure (150 kPa), crossflow velocity (1.18 m/s) and temperature (30 degrees C). Hybrid PAC/MF process performance was investigated in terms of CTAB and CrO42- rejections and, the flux decline. It was shown that the flux declined with time and the rejections varied for various properties of feed solution. CTAB and CrO42- rejections could be achieved as 91 and 97.2% at the conditions of 0.5 g PAC/L, 5 mM CTAB, 0.2 mM CrO42- and 120-min process time. It was found that over the critic micelle concentration (CMC), both CTAB and CrO42- rejections were in the higher values according to the values under the CMC. In addition, membrane blocking mechanisms were investigated to clarify the cake formation mechanism due to PAC. For all experimental conditions, the best results of blocking models obtained for cake filtration, intermediate blocking and standard pore blocking, respectively. It was understood that these blocking mechanisms occurred simultaneously on membrane surface in terms of high r(2) values. A cake layer formed on membrane surface (cake filtration). Pore entrance blocked partially due to particles bridging over pore opening (intermediate blocking). Free CTAB aggregates with or without CrO42- anions, entered into the membrane pores, caused to a layer formation by adsorption and entrapment on the membrane's pore walls (standard pore blocking). Besides, cake resistance (R-c), specific cake resistance (alpha), modified fouling index (MFI) and total dried solid mass of cake per unit membrane area (omega) were also determined to comprehend the reasons of clogging within the membrane and on the surface due to both CTAB aggregates and PAC, respectively. Membrane fouling (MFI) increased with the increasing of PAC, CTAB and CrO42- amounts in feed solution. As a result, flux, rejections and fouling in membrane were shown as a dynamic function of PAC, CTAB and CrO42- as the properties of the feed solution. (c) 2005 Elsevier B.V. All rights reserved.
BibTeX:
@article{Basar2006,
  author = {Basar, C. A. and Aydiner, C. and Kara, S. and Keskinler, B.},
  title = {Removal of CrO4 anions from waters using surfactant enhanced hybrid PAC/MF process},
  journal = {Separation and Purification Technology},
  year = {2006},
  volume = {48},
  number = {3},
  pages = {270--280},
  url = {://WOS:000236526800008},
  doi = {10.1016/j.seppur.2005.07.033}
}
Bayramoglua M, Kobya M, Eyvaz M and Senturk E (2006), "Technical and economic analysis of electrocoagulation for the treatment of poultry slaughterhouse wastewater", Separation and Purification Technology. Vol. 51(3), pp. 404-408.
Abstract: Electrocoagulation (EC) is assessed by a preliminary technical and economic analysis for the treatment of poultry slaughterhouse wastewater (PSW). Chemical oxygen demand (COD) and oil-grease removal efficiencies, and total operating cost have been used for analysis purpose. Various direct and indirect cost items including electrical, sacrificial electrodes, labor, sludge handling, maintenance and depreciation costs have been considered in the calculation of the total cost. Iron and aluminum have been tested as sacrificial electrode material. Initial pH, current density and operating time were investigated as process variables. The experiments demonstrated the effectiveness of EC for the treatment of PSW. Aluminum electrode performed better in reducing the COD, with a removal efficiency as 93% in 25 at low initial pH, such as 3, and current density of 150 A/m(2). On the other hand, iron electrode was more successful in removing oil-grease with 98% efficiency, irrespective of the initial pH. From economic point of view, iron electrode is clearly preferable; the total operating cost is between 0.3 and 0.4$/m(3), which is nearly half that of aluminum electrode. The total operating costs may also been calculated on the basis of $/kg COD removed, which are 0.015 and 0.027 for iron and aluminum electrodes, respectively. (c) 2006 Elsevier B.V. All rights reserved.
BibTeX:
@article{Bayramoglua2006,
  author = {Bayramoglua, M. and Kobya, M. and Eyvaz, M. and Senturk, E.},
  title = {Technical and economic analysis of electrocoagulation for the treatment of poultry slaughterhouse wastewater},
  journal = {Separation and Purification Technology},
  year = {2006},
  volume = {51},
  number = {3},
  pages = {404--408},
  url = {://WOS:000241652500023},
  doi = {10.1016/j.seppur.2006.03.003}
}
Can OT, Kobya M, Demirbas E and Bayramoglu M (2006), "Treatment of the textile wastewater by combined electrocoagulation", Chemosphere. Vol. 62(2), pp. 181-187.
Abstract: Electrocoagulation (EC) due to some advantages over chemical coagulation is becoming a popular process to be used for wastewater treatment. The aim of this paper is to investigate the effect of initial addition of a chemical coagulant such as polyaluminum chloride (PAC) or alum on the COD removal efficiency of EC treatment of textile wastewaters. The two salts exhibited the same performance in chemical coagulation, but in the combined electrocoagulation (CEC), PAC was found to significantly enhance the COD removal rate and efficiency, depending on the amount of the total aluminum supplied, by initial addition and electrochemical generation. A comparative operating cost analysis was also given and it was found that with the same operating cost per mass of COD removed, CEC performance was 80%, in contrast to 23% with EC, in 5 min of operation. (c) 2005 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Can2006,
  author = {Can, O. T. and Kobya, M. and Demirbas, E. and Bayramoglu, M.},
  title = {Treatment of the textile wastewater by combined electrocoagulation},
  journal = {Chemosphere},
  year = {2006},
  volume = {62},
  number = {2},
  pages = {181--187},
  url = {://WOS:000234279500002},
  doi = {10.1016/j.chemosphere.2005.05.022}
}
Dogan O and Kobya M (2006), "Elemental analysis of trace elements in fly ash sample of Yatagan thermal power plants using EDXRF", Journal of Quantitative Spectroscopy & Radiative Transfer. Vol. 101(1), pp. 146-150.
Abstract: Fly ash samples collected by means of an electrostatic precipitator from the lignite-fired Yatagan Power Plants of the located in Turkey was analysed using X-ray fluorescence technique. Five trace elements, namely Nd, Ba, Sr, Mo and As were quantified using XRF. These concentration values can be helpful in developing a environmental pollution abatement approach for various applications of fly ash such as cement manufacture, wastewater treatment, lightweight contraction aggregate, ceramic production, and secondary source in recovery of valuable elements. Present results compared with results of the Kemerkoy thermal power plants [Sahin Y, Karabulut A, Budak G. A practical method for the analysis of overlepped peaks in energy dispersive X-ray spectra. Appl Spectrose Rev 1996;31:333-45]. (C) 2005 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Dogan2006,
  author = {Dogan, O. and Kobya, M.},
  title = {Elemental analysis of trace elements in fly ash sample of Yatagan thermal power plants using EDXRF},
  journal = {Journal of Quantitative Spectroscopy & Radiative Transfer},
  year = {2006},
  volume = {101},
  number = {1},
  pages = {146--150},
  url = {://WOS:000238203000013},
  doi = {10.1016/j.jqsrt.2005.11.072}
}
Engin GO and Demir I (2006), "Cost analysis of alternative methods for wastewater handling in small communities", Journal of Environmental Management. Vol. 79(4), pp. 357-363.
Abstract: Wastewater collection and treatment is quite important for sustainable management. It would be uneconomical and impractical to provide sewer systems and separate wastewater treatment plants (WWTP) for small communities. The decision process in wastewater planning is rather important in terms of comparing the alternatives considered. The two important points in the management of wastewater at rural areas not connected to a sewer system are to develop an optimized operation strategy and to make sure that the complete system is environmentally and economically sustainable. In some regions, package treatment could be an alternative solution. However, in cases where there is an existing large WWTP, a cluster system, where sewage generated by small communities could be transported via conveyors to a centralized WWTP, could be employed. In this study, the wastewater treatment and disposal problems in small communities were addressed and an alternative wastewater handling scenario was proposed. Additionally, three wastewater handling scenarios were compared. As a case study, Gebze villages were selected. (c) 2005 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Engin2006,
  author = {Engin, G. O. and Demir, I.},
  title = {Cost analysis of alternative methods for wastewater handling in small communities},
  journal = {Journal of Environmental Management},
  year = {2006},
  volume = {79},
  number = {4},
  pages = {357--363},
  url = {://WOS:000238316500004},
  doi = {10.1016/j.jenvman.2005.07.011}
}
Farizoglu B and Keskinler B (2006), "Sludge characteristics and effect of crossflow membrane filtration on membrane fouling in a jet loop membrane bioreactor (JLMBR)", Journal of Membrane Science. Vol. 279(1-2), pp. 578-587.
Abstract: An aerobic jet loop membrane bioreactor (JLMBR) activated sludge process of 35 L working volume was used to investigate its applicability in industrial wastewaters, specifically cheese whey wastewater. A loading rate of 22.2 kg COD/(m(3) day) and 1.6 days of sludge age was achieved with 97% COD removal efficiency. During the study, the activated sludge was found non-settable and slimy characteristic and non-flocculating motile bacteria structure. Therefore, it was been conducted that the membrane separation was indispensable to obtain high performance from jet loop bioreactor (JLB). From the investigation of crossflow microfiltration characteristic of the system, it was found that the fluxes decreased and MFI increased with increasing MLSS concentration. The increasing crossflow velocity greatly reduced the cake formation on the membrane surface and increased the steady state permeate fluxes, decreasing specific cake resistance (alpha) values. The cake layer was in a highly compressible form. The compressibility coefficient was calculated as 0.98. In addition to this, the pseudo gel concentration (C-G) on the membrane surface was calculated to be 73,130 mg/L. For the investigation of the membrane filtration mechanism, it was found that the fouling mechanism showed high compatibility with complete pore blocking model and particularly cake filtration model (R-2 = 0.99). (c) 2006 Elsevier B.V. All rights reserved.
BibTeX:
@article{Farizoglu2006,
  author = {Farizoglu, B. and Keskinler, B.},
  title = {Sludge characteristics and effect of crossflow membrane filtration on membrane fouling in a jet loop membrane bioreactor (JLMBR)},
  journal = {Journal of Membrane Science},
  year = {2006},
  volume = {279},
  number = {1-2},
  pages = {578--587},
  url = {://WOS:000238505900063},
  doi = {10.1016/j.memsci.2005.12.050}
}
Gokdogan O, Sulak M and Gulce H (2006), "Investigation of oxygen electroreduction on polyvinylferrocene coated glassy carbon electrodes", Chemical Engineering Journal. Vol. 116(1), pp. 39-45.
Abstract: The electroreduction of O-2 has been investigated at a bare glassy carbon (GC) electrode and a polyvinylferrocene (PVF) coated glassy carbon electrode (PVF-GC) in both 0.1 M NaClO4 Solution and phosphate buffer solutions of various pH values by using cyclic voltammetry and chronoamperometry. Two well-defined reduction peaks were observed at about -0.55 and -0.80 V versus SCE at PVF-GC electrode while one reduction peak was observed at about -0.85 V versus SCE at GC electrode in 0.1 M NaClO4 solution and phosphate buffer solutions of pH > 6. Two peaks at PVF-GC electrode indicated a two-step four-electron pathway of O-2 in these mediums. The first peak was ascribable to the two-electron reduction of O-2 to H2O2, while the second peak was assigned to the reduction of H2O2 to H2O. The electrocatalytic effects of PVF matrix for the reduction O-2 and the reduction of H2O2 were observed. The effects of the film thickness, O-2 concentration, pH and potential scan rates were investigated. (c) 2005 Elsevier B.V. All rights reserved.
BibTeX:
@article{Gokdogan2006,
  author = {Gokdogan, O. and Sulak, M. and Gulce, H.},
  title = {Investigation of oxygen electroreduction on polyvinylferrocene coated glassy carbon electrodes},
  journal = {Chemical Engineering Journal},
  year = {2006},
  volume = {116},
  number = {1},
  pages = {39--45},
  url = {://WOS:000234675700005},
  doi = {10.1016/j.cej.2005.10.016}
}
Karagunduz A and Unal D (2006), "New method for evaluation of heavy metal binding to alginate beads using pH and conductivity data", Adsorption-Journal of the International Adsorption Society. Vol. 12(3), pp. 175-184.
Abstract: Extensive research has been conducted for removal and recovery of heavy metals from wastewater and industrial wastewater in recent years. Due to its low cost and high sorption efficiency, alginate was extensively investigated as a biosorbent. It is known that the sorption of metals to alginate is rate limited. However, the sampling in the beginning of experiments, from 30 seconds to few minutes, is very difficult, if not impossible. In this study, a nontraditional experimental method was used to determine the removal kinetics of metals for short time periods. A relationship among pH, conductivity, and metal concentration was established. It was shown that the sorption mechanism was ion exchange for all metals investigated in this study. A series of experiments was conducted to determine the ion exchange kinetics of different metals at varying pH conditions. Second order pseudo rate kinetics was shown to define the experimental findings well. Results also showed that the extent of exchange significantly reduced as the pH decreased. The selectivity of metal exchange to alginate beads was determined. It was observed that the extent of the ion exchange was greatest for CCu2+ and lowest for Mn2+ and Fe2+, following the order of Cu2+ > Zn2+ congruent to Co2+ congruent to Ni2+ > Mn2+ congruent to Fe2+.
BibTeX:
@article{Karagunduz2006,
  author = {Karagunduz, A. and Unal, D.},
  title = {New method for evaluation of heavy metal binding to alginate beads using pH and conductivity data},
  journal = {Adsorption-Journal of the International Adsorption Society},
  year = {2006},
  volume = {12},
  number = {3},
  pages = {175--184},
  url = {://WOS:000242496000002},
  doi = {10.1007/s10450-006-0144-1}
}
Karagunduz A, Kaya Y, Keskinler B and Once S (2006), "Influence of surfactant entrapment to dried alginate beads on sorption and removal of Cu2+ ions", Journal of Hazardous Materials. Vol. 131(1-3), pp. 79-83.
Abstract: The removal of heavy metals has been investigated widely in recent years due to their potential health risk to human beings. In this study, the removals of copper from aqueous phase by alginate and SDBS entrapped alginate was investigated. First, a series of equilibrium sorption experiments were conducted at different initial pH values. Both equilibrium copper concentration and final pH values were observed. Then, a series of kinetic experiments were conducted and a second order rate relationship was fit to the experimental data. Equilibrium sorption experiments showed that the sorption of CU2+ ions by 2% of SDBS entrapped alginate beads were greater than the plain and 0.5% of SDBS entrapped alginate beads. More H+ ion exchange occurred with the 2% of SDBS entrapped alginate beads, which was attributed to the increased number of the exchange sites on the alginate due to the sorption of surfactant to the beads. Kinetic sorption experiments showed that the equilibrium was reached faster for 2% of SDBS entrapped alginate beads. Results were successfully represented using second order kinetic model. Both equilibrium and kinetic experiments showed that the sorption of CU2+ ions increased as the pH of the aqueous solution increased. (c) 2005 Elsevier B.V. All rights reserved.
BibTeX:
@article{Karagunduz2006a,
  author = {Karagunduz, A. and Kaya, Y. and Keskinler, B. and Once, S.},
  title = {Influence of surfactant entrapment to dried alginate beads on sorption and removal of Cu2+ ions},
  journal = {Journal of Hazardous Materials},
  year = {2006},
  volume = {131},
  number = {1-3},
  pages = {79--83},
  url = {://WOS:000236930100011},
  doi = {10.1016/j.jhazmat.2005.09.020}
}
Kaya Y, Aydiner C, Barlas H and Keskinler B (2006), "Nanofiltration of single and mixture solutions containing anionics and nonionic surfactants below their critical micelle concentrations (CMCs)", Journal of Membrane Science. Vol. 282(1-2), pp. 401-412.
Abstract: Nanofiltration (NF) of linear alkyl benzene sulfonate (LABS), sodium dodecylether sulfate (SLES) as anionic surfactants and of nonylphenol ethoxylate (NPE) as nonionic surfactant for selected concentrations below CMC (critical micelle concentration) was carried out using various membranes as NF PES10, N 30F and XN 45. Membrane fouling was observed in the order of XN 45 > NF PES10 > N 30F for LABS, SLES and mixture solutions, while the order was as NF PES 10 > N 30F > XN 45 for NPE solution. The most fouled membrane, XN 45, exhibited the least fouling on the surface in opposition to N 30F. In single solutions, the highest rejection of LABS and SLES was obtained around 97-98% by NF PES 10 and N 30F, whereas when XN 45 was used, the rejection rate was around 93%. In mixture solution, the rejection rates were observed to be around 97 and 98% by NF PES 10 and N 30F, respectively, which were quite different from XN 45 rejection rates. The enhancement of rejections compared to the adsorption of single surfactants, except for NPE-XN 45 couple, could have been taken place by synergism between nonionic and anionics as a function of both stronger interactions between surfactants and surface and, more effective physical separation forces based on micellation. In NPE-XN 45 couple, NPE was rejected predominantly under the effect of binding LABS, which had the highest feed concentration in mixture, on the membrane surface. Consequently, it was determined that, XN 45 for nonionic (NPE) and NF PES10 for anionics (LABS and SLES) and mixture solution (LABS + SLES + NPE) performed the best performance in NF of single and mixture surfactant solutions. (c) 2006 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kaya2006,
  author = {Kaya, Y. and Aydiner, C. and Barlas, H. and Keskinler, B.},
  title = {Nanofiltration of single and mixture solutions containing anionics and nonionic surfactants below their critical micelle concentrations (CMCs)},
  journal = {Journal of Membrane Science},
  year = {2006},
  volume = {282},
  number = {1-2},
  pages = {401--412},
  url = {://WOS:000240579700045},
  doi = {10.1016/j.memsci.2006.05.047}
}
Kazanci N, Toprak O, Leroy SAG, Oncel S, Ileri O, Emre O, Costa P, Erturac K and McGee E (2006), "Boron content of Lake Ulubat sediment: A key to interpret the morphological history of NW Anatolia, Turkey", Applied Geochemistry. Vol. 21(1), pp. 134-151.
Abstract: Freshwater Lake Ulubat (c. 1.5 m deep and c. 138 km(2)) receives sediment from a 10.414 km(2) area in the seismically active Susurluk Drainage Basin (SDB) of NW Turkey. The B and trace element contents of the lake infill seem to be a link between the fresh landforms of the SDB and the lacustrine sediment. Deposition in Lake Ulubat has been 1.60 cm a(-1) for the last 50 a according to radionucleides; however the sedimentation rate over the last millennium was 0.37 cm a(-1) based on 14 C dating. The B content of the lacustrine infill displays a slight increase at 0.50 m and a drastic increase at 4 m depth occurring c. 31 a and c. 1070 a ago, respectively. Probably the topmost change corresponds to the start of open mining in the SDB and the second one to the natural trenching of borate ore-deposits. These dates also show indirectly a 1.4 cm a(-1) erosion rate during the last millennium as the borate beds were trenched up to 15 m. By extrapolation, it is possible to establish that the formation of some of the present morphological features of the southern Marmara region, especially river incision, began in the late Pleistocene, and developed especially over the last 75 ka. (c) 2005 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Kazanci2006,
  author = {Kazanci, N. and Toprak, O. and Leroy, S. A. G. and Oncel, S. and Ileri, O. and Emre, O. and Costa, P. and Erturac, K. and McGee, E.},
  title = {Boron content of Lake Ulubat sediment: A key to interpret the morphological history of NW Anatolia, Turkey},
  journal = {Applied Geochemistry},
  year = {2006},
  volume = {21},
  number = {1},
  pages = {134--151},
  url = {://WOS:000235108700009},
  doi = {10.1016/j.apgeochem.2005.09.003}
}
Kobya M, Senturk E and Bayramoglu M (2006), "Treatment of poultry slaughterhouse wastewaters by electrocoagulation", Journal of Hazardous Materials. Vol. 133(1-3), pp. 172-176.
Abstract: Treatment of poultry slaughterhouse wastewater (PSW) by electrocoagulation (EC) has been investigated batchwise in this paper. Effects of the process variables such as medium pH, electrode material, current density, and operating time are investigated on chemical oxygen demand (COD) and oil-grease removal efficiencies, electrical energy consumption, and sacrificial electrode consumption. The highest COD removal efficiency is reached with aluminum as 93%, and maximum oil-grease removal is obtained with iron electrodes as 98%. Combined use of both electrode materials in the EC unit may yield high process performances with respect to both COD and oil-grease removals. Further work needs to be carried out at pilot scale to assess the technical end economic feasibility of the process. (c) 2005 Elsevier B.V All rights reserved.
BibTeX:
@article{Kobya2006,
  author = {Kobya, M. and Senturk, E. and Bayramoglu, M.},
  title = {Treatment of poultry slaughterhouse wastewaters by electrocoagulation},
  journal = {Journal of Hazardous Materials},
  year = {2006},
  volume = {133},
  number = {1-3},
  pages = {172--176},
  url = {://WOS:000237825000024},
  doi = {10.1016/j.jhazmat.2005.10.007}
}
Kobya M, Hiz H, Senturk E, Aydiner C and Demirbas E (2006), "Treatment of potato chips manufacturing wastewater by electrocoagulation", Desalination. Vol. 190(1-3), pp. 201-211.
Abstract: Treatment of wastewater from potato chips manufacturing by electrocoagulation (EC) was investigated. Experiments were conducted to determine the optimum operating conditions such as electrode type, pH, current density and retention time. Aluminium and iron electrodes were used, and aluminium electrodes were found to be more suitable since it had a higher removal rate of COD, turbidity and suspended solids than the iron electrode. The removal efficiencies of COD and turbidity were high, being 60% and 98%, respectively, with retention time < 40 min. 0.05-1.75 kg (per kg COD removed) of dried sludge was removed. COD removal kinetics during EC process was described by a macro-kinetics model. Results from the kinetic studies showed that the kinetic data fit the second-order kinetic model well. The operating costs investigated in the present study were the energy cost of EC and the material cost due to the consumption of aluminium electrode. Operating costs were varied in the range of 0.48 to 5.42 $/m(3) and 0.62 to 6.32 $/m(3) wastewater treated at 20-300 A/m(2) and 5-40 min, respectively. The energy consumption was 4 kWh/m(3) for wastewater treated less than 8 min under typical operating conditions.
BibTeX:
@article{Kobya2006a,
  author = {Kobya, M. and Hiz, H. and Senturk, E. and Aydiner, C. and Demirbas, E.},
  title = {Treatment of potato chips manufacturing wastewater by electrocoagulation},
  journal = {Desalination},
  year = {2006},
  volume = {190},
  number = {1-3},
  pages = {201--211},
  url = {://WOS:000237169800019},
  doi = {10.1016/j.desal.2005.10.006}
}
Kobya M, Demirbas E, Yesilot S and Baskaya R (2006), "Adsorption kinetics for the removal of nitrite ions from aqueous solutions by an ion-exchange resin", Adsorption Science & Technology. Vol. 24(2), pp. 131-141.
Abstract: The adsorption kinetics of nitrite ions in aqueous solutions onto an anion-exchange resin A-250 was explored in a well-stirred tank. The capacity of the ion-exchange resin for the removal of nitrite ions from aqueous solution was investigated under different conditions, viz. initial concentration (10-50 mg/l), pH (2-8), particle size (565-850 mu m) and resin dosage (2-8 g/l). A number of kinetic models such as those of external and intraparticle diffusion were applied to the results from this study in order to identify the adsorption mechanism. The results correlated well with the intraparticle diffusion model. The experimental parameters had an effect on the effective pore and surface diffusivities. Adsorption of nitrite ions onto the resin showed that the latter could be used as an efficient adsorbent material for the removal of nitrite ions from aqueous solutions.
BibTeX:
@article{Kobya2006b,
  author = {Kobya, M. and Demirbas, E. and Yesilot, S. and Baskaya, R.},
  title = {Adsorption kinetics for the removal of nitrite ions from aqueous solutions by an ion-exchange resin},
  journal = {Adsorption Science & Technology},
  year = {2006},
  volume = {24},
  number = {2},
  pages = {131--141},
  url = {://WOS:000240376900003},
  doi = {10.1260/026361706778529182}
}
Kobya M, Demirbas E, Can OT and Bayramoglu M (2006), "Treatment of levafix orange textile dye solution by electrocoagulation", Journal of Hazardous Materials. Vol. 132(2-3), pp. 183-188.
Abstract: The decolorization of the levafix orange textile dye in aqueous solution by electrocoagulation using aluminum sacrificial anode has been investigated. The process performance is analyzed in terms of decolorization efficiency and the important cost-related parameters such as electrode and energy consumptions, as a function of initial pH, conductivity, current density, initial dye concentration and electrolysis time. The present study proves the effectiveness of electrochemical treatment for the textile dye solution. 95% decolorization efficiency may be obtained at suitable operating conditions such as; current density 100 A/m(2), operating time 12 min and initial pH 6.4. The corresponding electrode and energy consumptions during the electrolysis were found to be 1.8 kg Al/kg dye and 35 kWh/kg dye. (c) 2005 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kobya2006c,
  author = {Kobya, M. and Demirbas, E. and Can, O. T. and Bayramoglu, M.},
  title = {Treatment of levafix orange textile dye solution by electrocoagulation},
  journal = {Journal of Hazardous Materials},
  year = {2006},
  volume = {132},
  number = {2-3},
  pages = {183--188},
  url = {://WOS:000237612100008},
  doi = {10.1016/j.jhazmat.2005.07.084}
}
Oguz E, Keskinler B, Celik C and Celik Z (2006), "Determination of the optimum conditions in the removal of Bomaplex Red CR-L dye from the textile wastewater using O-3, H2O2, HCO3- and PAC", Journal of Hazardous Materials. Vol. 131(1-3), pp. 66-72.
Abstract: Bomaplex Red CR-L textile dye was used in the experimental studies. Taguchi method was applied to determine optimum conditions in the removal of dye from synthetic textile wastewater. After the parameters were determined to remove Bomaplex Red CR-L dye from synthetic textile wastewater, the experimental studies were realized. The chosen experimental parameters and their ranges: HCO3- (mM), 0-39; temperature (degrees C), 18-70; ozone-air flow rate (1min(-1)), 5-15; the dye concentration (ppm), 200-600; particulate activated carbon (PAC) (g), 0-1.5; H2O2 (MM), 0-0056; pH, 3-12; and treatment time (min), 10-30, respectively. An orthogonal array L-18 (2(1) x 3 7) for experimental plan and the smaller the better performance statistics formula were selected to define optimum conditions. The optimum conditions were found to be as follows: HCO3-(mM), 0; temperature (degrees C), 70; ozone-air flow rate (1 min(-1)), 10; the dye concentration (ppm), 200; particulate activated carbon (PAC) (g), 1; H2O2,(mM), 0.056; pH, 12; and time (min), 20. Under these optimum conditions, it was determined that the Bomaplex Red CR-L removal efficiency from textile wastewater was 99%. (c) 2005 Elsevier B.V. All rights reserved.
BibTeX:
@article{Oguz2006,
  author = {Oguz, E. and Keskinler, B. and Celik, C. and Celik, Z.},
  title = {Determination of the optimum conditions in the removal of Bomaplex Red CR-L dye from the textile wastewater using O-3, H2O2, HCO3- and PAC},
  journal = {Journal of Hazardous Materials},
  year = {2006},
  volume = {131},
  number = {1-3},
  pages = {66--72},
  url = {://WOS:000236930100009},
  doi = {10.1016/j.jhazmat.2005.09.15}
}
Sulak MT, Gokdogan O, Gulce A and Gulce H (2006), "Amperometric glucose biosensor based on gold-deposited polyvinylferrocene film on Pt electrode", Biosensors & Bioelectronics. Vol. 21(9), pp. 1719-1726.
Abstract: The preparations and performances of the novel amperometric biosensors for glucose based on immobilized glucose oxidase (GOD) on modified Pt electrodes are described. Two types of modified electrodes for the enzyme immobilization were used in this study, polyvinyl ferrocene (PVF) coated Pt electrode and gold deposited PVF coated Pt electrode. A simple method forthe immobilization of GOD enzyme on the modified electrodes was described. The enzyme electrodes developed in this study were called as PVF-GOD enzyme electrode and PVF-Au-GOD enzyme electrode, respectively. The amperometric responses of the enzyme electrodes were measured at constant potential, which was due to the electrooxidation of enzymatically produced H2O2. The electrocatalytic effects of the polymer. PVF. and the cold particles towards the electrooxidation of the enzymatically generated H2O2 offers sensitive and selective monitoring of glucose. The biosensor based on PVF-Au-GOD electrode has 6.6 times larger maximum current, 3.8 times higher sensitivity and 1.6 times larger linear working portion than those of the biosensor based on PVF-GOD electrode. The effects of the applied potential. the thickness of the polymeric film. the amount of the immobilized enzyme, pH. the amount of the deposited An, temperature and substrate concentration on the responses of the biosensors were investigated. The optimum pH was found to be pH 7.4 at 25 degrees C. Finally the effects of interferents, stability of the biosensors and applicability to serum analysis of the biosensor were also investigated. (c) 2005 Elsevier B.V. All rights reserved.
BibTeX:
@article{Sulak2006,
  author = {Sulak, M. T. and Gokdogan, O. and Gulce, A. and Gulce, H.},
  title = {Amperometric glucose biosensor based on gold-deposited polyvinylferrocene film on Pt electrode},
  journal = {Biosensors & Bioelectronics},
  year = {2006},
  volume = {21},
  number = {9},
  pages = {1719--1726},
  url = {://WOS:000236317400006},
  doi = {10.1016/j.bios.2005.08.008}
}
Akyol A and Bayramoglu M (2005), "Photocatalytic degradation of Remazol Red F3B using ZnO catalyst", Journal of Hazardous Materials. Vol. 124(1-3), pp. 241-246.
Abstract: The photocatalytic degradation of aqueous solution of a commercial azo-reactive textile dye, Remazol Red F3B, has been investigated in a batch slurry reactor, in the presence of ZnO catalyst using two different UV light sources emitting at 254 nm and 365 nm. The effects of various process variables on degradation performance of the process have been investigated. The results showed that decolourization and total organic carbon (TOC) removal are both affected in the same manner by the solution pH in the pH range 6-10, showing maxima at pH 7 and pH 10. They are inversely related to the dye concentration, they increase in power-law with the light intensity. Decolourization is faster with 365 nm UV. TOC removal is not affected by UV wavelength in the initial period up to 20 min, after which it progresses faster under 365 nm UV radiation. These results indicate that the UV wavelength influences especially the degradation rate of the intermediate products generated during the initial period of the photocatalytic process. Finally, catalyst loading affects both efficiencies in the same trend, which are maximized at about 2 g/l catalyst loading. (c) 2005 Elsevier B.V. All rights reserved.
BibTeX:
@article{Akyol2005,
  author = {Akyol, A. and Bayramoglu, M.},
  title = {Photocatalytic degradation of Remazol Red F3B using ZnO catalyst},
  journal = {Journal of Hazardous Materials},
  year = {2005},
  volume = {124},
  number = {1-3},
  pages = {241--246},
  url = {://WOS:000231403600032},
  doi = {10.1016/j.hazmat.2005.05.006}
}
Assa P, Ozkan M and Ozcengiz G (2005), "Thermostability and regulation of Clostridium thermocellum L-lactate dehydrogenase expressed in Escherichia coli", Annals of Microbiology. Vol. 55(3), pp. 193-197.
Abstract: In this study, L-lactate dehydrogenase (L-LDH) of Clostridium thermocellum previously cloned aid expressed in Escherichia coli FMJ39 was partially purified and characterised. Optimum temperature and pH of the enzyme were found as 50 degrees C and 7.5, respectively. Different concentrations of Mn2+ did not affect the enzyme activity. Addition of 20-30 mM Mg2+, or the other hand, increased the LDH activity by about 10%. Relatively high concentrations of NaCl (2 M), fructose-1,6-diphosphate (FDP, 5 mM), ATP (10 mM) and NAD (40 mM) decreased LDH activity by 36, 25, 40 and 100%, respectively. Oxamate and oxalate inhibited LDH activity by 41 and 28%, respectively, when each was added at a concentration of 0.5 mM. When compared to its non-thermotolerant counterparts, the enzyme was found to be very stable when incubated at room temperature, 4 degrees C and even at 50 degrees C.
BibTeX:
@article{Assa2005,
  author = {Assa, P. and Ozkan, M. and Ozcengiz, G.},
  title = {Thermostability and regulation of Clostridium thermocellum L-lactate dehydrogenase expressed in Escherichia coli},
  journal = {Annals of Microbiology},
  year = {2005},
  volume = {55},
  number = {3},
  pages = {193--197},
  url = {://WOS:000232444500006}
}
Aydiner C, Kobya M and Demirbas E (2005), "Cyanide ions transport from aqueous solutions by using quaternary ammonium salts through bulk liquid membranes", Desalination. Vol. 180(1-3), pp. 139-150.
Abstract: Extraction experiments were carried out to determine the suitable solvent and carrier type. Five different solvents and carriers were used and verified. Trichloromethane and tetraoctyl ammonium chlorides were found to be the most appropriate solvent and carrier type for this study. The coupled transport of cyanide ions in aqueous solutions through bulk liquid membrane (BLM) was investigated using various stirring speeds and temperatures. Cyanide ion transport through BLM technique was analyzed according to coupled non-steady state kinetics of two consecutive irreversible first order reactions. The influences of the kinetic parameters (k(1d), k(2m), k(2a), R-m(max), t(max), J(d)(max), J(a)(max)) for the various stirring speeds in the system were established. The removal and recovery efficiencies of the cyanide ions transported from aqueous solutions in 360 min were 99.4 and 82%, respectively. As the stirring speed was increased, both the efficiency of transport and recovery of cyanide ions from aqueous solutions were increased. On the other hand, for maximum membrane entrance (J(d)(max)) and exit (J(a)(max)) fluxes the activation energies were calculated as 21.6 kcal/mol and 10.5 kcal/mol, respectively.
BibTeX:
@article{Aydiner2005,
  author = {Aydiner, C. and Kobya, M. and Demirbas, E.},
  title = {Cyanide ions transport from aqueous solutions by using quaternary ammonium salts through bulk liquid membranes},
  journal = {Desalination},
  year = {2005},
  volume = {180},
  number = {1-3},
  pages = {139--150},
  url = {://WOS:000231944600016},
  doi = {10.1016/j.desal.2005.01.003}
}
Aydiner C, Demir I and Yildiz E (2005), "Modeling of flux decline in crossflow microfiltration using neural networks: the case of phosphate removal", Journal of Membrane Science. Vol. 248(1-2), pp. 53-62.
Abstract: Flux declines versus time (t) during crossflow microfiltration of a mixture that contains phosphate and fly ash, were modeled and compared by using an artificial neural network (ANN) and Koltuniewicz's method (KM) at different conditions of fly ash dosages (C-FA), PO4 concentrations (C-PO4), transmembrane pressures (DeltaP) and two membrane types (M-T). Two different neural network (NN) architectures (NN1, NN2) that gave the best prediction of flux values were established for data analyses. KM was also taken as Kl and K2 to compare the predictions of both models at the same experiments separately. It was shown that all of the experimental conditions can be modeled as a whole or separately, and the model results obtained for one experiment can be used for others at the same conditions with an acceptable correlation level by NNs while not with Koltuniewicz. The correlation values were found as 0.991 and 0.988 for NN1 and NN2, and 0.972 and 0.973 for Kl and K2, respectively. These results are put forward to show that ANN results fit better to fluxes than KM according to correlation values (r(2)). The normalized flux values obtained from K1 and K2, smaller than 0.4, are in the range between -30 and 40% variations, whereas the most of N1 and N2 variations are in the range of +/-20%. The error distributions of data used for NN1 and NN2 were found to be 82 and 79%, while for K1 and K2 was calculated to be 51 and 52%, in the range of +/-10% error, respectively. The contribution of t variable to flux values provided by NNs was determined in an important level at the range of 40-50% due to increasing in membrane fouling by the time. The contributions of DeltaP, C-FA and C-PO4 variables were found in the range of 15-25%. The affect of MT was determined at a lower level about for 4%. As a conclusion, using elaborated ANN modeling, it is able to predict the permeate flux at a high accuracy from process variables such as transmembrane pressure, various concentrations of feed solution and membrane type and contributions of process variables to the permeate flux value. (C) 2004 Elsevier B.V. All rights reserved.
BibTeX:
@article{Aydiner2005a,
  author = {Aydiner, C. and Demir, I. and Yildiz, E.},
  title = {Modeling of flux decline in crossflow microfiltration using neural networks: the case of phosphate removal},
  journal = {Journal of Membrane Science},
  year = {2005},
  volume = {248},
  number = {1-2},
  pages = {53--62},
  url = {://WOS:000226883300006},
  doi = {10.1016/j.memsci.2004.07.036}
}
Inan H and Baykal BB (2005), "Clinoptilolite: a possible support material for nitrifying biofilms for effective control of ammonium effluent quality?", Water Science and Technology. Vol. 51(11), pp. 63-70.
Abstract: Ammonium selective natural zeolite clinoptilolite is suggested as a possible support material for nitrifying biofilms to help improve effluent ammonium quality through its high capacity of ammonium removal in the process of ion exchange. This will especially be helpful in cases where the biofilter receives peak or variable loads routinely or occasionally. At the time of peak loads or shocks of ammonium, ion exchange capacity will provide a buffer for the effluent ammonium quality. Data to support this suggestion is presented.
BibTeX:
@article{Inan2005,
  author = {Inan, H. and Baykal, B. B.},
  title = {Clinoptilolite: a possible support material for nitrifying biofilms for effective control of ammonium effluent quality?},
  journal = {Water Science and Technology},
  year = {2005},
  volume = {51},
  number = {11},
  pages = {63--70},
  url = {://WOS:000231408900009}
}
Kobya M, Demirbas E, Senturk E and Ince M (2005), "Adsorption of heavy metal ions from aqueous solutions by activated carbon prepared from apricot stone", Bioresource Technology. Vol. 96(13), pp. 1518-1521.
Abstract: Apricot stones were carbonised and activated after treatment with sulphuric acid (1:1) at 200 degrees C for 24 h. The ability of the activated carbon to remove Ni(II), Co(II), Cd(II), Cu(II), Pb(II), Cr(III) and Cr(VI) ions from aqueous solutions by adsorption was investigated. Batch adsorption experiments were conducted to observe the effect of pH (1-6) on the activated carbon. The adsorptions of these metals were found to be dependent on solution pH. Highest adsorption occurred at 1-2 for Cr(VI) and 3-6 for the rest of the metal ions, respectively. Adsorption capacities for the metal ions were obtained in the descending order of Cr(VI) > Cd(II) > Co(II) > Cr(III) > Ni(II) > Cu(II) > Pb(II) for the activated carbon prepared from apricot stone (ASAC). (c) 2005 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Kobya2005,
  author = {Kobya, M. and Demirbas, E. and Senturk, E. and Ince, M.},
  title = {Adsorption of heavy metal ions from aqueous solutions by activated carbon prepared from apricot stone},
  journal = {Bioresource Technology},
  year = {2005},
  volume = {96},
  number = {13},
  pages = {1518--1521},
  url = {://WOS:000230062000014},
  doi = {10.1016/j.biortech.2004.12.005}
}
Kobya A, Aydiner C and Demirbas E (2005), "Non-steady-state kinetic analysis of coupled transport of thiocyanate ions through binary liquid membranes", Desalination. Vol. 175(2), pp. 237-246.
Abstract: The coupled transport of thiocyanate (SCN-) ions through binary liquid membranes of various compositions was investigated using trichloromethane and dichloromethane as membrane components in non-steady-state kinetics. The influence of the membrane composition on the kinetic parameters (k(1d), k(2m), k(2a), R-m(max),t(max)) were calculated. The present work shows the importance of the nature of binary liquid membranes in establishing transport efficiency, which is increased by varying membrane composition. Striking variations of the kinetic parameters with the membrane composition were observed. It is shown that transport kinetics obeys the competitive preferential solvation theory in the whole concentration range.
BibTeX:
@article{Kobya2005a,
  author = {Kobya, A. and Aydiner, C. and Demirbas, E.},
  title = {Non-steady-state kinetic analysis of coupled transport of thiocyanate ions through binary liquid membranes},
  journal = {Desalination},
  year = {2005},
  volume = {175},
  number = {2},
  pages = {237--246},
  url = {://WOS:000230252500010},
  doi = {10.1016/j.desal.2004.10.011}
}
Kurt A, Ozkan M, Sezen K, Demirbag Z and Ozcengiz G (2005), "Cry3Aa11: A new Cry3Aa delta-endotoxin from a local isolate of Bacillus thuringiensis", Biotechnology Letters. Vol. 27(15), pp. 1117-1121.
Abstract: A local isolate of Bacillus thuringiensis Mm2 had insecticidal activity against the larvae of Melolontha melolontha, Agelastica alni, Leptinotarsa decemlineata and Amphimallon solstitiale and produced a 65 kDa protein. SDS-PAGE profile of B. thuringiensis Mm2 was compared with those of 29 different Cry3Aa producers which verified Cry3Aa biosynthesis by the isolate. The cry3Aa gene of Mm2 was cloned, sequenced and the deduced amino acid sequence was compared with the cry3Aa sequences of ten different quaternary ranks. Its identity to these sequences ranged between 97.4% and 99.2%. The gene was next cloned into E. coli-Bacillus shuttle vector pNW33N and expressed at a low level in B. subtilis 168.
BibTeX:
@article{Kurt2005,
  author = {Kurt, A. and Ozkan, M. and Sezen, K. and Demirbag, Z. and Ozcengiz, G.},
  title = {Cry3Aa11: A new Cry3Aa delta-endotoxin from a local isolate of Bacillus thuringiensis},
  journal = {Biotechnology Letters},
  year = {2005},
  volume = {27},
  number = {15},
  pages = {1117--1121},
  url = {://WOS:000231501100010},
  doi = {10.1007/s10529-005-8460-1}
}
Kurt A, Ozkan M and Ozcengiz G (2005), "Inorganic phosphate has a crucial effect on Cry3Aa delta-endotoxin production", Letters in Applied Microbiology. Vol. 41(4), pp. 303-308.
Abstract: Aims: The study aimed at increasing Cry3Aa delta-endotoxin production by a local isolate of Bacillus thuringiensis (B.t. strain Mm2). To this end, different nutritional conditions were tested for their effects on Cry3Aa yields. Methods and Results: Bacillus thuringiensis Mm2 was grown by shaking at 30 degrees C in different media. Samples were taken from the cultures at intervals and used for protein extraction. SDS-PAGE was performed for toxin analysis. Inclusion of inorganic phosphate (Pi) into the Difco's sporulation medium at an increased level of 200 mmol l(-1) caused a fivefold increase (from 3 to 15.6 mu g ml(-1)) in toxin production. Omission of FeSO4 from the medium decreased this yield by half. Resuspension experiments suggested catabolite repression of toxin biosynthesis by glucose. The inclusion of high Pi invariably increased toxin synthesis, even in the absence of sugars. Conclusions: Inorganic phosphate had the most striking effect on toxin biosynthesis. Iron effect was found to be unique to our isolate whereas Pi effect seemed to be common to the biosynthesis of Cry3Aa-type toxins. Stimulation of toxin synthesis by Pi did not seem to represent a relief from glucose repression. Significance and Impact of the Study: Bacillus thuringiensis is the most versatile biopesticide for use in pest management. Regarding cost-effectiveness of related fermentations, high Pi supplement drastically increases Coleoptera-specific toxin synthesis.
BibTeX:
@article{Kurt2005a,
  author = {Kurt, A. and Ozkan, M. and Ozcengiz, G.},
  title = {Inorganic phosphate has a crucial effect on Cry3Aa delta-endotoxin production},
  journal = {Letters in Applied Microbiology},
  year = {2005},
  volume = {41},
  number = {4},
  pages = {303--308},
  url = {://WOS:000231864000002},
  doi = {10.1111/j.1472-765X.2005.01776.x}
}
Nuhoglu A, Keskinler B and Yildiz E (2005), "Mathematical modelling of the activated sludge process - the Erzincan case", Process Biochemistry. Vol. 40(7), pp. 2467-2473.
Abstract: In this study, simulation results for a full-scale wastewater treatment plant (WWTP) of Erzincan city, which is located at the east of Turkey and serving 124,000 population equivalents, are presented. The dynamic behaviour of simultaneous carbon removal and nitrification process carried out in an Carrousel type aerator and also the clarification-thickening function of final settler were modelled employing activated sludge model 1 (ASM 1) and a dynamic model, respectively. In the first step of the study, detailed wastewater characterization required by the process models were performed and the variables such as readily (Ss) and slowly biodegradable (Xs) substrates were analysed with a respirometric technique. Simulations were performed using pre-compiled model and layout implemented in GPS-X simulation software. Daily values of parameters such as Soluble and Total COD, total nitrogen, suspended solids, NO3-N, NH4-N, organic-N, soluble inert substrate (S-I), S-s and X-s were used as input data. In model calibration, it was determined that the change in the default values of four model parameters gave a reasonable match for investigated variables. (c) 2004 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Nuhoglu2005,
  author = {Nuhoglu, A. and Keskinler, B. and Yildiz, E.},
  title = {Mathematical modelling of the activated sludge process - the Erzincan case},
  journal = {Process Biochemistry},
  year = {2005},
  volume = {40},
  number = {7},
  pages = {2467--2473},
  url = {://WOS:000228221800026},
  doi = {10.1016/j.procbio.2004.09.011}
}
Oguz E, Keskinler B and Celik Z (2005), "Ozonation of aqueous Bomaplex Red CR-L dye in a semi-batch reactor", Dyes and Pigments. Vol. 64(2), pp. 101-108.
Abstract: The ozonation of synthetic wastewater containing Bomaplex Red CR-L dye has been realized in a semi-batch reactor. In this study, the dye and COD removal from synthetic textile wastewater has been studied by ozonation as functions of initial dye concentration (400, 600, 800 and 1000 mg L-1), temperature (18, 40 and 70 degreesC, ozone-air flow rate (5, 10 and 15 L min(-1)), pH (3, 6, 9.3 and 12) and ozone generation percentage (0.7, 1.1 and 1.4 O-3%). The efficiency of dye removal has increased with increasing pH, ozone generation rate, and decreased with increasing temperature, but not changed with increasing ozone-air flow rate and initial dye concentration. The efficiency of COD removal from synthetic wastewater has increased with increasing pH, ozone generation percentage, but scarcely changed with increasing initial dye concentration and ozone-air flow rate, but the efficiency of COD removal decreased with increasing temperature. In this study, dye removal from synthetic wastewater in excess of 99% was obtained at an oxidation time of 15 min. The efficiencies of COD removal were between 56 and 35% at an oxidation time of 30 min. At the end of the study, it was concluded that ozonization is an efficient process for dye removal from synthetic wastewater of Bomaplex Red CR-L, but alone ozonization was not an efficient method to remove all the COD from the textile wastewater. (C) 2004 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Oguz2005,
  author = {Oguz, E. and Keskinler, B. and Celik, Z.},
  title = {Ozonation of aqueous Bomaplex Red CR-L dye in a semi-batch reactor},
  journal = {Dyes and Pigments},
  year = {2005},
  volume = {64},
  number = {2},
  pages = {101--108},
  url = {://WOS:000225331300002},
  doi = {10.1016/j.dyepig.2004.04.009}
}
Oguz E and Keskinler B (2005), "Determination of adsorption capacity and thermodynamic parameters of the PAC used for bomaplex red CR-L dye removal", Colloids and Surfaces a-Physicochemical and Engineering Aspects. Vol. 268(1-3), pp. 124-130.
Abstract: In this study, powder activated carbon (PAC) was used to remove Bomaplex Red CR-L dye from aqueous solutions. The influence of suspension pH, temperature, agitation rate, and the PAC dosage on Bomaplex Red CR-L dye removal and adsorption capacity was investigated by conducting a series of batch adsorption experiments. In addition, the mechanism of the dye removal was explained on the basis of the results of fourier transform infrared spectroscopy (FTIR). In order to gather information about adsorption mechanism at various pHs, electrophoretic mobilites of particles were measured. According to the BET (N2) measurements, the specific surface area of the PAC was found as 465 m(2)/g. The adsorption constants were defined according to Freundlich, Langmuir, BET and D-R isotherm models. The experimental adsorption data were fitted to Freundlich adsorption model (R-2 = 0.98). Thermodynamic parameters such as Delta H degrees, Delta S degrees and Delta G degrees were calculated from the slope and intercept of linear plot of log K-c against (I/T) x 1000. In this study, at the result of a 30 min reaction time, the max dye removal efficiency and adsorption capacity were obtained as 99% and 83 mg/g, respectively. (c) 2005 Elsevier B.V. All rights reserved.
BibTeX:
@article{Oguz2005a,
  author = {Oguz, E. and Keskinler, B.},
  title = {Determination of adsorption capacity and thermodynamic parameters of the PAC used for bomaplex red CR-L dye removal},
  journal = {Colloids and Surfaces a-Physicochemical and Engineering Aspects},
  year = {2005},
  volume = {268},
  number = {1-3},
  pages = {124--130},
  url = {://WOS:000233079200020},
  doi = {10.1016/j.colsurfa.2005.06.026}
}
Oncel MS, Ince M and Bayramoglu M (2005), "Leaching of silver from solid waste using ultrasound assisted thiourea method", Ultrasonics Sonochemistry. Vol. 12(3), pp. 237-242.
Abstract: Thiourea leaching of precious metals such as gold and silver from ores has several advantages when compared with conventional cyanidation process. In recent years, the use of ultrasound in leaching processes is becoming increasingly popular in hydrometallurgy. This paper deals with combining these two techniques for silver leaching from solid waste of a cyanidation leach plant located in Kutahya, Turkey. The primary aim of this research is to assess the technical performance of the method. To achieve maximum leaching yield, eight process variables have been selected to estimate optimum process conditions by means of statistical factorial design and steepest ascent techniques. Laboratory-scale experiments showed that complete leaching of silver may be achieved by this process. (C) 2003 Elsevier B.V. All rights reserved.
BibTeX:
@article{Oncel2005,
  author = {Oncel, M. S. and Ince, M. and Bayramoglu, M.},
  title = {Leaching of silver from solid waste using ultrasound assisted thiourea method},
  journal = {Ultrasonics Sonochemistry},
  year = {2005},
  volume = {12},
  number = {3},
  pages = {237--242},
  url = {://WOS:000224891000015},
  doi = {10.1016/j.ultsonch.2003.10.007}
}
Onkal-Engin G, Demir I and Engin SN (2005), "e-NOSE response classification of sewage odors by neural networks and fuzzy clustering", In Advances in Natural Computation, Pt 2, Proceedings. Vol. 3611, pp. 648-651.
Abstract: Each stage of the sewage treatment process emits odor causing compounds and these compounds may vary from one location in a sewage treatment works to another. In order to determine the boundaries of legal standards, reliable and efficient odor measurement methods need to be defined. An electronic NOSE equipped with 12 different polypyrrole sensors is used for the purpose of characterizing sewage odors. Samples collected at different locations of a WWTP were classified using a fuzzy clustering technique and a neural network trained with a back-propagation algorithm.
BibTeX:
@incollection{Onkal-Engin2005,
  author = {Onkal-Engin, G. and Demir, I. and Engin, S. N.},
  editor = {Wang, L. and Chen, K. and Ong, Y. S.},
  title = {e-NOSE response classification of sewage odors by neural networks and fuzzy clustering},
  booktitle = {Advances in Natural Computation, Pt 2, Proceedings},
  year = {2005},
  volume = {3611},
  pages = {648--651},
  url = {://WOS:000232222500092}
}
Onkal-Engin G, Demir I and Engin SN (2005), "Determination of the relationship between sewage odour and BOD by neural networks", Environmental Modelling & Software. Vol. 20(7), pp. 843-850.
Abstract: Sewage treatment works are one of the major sources that cause atmospheric odour pollution. Due to the increase in environmental concerns, there is a growing number of complaints on odour nuisance. In order to determine the boundaries of legal standards. reliable and efficient odour measurement methods need to be defined. An electronic nose was used for the purpose of characterising sewage odours. Samples collected at different locations of a wastewater treatment plant were classified using an Artificial Neural Network (ANN) trained with a back-propagation algorithm. Additionally, the same method was used to determine the relation between sewage sample odours and their related Biochemical Oxygen Demand (BOD) values. The overall results have indicated that ANNs can be used to classify the sewage samples collected from different locations of a wastewater treatment plant. Moreover, the electronic nose output could be used as an indicator in monitoring the biochemical activities of wastewaters. (c) 2004 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Onkal-Engin2005a,
  author = {Onkal-Engin, G. and Demir, I. and Engin, S. N.},
  title = {Determination of the relationship between sewage odour and BOD by neural networks},
  journal = {Environmental Modelling & Software},
  year = {2005},
  volume = {20},
  number = {7},
  pages = {843--850},
  url = {://WOS:000227657400003},
  doi = {10.1016/j.envsoft.2004.04.012}
}
Sinirkaya M, Kocakerim MM, Boncukcuoglu R, Kucuk O and Oncel S (2005), "Recovery of boron from tincal wastes", Industrial & Engineering Chemistry Research. Vol. 44(3), pp. 427-433.
Abstract: Boron ores are some of Turkey's most important underground riches. Tincal (Na-2,B4O7-10H(2)O), having the largest deposit, originally contains clay minerals such as illite and montmorillonite. One of the most important problems in refined borax production is separating tincal from the clay minerals, which are in a colloidal state in an aqueous solution and cannot be filiered. To separate clay particles, various additives are used as coagulants and cause both increasing production cost and borax loss. In this study, the reactor waste forming during borax production from tincal ore was dissolved in distilled water, CO2-saturated water, and SO2-saturated water to recover its B2O3 contents, to investigate dissolution kinetics: and to determine the filtration conditions in these dissolving media. The dissolution kinetics of tincal waste were investigated by choosing the temperature as a parameter, and it was found that activation energies and Arrhenius constants were 62.2 kJ mol(-1) and 1.8 x 10(10) for SO2-saturated water and 24.5 kJ. mol(-1) and 1.6 x 10(4) for CO2-saturated water, respectively. On the other hand. the effects of passing SO2 and CO2 gases through a tincal solution on spoiling the colloidal state of clay minerals were studied by using the temperature and stirring time for dissolution as parameters. It was seen that the colloidal state could be spoiled by passing SO2 or CO2 gases through the suspension. The filtration rate increased by increasing the temperature and stirring time for dissolution when SO2-saturated water was used, but filtration was difficult in CO2-saturated water and impossible in distilled water.
BibTeX:
@article{Sinirkaya2005,
  author = {Sinirkaya, M. and Kocakerim, M. M. and Boncukcuoglu, R. and Kucuk, O. and Oncel, S.},
  title = {Recovery of boron from tincal wastes},
  journal = {Industrial & Engineering Chemistry Research},
  year = {2005},
  volume = {44},
  number = {3},
  pages = {427--433},
  url = {://WOS:000226634200001},
  doi = {10.1021/ie049705q}
}
Yildiz E, Keskinler B, Pekdemir T, Akay G and Nuhoglu A (2005), "High strength wastewater treatment in a jet loop membrane bioreactor: kinetics and performance evaluation", Chemical Engineering Science. Vol. 60(4), pp. 1103-1116.
Abstract: Treatment of wastewater containing high organic matter was investigated by means of a jet loop bioreactor combined with a membrane process. Volume of jet loop bioreactor and area of membrane filtration unit were 231 and 155 cm(2) respectively. It was found that jet loop reactor had high mass transfer coefficient (K(L)a) varying from 58.8 to 486 h(-1) depending on the water flow rate (i.e. power input) and air flow rate. Oxygen transfer efficiency and oxygenation capacity of the reactor varied from 12 to 22.5% and from 0.2 to 1.8 kg O-2 kW(-1), respectively. The efficiency of jet loop membrane bioreactor was found to be approximately 97% for a volumetric organic load of 2-97 kg COD/m(3) day over a period of 10 weeks. The reactor was not disturbed from the organic loads up to 68 kg COD/m3 day, but the treatment efficiency decreased to about 60% at higher organic loads. This decrease was due to insufficient oxygen transfer rate. The relationship between the effluent substrate concentration and the specific oxygen uptake rate (SOUR) values was determined. Applied food/microorganism (F/M) ratio was varied between 2.5 and 17 day(-1). Critical sludge age of the system (Theta(c)(m)) was evaluated to be 7.2 h. Sludge with unsatisfactory settling characteristics formed at high F/M values under turbulent conditions. Therefore, membrane process was used for solid-liquid separation and effluent solid concentration was approximately zero. Specific cake resistances (alpha) changed with F/M ratio. It was found that permeate fluxes were significantly effected with F/M ratio much more than mixed liquor suspended solids (MLSS). Average flux was 2.50 m(3)/m(2) day for 0.2 mum pore sized cellulose acetate membrane. It was concluded that the jet loop membrane bioreactor has distinctive advantages such as the ability to treat high strength wastewater, low area requirements and easy operation. (C) 2004 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Yildiz2005,
  author = {Yildiz, E. and Keskinler, B. and Pekdemir, T. and Akay, G. and Nuhoglu, A.},
  title = {High strength wastewater treatment in a jet loop membrane bioreactor: kinetics and performance evaluation},
  journal = {Chemical Engineering Science},
  year = {2005},
  volume = {60},
  number = {4},
  pages = {1103--1116},
  url = {://WOS:000226769600018},
  doi = {10.1016/j.ces.2004.09.071}
}
Yilmaz AE, Boncukcuoglu R, Kocakerim MM and Keskinler B (2005), "The investigation of parameters affecting boron removal by electrocoagulation method", Journal of Hazardous Materials. Vol. 125(1-3), pp. 160-165.
Abstract: Boron removal from wastewaters by electrocoagulation using aluminum electrode material was investigated in this paper. Several working parameters, such as pH, current density, boron concentration and type and concentration of supporting electrolyte were studied in an attempt to achieve a higher removal capacity. The experiments were carried out by keeping the pH of solution constant and optimum pH of solution was determined 8.0 for the aluminum electrode. Although energy consumption increased with decreasing boron concentration, which conductivity of these solutions were low, boron removal efficiency was higher at 100 mg/L than that of 1000 mg/L. Current density was an important parameter affecting removal efficiency. Boron removal efficiency and energy consumption increased with increasing current density from 1.2 to 6.0 mA/cm(2). The types of different supporting electrolyte were experimented in order to investigate to this parameter effect on boron removal. The highest boron removal efficiency, 97%, was found by CaCl2 Added CaCl2 increased more the conductivity of solution according to other supporting electrolytes, but decreased energy consumption. The results showed to have a high effectiveness of the electrocoagulation method in removing boron from aqueous solutions. (c) 2005 Elsevier B.V. All rights reserved.
BibTeX:
@article{Yilmaz2005,
  author = {Yilmaz, A. E. and Boncukcuoglu, R. and Kocakerim, M. M. and Keskinler, B.},
  title = {The investigation of parameters affecting boron removal by electrocoagulation method},
  journal = {Journal of Hazardous Materials},
  year = {2005},
  volume = {125},
  number = {1-3},
  pages = {160--165},
  url = {://WOS:000231914900018},
  doi = {10.1016/j.jhazmat.2005.05.020}
}
Akyol A, Yatmaz HC and Bayramoglu M (2004), "Photocatalytic decolorization of remazol red RR in aqueous ZnO suspensions", Applied Catalysis B-Environmental. Vol. 54(1), pp. 19-24.
Abstract: The photocatalytic decolorization of aqueous solutions of Remazol Red RR, a commercial azo-reactive textile dye, in the presence of various semiconductor powder suspensions has been investigated in a quartz batch reactor with the use of artificial light sources (UV-C). ZnO and TiO2 have been found the most active photocatalysts; however ZnO indicated slightly higher efficiency. The effects of various process variables on decolorization performance of the process have been investigated. The results showed that the decolorization efficiency increases with increase in pH, attaining maximum value at pH 10 for ZnO. The zero-point charge for ZnO is 9.0 above which ZnO surface is negatively charged by adsorbed OH- ions, favoring the formation of strong oxidant OH* radicals. The efficiency is inversely related to the dye concentration; increasing dye concentration enhances dye adsorption on the active sites of the catalyst surface, and consequently hinders OH- adsorption on the same sites, this results with a decreasing OH* formation rate. (C) 2004 Elsevier B.V. All rights reserved.
BibTeX:
@article{Akyol2004,
  author = {Akyol, A. and Yatmaz, H. C. and Bayramoglu, M.},
  title = {Photocatalytic decolorization of remazol red RR in aqueous ZnO suspensions},
  journal = {Applied Catalysis B-Environmental},
  year = {2004},
  volume = {54},
  number = {1},
  pages = {19--24},
  url = {://WOS:000224354900003},
  doi = {10.1016/j.apcatb.2004.05.021}
}
Basar CA, Karagunduz A, Cakici A and Keskinler B (2004), "Removal of surfactants by powered activated carbon and microfiltration", Water Research. Vol. 38(8), pp. 2117-2124.
Abstract: Direct and indirect releases of large quantities of surfactants to the environment may result in serious health and environmental problems. Therefore, surfactants should be removed from water before release to the environment or delivery for public use. Using powdered activated carbon (PAC) as adsorbent and separating particles with a membrane may be an effective technique to remove surfactants. In this study, the removal of surfactants by microfiltration and PAC was investigated and the influences of the operating parameters on the effectiveness on microfiltration were determined. An anionic (LABS) and a cationic surfactant (CTAB) were selected for the experiments. A series of batch experiments were performed to determine the sorption isotherms of surfactants to PAC. Then microfiltration experiments were carried out. The results showed that formation of secondary membrane on the surface and, within the pores of the membrane, increased the retention of surfactants significantly. Increase in transmembrane pressure and pore size of the membrane decreased the rejection rates, but increase in cross-flow velocity increased the rejection rate. Temperature had no apparent affect on the efficiency of surfactant removal. Presence of electrolyte had different effects on CTAB and LABS. The rejection rates of CTAB significantly increased when the concentration of NaCl increased; however, a slight decrease was observed in the rejection rate of LABS at the same conditions. (C) 2004 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Basar2004,
  author = {Basar, C. A. and Karagunduz, A. and Cakici, A. and Keskinler, B.},
  title = {Removal of surfactants by powered activated carbon and microfiltration},
  journal = {Water Research},
  year = {2004},
  volume = {38},
  number = {8},
  pages = {2117--2124},
  url = {://WOS:000221204500019},
  doi = {10.1016/j.watres.2004.02.001}
}
Bayramoglu M, Kobya M, Can OT and Sozbir M (2004), "Operating cost analysis of electrocoagulation of textile dye wastewater", Separation and Purification Technology. Vol. 37(2), pp. 117-125.
Abstract: Electrocoagulation (EC) is an efficient method for textile wastewater treatment. Researches are mainly focused on the technical performance of this process, while its economic aspect has been Usually neglected. This paper deals with a simplified operating cost analysis for the treatment of a textile wastewater by EC using iron and aluminium electrode materials. The effects of various parameters such as wastewater conductivity and pH, current density and operating time, on the operating cost have been discussed for two electrode materials, separately. (C) 2003 Elsevier B.V. All rights reserved.
BibTeX:
@article{Bayramoglu2004,
  author = {Bayramoglu, M. and Kobya, M. and Can, O. T. and Sozbir, M.},
  title = {Operating cost analysis of electrocoagulation of textile dye wastewater},
  journal = {Separation and Purification Technology},
  year = {2004},
  volume = {37},
  number = {2},
  pages = {117--125},
  url = {://WOS:000221939900003},
  doi = {10.1016/j.seppur.2003.09.002}
}
Bektas N and Soysal D (2004), "Kinetics of phosphate removal using surfactant modified clinoptilolite", Fresenius Environmental Bulletin. Vol. 13(4), pp. 366-369.
Abstract: In this work, the preliminary results on the removal pathways for phosphate ions from aqueous solution using surfactant-modified clinoptilolite (SMC) were investigated. The chemical kinetic describes the time course of reaction pathways to reach the equilibrium, whereas chemical equilibrium gives no information about pathways and reaction rates. Langmuir and Freundlich isotherm constants and correlation coefficients for the present system were calculated and compared. The equilibrium process of phosphate removal was described well by the Langmuir isotherm. The sorption kinetic was tested for Elovich, pseudo-first order and pseudo-second order reaction models. The rate constants of sorption for all these kinetic models were calculated. The pseudo-second order kinetic reaction model was found to be the best for correlation of the data for phosphate removal from aqueous solution using modified clinoptilolite.
BibTeX:
@article{Bektas2004,
  author = {Bektas, N. and Soysal, D.},
  title = {Kinetics of phosphate removal using surfactant modified clinoptilolite},
  journal = {Fresenius Environmental Bulletin},
  year = {2004},
  volume = {13},
  number = {4},
  pages = {366--369},
  url = {://WOS:000221097500012}
}
Bektas N, Oncel S, Akbulut HY and Dimoglo A (2004), "Removal of boron by electrocoagulation", Environmental Chemistry Letters. Vol. 2(2), pp. 51-54.
Abstract: Boron compounds are used in many manufacturing products and may be introduced into the environment in the form of hazardous materials. Here the feasibility of removal of boron from aqueous solutions by electrocoagulation was investigated. The process was examined under various factors in order to assess optimal operating conditions. The results showed that electrocoagulation for boron removal depends on current density, initial concentration and time. Under a current density of 30 mA/cm(2) the percentage of boron removal from aqueous solutions is in the range of 92-96%.
BibTeX:
@article{Bektas2004a,
  author = {Bektas, N. and Oncel, S. and Akbulut, H. Y. and Dimoglo, A.},
  title = {Removal of boron by electrocoagulation},
  journal = {Environmental Chemistry Letters},
  year = {2004},
  volume = {2},
  number = {2},
  pages = {51--54},
  url = {://WOS:000239113900001},
  doi = {10.1007/s10311-004-0075-6}
}
Bektas N and Kara S (2004), "Removal of lead from aqueous solutions by natural clinoptilolite: equilibrium and kinetic studies", Separation and Purification Technology. Vol. 39(3), pp. 189-200.
Abstract: In this study, the removal of lead ions from aqueous solution using natural clinoptilolite under different experimental conditions was investigated. The effects of the initial metal concentration, agitation speed, temperature and pH on the removal efficiency of lead were studied. Langmuir and Freundlich isotherm constants and correlation coefficients for the present system at different conditions were calculated and compared. The equilibrium process was described well by the Langmuir isotherm model with the maximum sorption capacity of 166 mg/g of lead on clinoptilolite. The sorption kinetics were tested for the first order reaction, intra-particle diffusion, pseudo-first order, and pseudo-second order reaction at different experimental conditions. The rate constants of sorption for all these kinetic models were calculated. Good correlation coefficients were obtained for the pseudo-second order kinetic model showing that lead uptake process followed the pseudo-second order rate expression. (C) 2003 Elsevier B.V. All rights reserved.
BibTeX:
@article{Bektas2004b,
  author = {Bektas, N. and Kara, S.},
  title = {Removal of lead from aqueous solutions by natural clinoptilolite: equilibrium and kinetic studies},
  journal = {Separation and Purification Technology},
  year = {2004},
  volume = {39},
  number = {3},
  pages = {189--200},
  url = {://WOS:000224049900006},
  doi = {10.1016/j.seppur.2003.12.001}
}
Bektas N, Akbulut H, Inan H and Dimoglo A (2004), "Removal of phosphate from aqueous solutions by electro-coagulation", Journal of Hazardous Materials. Vol. 106(2-3), pp. 101-105.
Abstract: The aim of this paper was to investigate the feasibility of the removal of phosphate from aqueous solution by electro-coagulation (EC). The current density (CD) between 2.5 and 10 mA cm(-2) and duration in the limits of 5-20 min were tried for different concentrations. In order to determine optimal operating conditions, the EC process used for the phosphate removal was examined in dependence with the CD, initial concentrations and time. The results of the experimental batch processing showed high effectiveness of the EC method in removing phosphate from aqueous solutions. 2003 (C) Elsevier B.V. All rights reserved.
BibTeX:
@article{Bektas2004c,
  author = {Bektas, N. and Akbulut, H. and Inan, H. and Dimoglo, A.},
  title = {Removal of phosphate from aqueous solutions by electro-coagulation},
  journal = {Journal of Hazardous Materials},
  year = {2004},
  volume = {106},
  number = {2-3},
  pages = {101--105},
  url = {://WOS:000189111700004},
  doi = {10.1016/j.jhazmat.2003.10.002}
}
Bektas N, Agim BA and Kara S (2004), "Kinetic and equilibrium studies in removing lead ions from aqueous solutions by natural sepiolite", Journal of Hazardous Materials. Vol. 112(1-2), pp. 115-122.
Abstract: The capacity of sepiolite for the removal of lead ions from aqueous solution was investigated under different experimental conditions. The Langmuir and Freundlich equations, which are in common use for describing sorption equilibrium for wastewater-treatment applications, were applied to data. The constants and correlation coefficients of these isotherm models for the present system at different conditions such as pH. temperature and particle size were calculated and compared. The equilibrium process was well described by the Langmuir isotherm model and the maximum sorption capacity was found to be 93.4 mg/g for the optimal experimental condition. The thermodynamic parameters (DeltaGdegrees, DeltaHdegrees and DeltaSdegrees) for lead sorption on the sepiolite were also determined from the temperature dependence. The influences of specific parameters such as the agitation speed, particle size and initial concentration for the kinetic studies were also examined. The sorption kinetics were tested for first order reversible, pseudo-first order and pseudo-second order reaction and the rate constants of kinetic models were calculated. The best correlation coefficients were obtained using the pseudo-second order kinetic model, indicating that lead uptake process followed the pseudo-second order rate expression. (C) 2004 Elsevier B.V. All rights reserved.
BibTeX:
@article{Bektas2004d,
  author = {Bektas, N. and Agim, B. A. and Kara, S.},
  title = {Kinetic and equilibrium studies in removing lead ions from aqueous solutions by natural sepiolite},
  journal = {Journal of Hazardous Materials},
  year = {2004},
  volume = {112},
  number = {1-2},
  pages = {115--122},
  url = {://WOS:000222722500012},
  doi = {10.1016/j.jhazmat.2004.04.015}
}
Bingol A, Ucun H, Bayhan YK, Karagunduz A, Cakici A and Keskinler B (2004), "Removal of chromate anions from aqueous stream by a cationic surfactant-modified yeast", Bioresource Technology. Vol. 94(3), pp. 245-249.
Abstract: The removal of chromate anions (CrO42-) from aqueous solution by a cationic surfactant-modified yeast was studied in a batch system. Cetyl trimethyl ammonium bromide (CTAB) was used for biomass modification; it substantially improved the biosorption efficiency. The influences of solution pH, CrO42- anion concentrations and biomass concentration on the biosorption efficiency were investigated. The biosorption of chromate anions by modified yeast was strongly affected by pH. The optimum pH for biosorption of CrO42- by modified yeast was 4.5-5.5. Zeta potential values of modified and unmodified yeast were determined at various pH values. Concentrations ranging from 5.2 to 208 mg/l Cr(VI) were tested and the biosorptive removal efficiency of the metal ions from aqueous solution was more than 99.5%. Freundlich and Langmuir isotherms were used to evaluate the data and the regression constants were determined. (C) 2004 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Bingol2004,
  author = {Bingol, A. and Ucun, H. and Bayhan, Y. K. and Karagunduz, A. and Cakici, A. and Keskinler, B.},
  title = {Removal of chromate anions from aqueous stream by a cationic surfactant-modified yeast},
  journal = {Bioresource Technology},
  year = {2004},
  volume = {94},
  number = {3},
  pages = {245--249},
  url = {://WOS:000222196200003},
  doi = {10.1016/j.biotech.2004.01.018}
}
Demirbas E, Kobya M, Senturk E and Ozkan T (2004), "Adsorption kinetics for the removal of chromium (VI) from aqueous solutions on the activated carbons prepared from agricultural wastes", Water Sa. Vol. 30(4), pp. 533-539.
Abstract: The batch removal of Cr(VI) from aqueous solution using low-cost adsorbents such as cornelian cherry, apricot stone and almond shell under different experimental conditions was investigated in this study. The influences of initial Cr(VI) ion concentration (20 to 300 mg(.)l(-1)), pH (1 to 4) and particle size (0.63 to 1.60 mm) have been reported. Adsorption of Cr(VI) is highly pH-dependent and the results indicate that the optimum pH for the removal was found to be 1 for all types of carbon. A comparison of kinetic models applied to the adsorption of Cr(VI) ions on the adsorbents was evaluated for the pseudo first-order, the pseudo second-order, Elovich and intraparticle diffusion kinetic models, respectively. Results show that the pseudo second-order kinetic model was found to correlate the experimental data well.
BibTeX:
@article{Demirbas2004,
  author = {Demirbas, E. and Kobya, M. and Senturk, E. and Ozkan, T.},
  title = {Adsorption kinetics for the removal of chromium (VI) from aqueous solutions on the activated carbons prepared from agricultural wastes},
  journal = {Water Sa},
  year = {2004},
  volume = {30},
  number = {4},
  pages = {533--539},
  url = {://WOS:000225053800013}
}
Erhan E, Yer E, Akay G, Keskinler B and Keskinler D (2004), "Phenol degradation in a fixed-bed bioreactor using micro-cellular polymer-immobilized Pseudomonas syringae", Journal of Chemical Technology and Biotechnology. Vol. 79(2), pp. 195-206.
Abstract: Highly porous (85% void volume) polymer beads with interconnecting micro-pores were prepared for the immobilization of Pseudomonas syringae for the degradation of phenol in a fixed-bed column bioreactor. The internal architecture of this support material (also known as PolyHIPE Polymer) could be controlled through processing before the polymerization stage. The transient and steady state phenol utilization rates were measured as a function of substrate solution flow rate and initial substrate concentration. The spatial concentration of the bacteria on the micro-porous support particles as well as within them was studied using scanning electron microscopy at various time intervals during the continuous operation of the bioreactor. It was found that although bacterial penetration into the porous support was present after 20 days, bacterial viability however, was compromised after 120 days as a result of the formation of a biofilm on the support particles. The steady state phenol utilization at an initial phenol concentration of 200 mg cm(-3) was 100% provided that the flow rate was less than 7 cm(3) min(-1). Substrate inhibition at a constant flow rate of 4.5 cm(3) min(-1) was found to begin at 720 mg dm(-3). The critical dilution rate for bacteria washout was high as a result of the highly hydrophobic nature of the support and the reduction of pore interconnect size due to bacterial growth within the pores in the vicinity of the surface of the support. (C) 2004 Society of Chemical Industry.
BibTeX:
@article{Erhan2004,
  author = {Erhan, E. and Yer, E. and Akay, G. and Keskinler, B. and Keskinler, D.},
  title = {Phenol degradation in a fixed-bed bioreactor using micro-cellular polymer-immobilized Pseudomonas syringae},
  journal = {Journal of Chemical Technology and Biotechnology},
  year = {2004},
  volume = {79},
  number = {2},
  pages = {195--206},
  url = {://WOS:000188500900012},
  doi = {10.1002/jctb.938}
}
Farizoglu B, Keskinler B, Yildiz E and Nuhoglu A (2004), "Cheese whey treatment performance of an aerobic jet loop membrane bioreactor", Process Biochemistry. Vol. 39(12), pp. 2283-2291.
Abstract: The raw chess whey (CW) treatment capacity of a jet loop membrane bioreactor (JLMBR) was evaluated. Raw CW was first characterized for carbonaceous, nitrogenous and phosphorus compounds. The total COD range of the raw CW was between 73 and 86 kg m(-3) and 82% of the total COD was found to be soluble. The JLMBR system, of 321 capacity was operated continuously for 3 months with a sludge age of 1.1-2.8 days and COD loads of 3.5-33.5 kg-COD m(-3) per day. A treatment efficiency of 97% was obtained for 1.6 days of sludge age and COD loads of 22.2 kg-COD m(-3) per day. The sludge flocks observed in the system were highly motile, dispersed and had poor settling properties. The membrane filtration characteristics of this sludge were investigated and increasing MLSS concentration decreased membrane flux values. (C) 2003 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Farizoglu2004,
  author = {Farizoglu, B. and Keskinler, B. and Yildiz, E. and Nuhoglu, A.},
  title = {Cheese whey treatment performance of an aerobic jet loop membrane bioreactor},
  journal = {Process Biochemistry},
  year = {2004},
  volume = {39},
  number = {12},
  pages = {2283--2291},
  url = {://WOS:000223925500063},
  doi = {10.1016/j.procbio.2003.11.028}
}
Inan H, Dimoglo A, Simsek H and Karpuzcu A (2004), "Olive oil mill wastewater treatment by means of electro-coagulation", Separation and Purification Technology. Vol. 36(1), pp. 23-31.
Abstract: The removal of chemical oxygen demand (COD), color and suspended solid (SS) from olive oil mill wastewater (OMWW) was experimentally investigated by using electro-coagulation (EC). Aluminum and iron were used in the reactor simultaneously as materials for electrodes. The reactor voltage was 12 V, current density (CD) was changing between 10 and 40 mA cm(-2), pH was taken equal to 4, 6, 7, and 9 units, and duration varied in the limits of 2-30 min. Under the 30-min retention time, 52% COD was removed by the aluminum anode and 42% was removed by the iron anode. CD efficiency versus the percent of COD removal was examined at the 10-min retention time for pH 6.2 +/- 10.2. It appeared that with the CD increase, the percent of COD removal was increasing as well. The color removal yield was examined as the result of using different retention times, current densities, and iron and aluminum as materials for anodes. CD values in the range of 10-40 mA cm(-2) were tested at the 10-min retention time each one; color removal was 90-97% by this. In this study the EC process was examined with the aim of determining the highest rate of SS removal from the OMWW as well. (C) 2003 Elsevier B.V. All rights reserved.
BibTeX:
@article{Inan2004,
  author = {Inan, H. and Dimoglo, A. and Simsek, H. and Karpuzcu, A.},
  title = {Olive oil mill wastewater treatment by means of electro-coagulation},
  journal = {Separation and Purification Technology},
  year = {2004},
  volume = {36},
  number = {1},
  pages = {23--31},
  url = {://WOS:000220302200003},
  doi = {10.1016/s1383-5866(03)00148-5}
}
Kazanci N, Leroy S, Ileri O, Emre O, Kibar M and Oncel S (2004), "Late holocene erosion in NW Anatolia from sediments of Lake Manyas, Lake Ulubat and the southern shelf of the Marmara Sea, Turkey", Catena. Vol. 57(3), pp. 277-308.
Abstract: This paper deals with modem and ancient sedimentation in fresh water lakes and the marine shelf of the southern Marmara region, NW Anatolia, Turkey. Most of the information has been obtained from monitoring of suspended load discharged into two lakes (Manyas and Ulubat) in the last 45 years and from 8 to 11 m thick lacustrine sediments, in addition to radiocarbon-dated shelf sediments. This allows a holistic approach to the drainage basin denudation over time. The results show that the sedimentation rates in the lakes were low 0.22 cm year(-1), from 4000 to 2000 years BP and then they increased (0.29 cm year(-1)) up to sub-recent times and reached 0.44 cm year(-1) in the last century. It is suggested that deforestation created high rates of sedimentation in the basins and/or strong denudation of the region during the Late Holocene. This study also shows that for shallow freshwater lakes the calculation of sedimentation rates must include fine particles lost by the outlets and coarse-grained bed load deposited on their shores. In addition, a high rate of sedimentation has been created by short, but repetitive intense depositions. During the last century particularly during the last 45 years, the rate of sedimentation or denudation has increased dramatically in NW Turkey. The two World Wars and mismanagement of the land had important local effects by increasing deforestation and resulting in the present erosive conditions. (C) 2003 Elsevier B.V. All rights reserved.
BibTeX:
@article{Kazanci2004,
  author = {Kazanci, N. and Leroy, S. and Ileri, O. and Emre, O. and Kibar, M. and Oncel, S.},
  title = {Late holocene erosion in NW Anatolia from sediments of Lake Manyas, Lake Ulubat and the southern shelf of the Marmara Sea, Turkey},
  journal = {Catena},
  year = {2004},
  volume = {57},
  number = {3},
  pages = {277--308},
  url = {://WOS:000222844900005},
  doi = {10.1016/j.catena.2003.11.004}
}
Keskinler B, Yildiz E, Erhan E, Dogru M, Bayhan Y and Akay G (2004), "Crossflow microfiltration of low concentration-nonliving yeast suspensions", Journal of Membrane Science. Vol. 233(1-2), pp. 59-69.
Abstract: Crossflow microfiltration of low concentration-nonliving yeast suspension was studied and effects of transmembrane pressure drop (DeltaP), membrane pore size and crossflow velocity on the membrane fluxes have been investigated. Filtration mechanism was explained by various flux decline models such as standard, intermediate, complete blocking and cake filtration. It was shown that permeate flux decay could be divided into three distinctive regions such as constant, rapid flux decay and slow flux decay periods by using relations of J(t)-t, t/V-V and V-t on the same plot. It was concluded that flux decline model fit to intermediate blocking model at the beginning of the filtration and then classical cake filtration became dominant filtration mechanism. It was found that specific cake resistance increased with increasing DeltaP. Compressibility coefficient (n) was calculated to be 1 and 0.39 for crossflow and dead-end filtration modes, respectively. Steady-state permeate fluxes increased with membrane pore size and crossflow velocity, and decreased with increasing yeast concentration. It was determined that pseudo-gel concentration on the membrane surface was 45 all and it was independent from crossflow velocity and membrane pore size. (C) 2004 Elsevier B.V. All rights reserved.
BibTeX:
@article{Keskinler2004,
  author = {Keskinler, B. and Yildiz, E. and Erhan, E. and Dogru, M. and Bayhan, Y. and Akay, G.},
  title = {Crossflow microfiltration of low concentration-nonliving yeast suspensions},
  journal = {Journal of Membrane Science},
  year = {2004},
  volume = {233},
  number = {1-2},
  pages = {59--69},
  url = {://WOS:000220761300007},
  doi = {10.1016/j.memsci.2003.12.014}
}
Keskinler B, Erhan E, Akay G, Kaya M and Bayguven B (2004), "Microfiltration of whey proteins adsorbed on yeast cells", International Journal of Food Science and Technology. Vol. 39(1), pp. 71-78.
Abstract: Soluble whey proteins (WPs), adsorbed on yeast cells, were recovered by a crossflow microfiltration (MF) technique using a cellulose nitrate membrane with a pore size of 0.45 mum. The crossflow velocity was 1.5 m s(-1) with a transmembrane pressure of 200 kPa at 25degreesC. A series of protein rejections occured at various pH values ranging from 2 to 8. WPs adsorbed more on to yeast cells at low pH (pH < 4) than at high pH values, probably because they were positively charged at low pH. It was also shown that permeate flux increased and Modified Membrane Fouling Index values decreased at low pH levels. When the yeast concentration was 50 g L-1, the flux decreased five times compared with that in the absence of yeast. Protein recovery increased with increasing yeast concentrations. The highest protein recovery was found to be 85% at a yeast concentration of 50 g L-1 at a steady state flux rate of 10(-6) m s(-1) at 25degreesC. When diluted solutions of whey were used, the same rejection of protein, adsorbed on yeast cells, was achieved at ten times lower amounts of yeast cells. This technique not only provides for the recovery of protein but also may give rise to the direct use of yeast cells, which are rich in protein, in the baking industry. WPs absorbed by yeast cells can be used to produce nutritionally rich products in areas where yeasts have been already used.
BibTeX:
@article{Keskinler2004a,
  author = {Keskinler, B. and Erhan, E. and Akay, G. and Kaya, M. and Bayguven, B.},
  title = {Microfiltration of whey proteins adsorbed on yeast cells},
  journal = {International Journal of Food Science and Technology},
  year = {2004},
  volume = {39},
  number = {1},
  pages = {71--78},
  url = {://WOS:000187405700008},
  doi = {10.1046/j.0950-5423.2003.00756.x}
}
Kobya M, Demirbas E, Demircioglu N, Yildirim Y and Yildiz YS (2004), "Effect of carrier type on coupled transport kinetics of thiocyanate ions through liquid membranes", Desalination. Vol. 160(3), pp. 253-262.
Abstract: Coupled transport of thiocyanate ions through a liquid membrane containing quaternary ammonium chloride salts in chloroform was examined. The influences of the carrier type in the membrane phase on the coupled transport of thiocyanate ions were investigated. The kinetics of the coupled transport were analyzed in the formalism of two consecutive irreversible first-order reactions and the kinetic parameters (k(1d), k(2m), k(2a), R-m(max), t(max), j(d)(max), J(a)(max)) were also calculated. For the coupled transport of thiocyanate ions, quaternary ammonium chloride salts having different carbon atom numbers (C-n) used as carriers were found to increase thiocyanate ions transport efficiency with increasing carbon atom numbers. Tetradecyl trimethylammonium chloride (TDTMACl), hexadecyl trimethylammonium chloride (HDTMACl), and tetraoctyl ammonium chloride (TOACl) were found to be the most effective carrier types for transport of thiocyanate ions when C-n is greater than 16. The activation energies for maximum membrane entrance and exit fluxes were calculated as 32.45 kJ/mol and 34.75 kJ/mol, respectively. The values of the activation energy indicate that the process is controlled by species diffusion.
BibTeX:
@article{Kobya2004,
  author = {Kobya, M. and Demirbas, E. and Demircioglu, N. and Yildirim, Y. and Yildiz, Y. S.},
  title = {Effect of carrier type on coupled transport kinetics of thiocyanate ions through liquid membranes},
  journal = {Desalination},
  year = {2004},
  volume = {160},
  number = {3},
  pages = {253--262},
  url = {://WOS:000188718800004},
  doi = {10.1016/s0011-9164(04)90027-6}
}
Kobya M, Demirbas E and Bayramoglu M (2004), "Modelling the effects of adsorbent dose and particle size on the adsorption of Cr(VI) ions from aqueous solutions", Adsorption Science & Technology. Vol. 22(7), pp. 583-594.
Abstract: Activated carbon was prepared from hazelnut shell with chemical carbonization using concentrated sulphuric acid. The adsorption tests were carried out in an agitated batch system with a fixed initial Cr(VI) ion concentration and varying adsorbent particle sizes and doses. The adsorption of Cr(VI) ions correlated strongly with these two variables. Two simple empirical models were examined for predicting the percentage of Cr(VI) ion adsorbed. Both models exhibited good correlation coefficients. The best model was selected on the basis of the standard deviation between the calculated and experimental values. The Freundlich adsorption isotherm provided the best correlation for the adsorption of Cr(VI) ions onto the carbon. This isotherm was used to fit the experimental adsorption capacity data and allowed the model parameters to be calculated and correlated with the particle size.
BibTeX:
@article{Kobya2004a,
  author = {Kobya, M. and Demirbas, E. and Bayramoglu, M.},
  title = {Modelling the effects of adsorbent dose and particle size on the adsorption of Cr(VI) ions from aqueous solutions},
  journal = {Adsorption Science & Technology},
  year = {2004},
  volume = {22},
  number = {7},
  pages = {583--594},
  url = {://WOS:000225929300006},
  doi = {10.1260/0263617042879465}
}
Kobya M (2004), "Removal of Cr(VI) from aqueous solutions by adsorption onto hazelnut shell activated carbon: kinetic and equilibrium studies", Bioresource Technology. Vol. 91(3), pp. 317-321.
Abstract: The adsorption Cr(VI) from aqueous solutions onto hazelnut shell activated carbon was carried out by varying the parameters such as pH, initial Cr(VI) concentration and temperature. The experimental data fitted well to the pseudo first-order kinetic model and then the rate constants were evaluated. The Langmuir isotherm provided the best correlation for Cr(VI) onto the activated carbon. Adsorption capacity was calculated from the Langmuir isotherm as 170 mg/g at an initial pH of 1.0 for the 1000 mg/l Cr(VI) solution. Thermodynamic parameters were evaluated and the adsorption is endothermic showing monolayer adsorption of Cr(VI). (C) 2003 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Kobya2004b,
  author = {Kobya, M.},
  title = {Removal of Cr(VI) from aqueous solutions by adsorption onto hazelnut shell activated carbon: kinetic and equilibrium studies},
  journal = {Bioresource Technology},
  year = {2004},
  volume = {91},
  number = {3},
  pages = {317--321},
  url = {://WOS:000188981700013},
  doi = {10.1016/j.biortech.2003.07.001}
}
Kobya M (2004), "Adsorption, kinetic and equilibrium studies of Cr(VI) by hazelnut shell activated carbon", Adsorption Science & Technology. Vol. 22(1), pp. 51-64.
Abstract: The adsorption of chromium(VI) from aqueous solutions on to hazelnut shell activated carbon (HSAC) was investigated. The adsorption was carried out by varying parameters such as the agitation time, the initial solution pH, the initial Cr(VI) concentration and the temperature. The experimental data were well fitted by the pseudo-first-order kinetic model allowing the rate constants to be evaluated. The Langmuir isotherm provided the best correlation for the adsorption of Cr(VI) onto the activated carbon. The adsorption of Cr(VI) was pH-dependent. The adsorption capacity as calculated from the Langmuir isotherm was 170 mg/g at an initial pH of 1.0 for a Cr(VI) solution of 1000 mg/l concentration. Thermodynamic parameters were evaluated, indicating that the adsorption was endothermic and involved monolayer adsorption of Cr(VI).
BibTeX:
@article{Kobya2004c,
  author = {Kobya, M.},
  title = {Adsorption, kinetic and equilibrium studies of Cr(VI) by hazelnut shell activated carbon},
  journal = {Adsorption Science & Technology},
  year = {2004},
  volume = {22},
  number = {1},
  pages = {51--64},
  url = {://WOS:000221000900005},
  doi = {10.1260/026361704323150999}
}
Nuhoglu A, Yildiz E, Keskinler B and Karpuzcu M (2004), "Wastewater characterization and performance upgrading of a domestic wastewater treatment plant: the Erzincan case", International Journal of Environment and Pollution. Vol. 21(5), pp. 440-456.
Abstract: A detailed characterization of the incoming wastewater and a performance evaluation were carried out for the domestic wastewater treatment plant of Erzincan City. Conventional characterization results showed that Erzincan has a medium strength wastewater quality. Structural characterization of the chemical oxygen demand (COD) indicated that the biodegradable fraction of the total COD was 64.7%. The soluble inert fraction was computed as 10.9% of the total COD. In Erzincan, an activated sludge plant provides secondary treatment using Carrousel treatment units. Because some operational problems, such as sludge bulking and foaming, have been experienced, and performance failures related to carbonaceous matter removal have been recorded many times, a new operational strategy suitable for this type of treatment plant was developed. In the new strategy the sludge age was kept at 22 days, intermittent aeration was abandoned and replaced by continuous aeration, and the sludge recycle ratio was increased to 1.35 from 0.85. The developed operational strategy showed its merit in that previous operational problems largely disappeared and COD concentrations remained below the Turkish discharge limits of 100 mg/l and the NH4 removal rate was in the range 87-95%.
BibTeX:
@article{Nuhoglu2004,
  author = {Nuhoglu, A. and Yildiz, E. and Keskinler, B. and Karpuzcu, M.},
  title = {Wastewater characterization and performance upgrading of a domestic wastewater treatment plant: the Erzincan case},
  journal = {International Journal of Environment and Pollution},
  year = {2004},
  volume = {21},
  number = {5},
  pages = {440--456},
  url = {://WOS:000222602000003},
  doi = {10.1504/ijep.2004.005119}
}
Oncel MS, Zedef V and Mert S (2004), "Lead contamination of roadside soils and plants in the highways between Istanbul and Sakarya, NW Turkey", Fresenius Environmental Bulletin. Vol. 13(12B), pp. 1525-1529.
Abstract: This study was conducted to determine the concentrations of lead in roadside topsoil and plants in roadside from two highways (TEM and D100) connecting Istanbul and Sakarya in the NW of Turkey. The concentrations of lead were measured by atomic absorption spectrophotometry (Perkin Elmer SIMAA 6000). Lead analyses showed that there was a considerable contamination in both soil and plants (corn shoot). The concentration of lead in the roadside soil and the plants were influenced by the traffic intensity. The mean lead concentrations in soils from TEM and D 100 were 110.12 mg/kg and 137.07 mg/kg, respectively. The average lead values in roadside corn shoots at TEM and D100 are 15.84 mg/kg and 39.22 mg/kg, respectively. The Pb concentrations of roadside soil and plant at D100 were higher than that of TEM. This could be the result of higher accumulation time of lead in D100, since it was built earlier than TEM. The Pb levels assessed in this study can be considered as toxic.
BibTeX:
@article{Oncel2004,
  author = {Oncel, M. S. and Zedef, V. and Mert, S.},
  title = {Lead contamination of roadside soils and plants in the highways between Istanbul and Sakarya, NW Turkey},
  journal = {Fresenius Environmental Bulletin},
  year = {2004},
  volume = {13},
  number = {12B},
  pages = {1525--1529},
  url = {://WOS:000226819600012}
}
Onkal-Engin G, Demir I and Hiz H (2004), "Assessment of urban air quality in Istanbul using fuzzy synthetic evaluation", Atmospheric Environment. Vol. 38(23), pp. 3809-3815.
Abstract: Little attention was paid to growing air quality concerns until about a decade earlier in Istanbul. With a population of over 12 million people and some occurred episodes imposed threats to the local government, and continuous monitoring of the urban air quality was started about a decade ago. This is part of a national strategy program which includes urban air quality assessment. This paper addresses a methodology for urban air quality using fuzzy synthetic evaluation techniques. The European part of Istanbul was selected for this purpose. Air pollutants data such as sulphur dioxide (SO2), carbon monoxide (CO), nitrogen dioxide (NO2) ozone (O-3), and total suspended particulate matter (PM) collected at five different air quality monitoring stations located in western part of Istanbul was used in this evaluation. The results obtained were compared to those applied to EPA air quality index. It was demonstrated that fuzzy synthetic evaluation techniques are quite appropriate techniques for air quality management. A case study was presented for this purpose. 2004 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Onkal-Engin2004,
  author = {Onkal-Engin, G. and Demir, I. and Hiz, H.},
  title = {Assessment of urban air quality in Istanbul using fuzzy synthetic evaluation},
  journal = {Atmospheric Environment},
  year = {2004},
  volume = {38},
  number = {23},
  pages = {3809--3815},
  url = {://WOS:000222569600008},
  doi = {10.1016/j.atmosenv.2004.03.058}
}
Pennell KD, Karagunduz A and Young MH (2004), "Impacts of surfactant adjuvants on pesticide availability and transport in soils", In Pesticide Decontamination and Detoxification. Vol. 863, pp. 231-245.
Abstract: Surfactants are frequently added to pesticide and herbicide formulations as adjuvants to improve handling, delivery and effectiveness. From a regulatory perspective such additives are generally considered to be inert, and their influence on co-contaminant fate and transport processes has been largely ignored. The objective of this chapter is to illustrate the potential effects of representative surfactant adjuvants on the phase distribution and availability of hydrophobic organic compounds (HOCs), soil water retention and water flow in unsaturated soils. Although the addition of surfactants at concentrations above the critical micelle concentration (CMC) is shown to enhance the total aqueous-phase concentration of HOCs, the free (non-micellar) aqueous phase HOC concentration decreases with increasing surfactant concentration. Results of pressure-saturation studies and one-dimensional column experiments demonstrate that surfactants can substantially reduce soil water retention and alter unsaturated water flow. These findings demonstrate the need to carefully consider the influence of surfactant adjuvants on both soil water characteristics and agrochemical fate and transport in the environment.
BibTeX:
@incollection{Pennell2004,
  author = {Pennell, K. D. and Karagunduz, A. and Young, M. H.},
  editor = {Gan, J. J. and Zhu, P. C. and Aust, S. D. and Lemley, A. T.},
  title = {Impacts of surfactant adjuvants on pesticide availability and transport in soils},
  booktitle = {Pesticide Decontamination and Detoxification},
  year = {2004},
  volume = {863},
  pages = {231--245},
  url = {://WOS:000186888400017}
}
Yatmaz HC, Akyol A and Bayramoglu M (2004), "Kinetics of the photocatalytic decolorization of an Azo reactive dye in aqueous ZnO suspensions", Industrial & Engineering Chemistry Research. Vol. 43(19), pp. 6035-6039.
Abstract: The photocatalytic decolorization of Remazol Red RR, a commercial azo reactive textile dye, in ZnO suspension, has been investigated in a quartz batch reactor with the use of artificial light source (UV-C). The reaction kinetics are modeled by pseudo-first-order rate law. Regression analysis related pseudo-first-order rate constant, k, to the catalyst loading, empirically as k proportional to [ZnO](0.6). The decolorization rate increases with increasing pH, attaining maximum value at pH 10. The rate constant is inversely related to the initial dye concentration, empirically according to the relation k proportional to [C-0](-1.5). Finally, the rate constant is found proportional to the square root of the light intensity as k proportional to [I] (0.5). These empirical models are therefore combined as k proportional to [ZnO](0.6) [Co](-1.5) [I](0.5).
BibTeX:
@article{Yatmaz2004,
  author = {Yatmaz, H. C. and Akyol, A. and Bayramoglu, M.},
  title = {Kinetics of the photocatalytic decolorization of an Azo reactive dye in aqueous ZnO suspensions},
  journal = {Industrial & Engineering Chemistry Research},
  year = {2004},
  volume = {43},
  number = {19},
  pages = {6035--6039},
  url = {://WOS:000223807400010},
  doi = {10.1021/ie049921z}
}
Yuksel E (2004), "Effect of specific energy variation on lateral overflows", Flow Measurement and Instrumentation. Vol. 15(5-6), pp. 259-269.
Abstract: A numerical model was used to study the effect of change in specific energy height along a side weir on flow. Discharge coefficient was considered as a local variable that includes flow depth and the angle of the deflected water jet along side weir. Hydraulic profile on the weir plane and the hydraulic head on the weir were obtained using two dimensionless parameters psi and m as a function of Froude number. Flow depths and flow rates were then computed and minimum standard errors were determined based upon these parameters. The agreement between computed values and observations was demonstrated. It was concluded that rates of flow are considerably affected by the variation of specific energy along the side weir when weir head is based on flow depth at the weir plane. Considerable deviations from the constant specific energy assumption may be observed in this case specially when a great change in flow rates exists along side weirs with zero end discharges. (C) 2004 Elsevier Ltd. All rights reserved.
BibTeX:
@article{Yuksel2004,
  author = {Yuksel, E.},
  title = {Effect of specific energy variation on lateral overflows},
  journal = {Flow Measurement and Instrumentation},
  year = {2004},
  volume = {15},
  number = {5-6},
  pages = {259--269},
  url = {://WOS:000225143000003},
  doi = {10.1016/j.flowmeasinst.2004.06.005}
}
Basar CA, Karagunduz A, Keskinler B and Cakici A (2003), "Effect of presence of ions on surface characteristics of surfactant modified powdered activated carbon (PAC)", Applied Surface Science. Vol. 218(1-4), pp. 169-174.
Abstract: Modification of surface characteristics of solids using surfactants has practical implications in industrial and environmental applications. Extensive research has been conducted to explore the mechanism of surfactant sorption to different solid surfaces. However, a clear understanding yet to be found especially for heterogeneous surfaces in which pores and structure show local differences. The main objective of this study was to determine the effects of ions on the surface potential of surface modified activated carbon. In order to achieve the objective, anionic and cationic surfactants were selected and adsorptions of these surfactants to powdered activated carbon (PAC) were investigated. Then, zeta potential measurements were conducted for the surface modified PAC and finally, the effects of mono- and di-valent anions and cations on the zeta potentials of PAC surface were investigated. The results showed that even at very low cetyl trimethyl ammonium bromide (CTAB) concentrations charge reversal was observed and substantial increase was observed in zeta potential. However, linearalkyl benzene sulfonate (LABS) showed somewhat gradual decrease in zeta potential, reaching maximum when maximum sorption capacity was attained. Presence of anions in addition to CTAB effected the change of zeta potential. Similar effects were also observed for LABS modified PAC in the presence of mono- and di-valent cations. The change of zeta potential of with the valance of cations and anions were linear. (C) 2003 Elsevier Science B.V. All rights reserved.
BibTeX:
@article{Basar2003,
  author = {Basar, C. A. and Karagunduz, A. and Keskinler, B. and Cakici, A.},
  title = {Effect of presence of ions on surface characteristics of surfactant modified powdered activated carbon (PAC)},
  journal = {Applied Surface Science},
  year = {2003},
  volume = {218},
  number = {1-4},
  pages = {169--174},
  url = {://WOS:000185491500022},
  doi = {10.1016/s0169-4332(03)00576-2}
}
Can OT, Bayramoglu M and Kobya M (2003), "Decolorization of reactive dye solutions by electrocoagulation using aluminum electrodes", Industrial & Engineering Chemistry Research. Vol. 42(14), pp. 3391-3396.
Abstract: The removal of pollutants from effluents by electrocoagulation has become an attractive method in recent years. This paper deals with the batch removal of the reactive textile dye Remazol Red RB 133 from an aqueous medium by the electrocoagulation method using aluminum electrodes. The effects of wastewater conductivity, initial pH, current density, stirring rate, dye concentration, and treatment time on the decolorization efficiency and energy consumption have been investigated. Aluminum hydroxypolymeric species formed during an earlier stage of the operation efficiently remove dye molecules by precipitation, and in a subsequent stage, AI(OH)3 flocs trap colloidal precipitates and make solid-liquid separation easier during the flotation stage. These stages of electrocoagulation must be optimized to design an economically feasible electrocoagulation process.
BibTeX:
@article{Can2003,
  author = {Can, O. T. and Bayramoglu, M. and Kobya, M.},
  title = {Decolorization of reactive dye solutions by electrocoagulation using aluminum electrodes},
  journal = {Industrial & Engineering Chemistry Research},
  year = {2003},
  volume = {42},
  number = {14},
  pages = {3391--3396},
  url = {://WOS:000183991400024},
  doi = {10.1021/ie020951g}
}
Farizoglu B, Nuhoglu A, Yildiz E and Keskinler B (2003), "The performance of pumice as a filter bed material under rapid filtration conditions", Filtration & Separation. Vol. 40(3), pp. 41-+.
Abstract: Deep bed sand filters are used extensively in drinking water and wastewater treatment. In this study, sand and pumice were used as a filtration media under rapid filtration conditions and performance results for both were compared. Turbidity removal performance and head losses were investigated as functions of filtration rate, bed depth and particle size. Under the same experimental conditions such as 750 mm bed depth, 7.64m(3)/m(2).h flow rate and, 0.5-1.0 mm grain size, turbidity removal rates for sand and pumice were found to be 85-90% and 98-99%, respectively. Furthermore, the head loss for sand and pumice were found to be 460 mm and 215 mm, respectively. The results obtained have shown that pumice has a high potential for use as a filter bed material.
BibTeX:
@article{Farizoglu2003,
  author = {Farizoglu, B. and Nuhoglu, A. and Yildiz, E. and Keskinler, B.},
  title = {The performance of pumice as a filter bed material under rapid filtration conditions},
  journal = {Filtration & Separation},
  year = {2003},
  volume = {40},
  number = {3},
  pages = {41-+},
  url = {://WOS:000182192100006},
  doi = {10.1016/s0015-1882(03)80137-4}
}
Gokcek E and Erturk F (2003), "Determination of CO and HC emissions for gasoline and LPG-fueled highway motor vehicles", Fresenius Environmental Bulletin. Vol. 12(10), pp. 1152-1157.
Abstract: Carbon monoxide (CO), unburned hydrocarbons (HCs), and oxides of nitrogen (NOx) are the major pollutants of motor vehicle emissions. The main fuel used in vehicular transportation is gasoline; the use of liquefied petroleum gas (LPG) is an alternative fuel, which can reduce the environmental impact on the transportation sector. Today, about 700.000 light-duty vehicles circulate in Istanbul and most of them are using aftermarket conversion systems. In this study we have surveyed 41 vehicles of that fleet. Twenty-six vehicles with carburettor systems were chosen, 11 were equipped with fuel injection and the remaining four vehicles with the newest technology avail-able for air pollution control. From the study, it can be concluded that due to poor maintenance, many of the in-use vehicles exceed the environmental regulation standards required for certification. After the tuning up of 41 vehicles, the emission values were reduced below the environmental regulation values. In addition, it was found that CO emission of LPG was 44% less than that of gasoline fuel.
BibTeX:
@article{Gokcek2003,
  author = {Gokcek, E. and Erturk, F.},
  title = {Determination of CO and HC emissions for gasoline and LPG-fueled highway motor vehicles},
  journal = {Fresenius Environmental Bulletin},
  year = {2003},
  volume = {12},
  number = {10},
  pages = {1152--1157},
  url = {://WOS:000186482100003}
}
Kobya M, Can OT and Bayramoglu M (2003), "Treatment of textile wastewaters by electrocoagulation using iron and aluminum electrodes", Journal of Hazardous Materials. Vol. 100(1-3), pp. 163-178.
Abstract: Treatment of textile wastewaters by electrocoagulation using iron and of aluminum electrode materials has been investigated in this paper. The effects of relevant wastewater characteristics such as conductivity and pH, and important process variables such as current density and operating time on the chemical oxygen demand (COD) and turbidity removal efficiencies have been explored. Furthermore, the electrode and energy consumptions for each electrode have been calculated. The results show that iron is superior to aluminum as sacrificial electrode material, from COD removal efficiency and energy consumption points. (C) 2003 Elsevier Science B.V. All rights reserved.
BibTeX:
@article{Kobya2003,
  author = {Kobya, M. and Can, O. T. and Bayramoglu, M.},
  title = {Treatment of textile wastewaters by electrocoagulation using iron and aluminum electrodes},
  journal = {Journal of Hazardous Materials},
  year = {2003},
  volume = {100},
  number = {1-3},
  pages = {163--178},
  url = {://WOS:000184062800013},
  doi = {10.1016/s0304-3894(03)00102-x}
}
Pekdemir T, Keskinler B, Yildiz E and Akay G (2003), "Process intensification in wastewater treatment: ferrous iron removal by a sustainable membrane bioreactor system", Journal of Chemical Technology and Biotechnology. Vol. 78(7), pp. 773-780.
Abstract: Biooxidation of ferrous iron (Fe(2+)) from strongly acidic industrial wastewater with a high Fe(2+) content by Thiobacillus ferrooxidans in a packed bed reactor and subsequent removal of ferric iron (Fe(3+)) by a crossflow microfiltration (membrane) process have been investigated as functions of wastewater flowrate (54-672 cm(3) h(-1)), Fe(2+) concentration (1.01-8.06 g dm(-3)), and pH (1.5-5.0). A natural (vegetable) sponge, Luffa cylindrica, was used as support matrix material. The fastest kinetic performance achieved was about 40 g Fe(2+) dm(-3) h(-1) at a true dilution rate of 19 h(-1) corresponding to a hydraulic retention time of 3.16 min. Steady state conversion was observed to be about 10% higher at pH 2.3 than that at pH 1.5. Increasing the flowrate of the inlet wastewater caused a reduction in conversion rate. The oxidation rate reduced along the reactor height as the wastewater moved towards the exit at the top but conversion showed the opposite trend. Increasing Fe(2+) concentration up to a critical point resulted in an increased oxidation rate but beyond the critical point caused the oxidation rate to decrease. Luffa cylindrica displayed suitable characteristics for use as a support matrix for formation of a Thiobacillus ferrooxidans biofilm and showed promising potential as an ecological and sustainable alternative to existing synthetic support materials. Membrane separation was shown to be a very effective means of Fe(3+) removal from the wastewater with removal changing from 92% at pH 2.3 to complete removal at pH 5.0. (C) 2003 Society of Chemical Industry.
BibTeX:
@article{Pekdemir2003,
  author = {Pekdemir, T. and Keskinler, B. and Yildiz, E. and Akay, G.},
  title = {Process intensification in wastewater treatment: ferrous iron removal by a sustainable membrane bioreactor system},
  journal = {Journal of Chemical Technology and Biotechnology},
  year = {2003},
  volume = {78},
  number = {7},
  pages = {773--780},
  url = {://WOS:000183935500006},
  doi = {10.1002/jctb.855}
}
Yildiz E, Nuhoglu A, Keskinler B, Akay G and Farizoglu B (2003), "Water softening in a crossflow membrane reactor", Desalination. Vol. 159(2), pp. 139-152.
Abstract: This paper presents an investigation on the removal of hardness by using a crossflow membrane reactor. Lime soda (LS) and caustic soda (CS) were added to hard water as softening chemical agents. The effect of the LS-CS dosage, specific cake resistances (alpha) and transmembrane pressure drop (DeltaP) on steady-state rejection and flux was investigated. Also, flux declines were evaluated with respect to various flux decline models. It was found that hardness rejections decrease for LS and increase for CS with increasing LS and CS dosage, respectively. As DeltaP increases, it was observed that while steady-state fluxes rise for both additives, hardness rejections were decreased for CS and remained constant for LS. A maximum of 97.5% hardness removal was achieved for 100% stochiometric dosages of CS. Obtained steady-state flux values varied between 224 to 881 L/m(2) h, depending on added chemical dosages and applied DeltaP. It was determined that the reason for the flux decline at the beginning of the filtration (i.e., in the rapid flux decline period, RPD) was due to an intermediate pore blocking mechanism. As filtration progressed to the slow flux decline period (SDP), it was concluded that cake filtration occurred for all experiments. If solid matter concentration in the feed solution and applied DeltaP are relatively low, the experiments showed that flux decline is due to the intermediate pore blocking mechanism. However, it was determined that if solid matter concentration in the feed solution and applied DeltaP are relatively high, the flux decline model fits well with the cake filtration model.
BibTeX:
@article{Yildiz2003,
  author = {Yildiz, E. and Nuhoglu, A. and Keskinler, B. and Akay, G. and Farizoglu, B.},
  title = {Water softening in a crossflow membrane reactor},
  journal = {Desalination},
  year = {2003},
  volume = {159},
  number = {2},
  pages = {139--152},
  url = {://WOS:000186381000004},
  doi = {10.1016/s0011-9164(03)90066-x}
}
Zedef V, Matsuda Y, Tanaka Y, Harada H, Oncel MS, Doyen A, Sogut AR and Sensogut C (2003), "Causes of darkening of the pamukkale travertines, Denizli, south-west Turkey", Fresenius Environmental Bulletin. Vol. 12(11), pp. 1373-1378.
Abstract: Since the beginning of the 1990's, the travertines at Pamukkale, south-west Turkey, have faced a serious environmental pollution problem. The travertines were originally snow-white in colour, but this colour has been turning into pale grey. In addition to other features, the snow-white colour and the huge mass of rocks on the edge of Pamukkale plateau make the travertines unique and attractive to visitors. Living bacteria exist 1-2 mm beneath the surface of the travertines in both terrace and water channel types. The thickness of the bacterial lamina is 1-2 mm in the water channel type, whilst it is approximately 1 cm for other types. Absorbance Spectral (AS) data shows that the living bacteria are cyanobacteria, which are responsible for the green colour in certain areas of the travertines. Our investigations show that the major force responsible for the change of colour in the area is the increasing level of excess organic matter, which also causes a shift in the metal content of the travertines. While the greyish polluted samples have 584 ppm of Total Organic Carbon (TOC), the unpolluted snow-white samples have only 177 ppm of TOC. On the other hand, the Al, Fe and Mn contents of the polluted samples are respectively 144, 62, 6 ppm higher than the unpolluted samples. As the TOC is the main cause of the pollution, decreasing the organic matter in the pools would be the first step to protecting the area. This requires limiting, or even banning, people who enter the pools for swimming. Sources of Al, Fe, Mn and other hazardous metals should be reduced in the region.
BibTeX:
@article{Zedef2003,
  author = {Zedef, V. and Matsuda, Y. and Tanaka, Y. and Harada, H. and Oncel, M. S. and Doyen, A. and Sogut, A. R. and Sensogut, C.},
  title = {Causes of darkening of the pamukkale travertines, Denizli, south-west Turkey},
  journal = {Fresenius Environmental Bulletin},
  year = {2003},
  volume = {12},
  number = {11},
  pages = {1373--1378},
  url = {://WOS:000186886900014}
}
Akkoyunlu A, Karpuzcu M, Erturk F and Bayhan H (2002), "The pollution status and environmental effects of Izmit bay (Marmara Sea, Turkey) crossing via tube tunnel or bridge", Fresenius Environmental Bulletin. Vol. 11(11), pp. 957-964.
Abstract: In Turkey, as a developing country, the environmental pollution problems have particularly increased since 1960, due to the rapid growth of industry and widespread increase of population in Marmara region, specifically in the Izmit bay. Since the 1960s, more than 250 large industrial plants have been built in the area surrounding the bay. In addition to the land and atmosphere, the bay is receiving the majority of these wastes. The pollution of Izmit bay has caused great concern to local and national authorities. In this study, environmental impact assessments of the two alternatives, crossing the bay via tunnel or bridge, have been investigated. Measurement of oceanographic parameters shows the presence of a two-layer water body with seasonal variation in the bay. At project route surface concentrations of dissolved oxygen were found to be at their saturation values, whereas they drop down to 0.7 mg/l at the bottom. Polychaeta, species in the deep sludge characterized a retarding ecological system. The fauna species, observed in the benthic structure, would again be recovered after development the crossing via tube or bridge. The dredged material obtained from the bay crossing route can be used in sanitary land filling sites of Gebze. The most inconvenient conditions in terms of air pollution seemed to be caused by tube crossing the bay.
BibTeX:
@article{Akkoyunlu2002,
  author = {Akkoyunlu, A. and Karpuzcu, M. and Erturk, F. and Bayhan, H.},
  title = {The pollution status and environmental effects of Izmit bay (Marmara Sea, Turkey) crossing via tube tunnel or bridge},
  journal = {Fresenius Environmental Bulletin},
  year = {2002},
  volume = {11},
  number = {11},
  pages = {957--964},
  url = {://WOS:000180122100002}
}
Demirbas E, Kobya M, Oncel S and Sencan S (2002), "Removal of Ni(II) from aqueous solution by adsorption onto hazelnut shell activated carbon: equilibrium studies", Bioresource Technology. Vol. 84(3), pp. 291-293.
Abstract: Activated carbon prepared from hazelnut shell was used as an adsorbent for the removal of Ni(II) from aqueous solution. Batch mode adsorption studies were carried out by varying initial metal ion concentration, agitation speed, temperature and particle size. A contact time of 180 min was required to reach equilibrium. The equilibrium data were analysed using the Langmuir, Freundlich and Temkin isotherms. The characteristic parameters for each isotherm were determined. The Langmuir isotherm provided the best correlation for Ni(II) onto the activated carbon. Thermodynamical parameters revealed that the adsorption of Ni(II) is exothermic in nature. (C) 2002 Elsevier Science Ltd. All rights reserved.
BibTeX:
@article{Demirbas2002,
  author = {Demirbas, E. and Kobya, M. and Oncel, S. and Sencan, S.},
  title = {Removal of Ni(II) from aqueous solution by adsorption onto hazelnut shell activated carbon: equilibrium studies},
  journal = {Bioresource Technology},
  year = {2002},
  volume = {84},
  number = {3},
  pages = {291--293},
  url = {://WOS:000176419800015},
  doi = {10.1016/s0960-8524(02)00052-4}
}
Karpuzcu M, Dimogio A and Akbulut HY (2002), "Purification of agro-industrial wastewater from the grease-protein mixture by means of electroflotocoagulation", Water Science and Technology. Vol. 45(12), pp. 233-240.
Abstract: The process of agro-industrial sewage treatment with the aim of extracting grease from the waters is studied by means of electroflotocoagulation. A method of optimising the construction of electroflotocoagulation apparatus for sewage treatment is offered that allows passing from a laboratorial model to an industrial specimen that possesses the same level of technological characteristics, Multiple examples are given of applying electroflotocoagulation technology for sewage treatment from proteins and grease under different conditions.
BibTeX:
@article{Karpuzcu2002,
  author = {Karpuzcu, M. and Dimogio, A. and Akbulut, H. Y.},
  title = {Purification of agro-industrial wastewater from the grease-protein mixture by means of electroflotocoagulation},
  journal = {Water Science and Technology},
  year = {2002},
  volume = {45},
  number = {12},
  pages = {233--240},
  url = {://WOS:000177805700029}
}
Kobya M, Demirbas E, Oncel MS and Sencan S (2002), "Adsorption kinetic models applied to nickel ions on hazelnut shell activated carbons", Adsorption Science & Technology. Vol. 20(2), pp. 179-188.
Abstract: Kinetic models describing the adsorption of Ni(II) ions on to hazelnut shell active carbon (HSAC) have been compared. Kinetic studies have also been carried out in a batch adsorber over a range of initial metal ion concentration (11.87-92.34 mg/dm(3)), agitation speed (50-200 rpm) and adsorbent particle size (0.90-1.60 mm). The rate models evaluated included the pseudo-first order equation, the pseudo-second order equation and the Elovich equation, The results obtained showed that the pseudo-second order kinetic model correlated the experimental data well and better than the other models examined in this study.
BibTeX:
@article{Kobya2002,
  author = {Kobya, M. and Demirbas, E. and Oncel, M. S. and Sencan, S.},
  title = {Adsorption kinetic models applied to nickel ions on hazelnut shell activated carbons},
  journal = {Adsorption Science & Technology},
  year = {2002},
  volume = {20},
  number = {2},
  pages = {179--188},
  url = {://WOS:000178022900007}
}
Yildirim Y, Demircioglu N, Kobya M and Bayramoglu M (2002), "A mathematical modeling of sulphur dioxide pollution in Erzurum City", Environmental Pollution. Vol. 118(3), pp. 411-417.
Abstract: A non-linear simple air-quality model was developed by applying the continuity equation for the air control volume over Erzurum city center and tested using daily average values Of SO2 and meteorological data obtained during the winter seasons in Erzurum, Turkey from 1994 to 1998. Model parameters are estimated by non-linear regression analysis. Agreement between model predictions and measured data was found very satisfactory with standard deviations less than 20 mug/m(3). (C) 2002 Elsevier Science Ltd. All rights reserved.
BibTeX:
@article{Yildirim2002,
  author = {Yildirim, Y. and Demircioglu, N. and Kobya, M. and Bayramoglu, M.},
  title = {A mathematical modeling of sulphur dioxide pollution in Erzurum City},
  journal = {Environmental Pollution},
  year = {2002},
  volume = {118},
  number = {3},
  pages = {411--417},
  url = {://WOS:000175229700015},
  doi = {10.1016/s0269-7491(01)00291-3}
}
Celen I and Turker M (2001), "Recovery of ammonia as struvite from anaerobic digester effluents", Environmental Technology. Vol. 22(11), pp. 1263-1272.
Abstract: The effects of environmental conditions on ammonia removal as struvite (Magnesium ammonium phosphate, MAP) were studied in a laboratory scale batch reactor. MAP precipitation was carried out by adding phosphoric acid and magnesium source either as MgCl2 or MgO. The effect of temperature, pH, Mg:N:P ratios were studied. Temperature did not significantly affect ammonia removal between 25-40 degreesC and over 90% removal was obtained. The effect of pH, however, was significant and highest removal was reached at pH 8.5-9.0. The various stoichiometric ratios of ammonium to Mg and P have been tested and slight excess of Mg and P found to be beneficial for higher recovery of ammonia as struvite. However further increase in Mg and P ratios did not result in further ammonia removal which is also costly for the practical application of the process. When MgO was used as M source, the ammonia recovery was 60-70% whereas the use of MgCl2 has increased this figure up to 95%. In addition a two step purification process was developed to recover MAP crystals from impurities of the anaerobic digester. Firstly, precipitates were dissolved in acid and impurities were removed by centrifugation. The clarified supernatant was re-precipitated by adjusting its pH with caustic. It was shown that in the two steps process white MAP crystals could be obtained with over 85% recovery to be used for another applications. The economical analysis of the process has shown that ammonia in the digester effluents can be recovered at the cost of $7.5-8.0 kg(-1) NH4+-N. The rate of reaction is very fast and is completed almost in minutes. This simplifies the process design resulting in a smaller reaction vessel.
BibTeX:
@article{Celen2001,
  author = {Celen, I. and Turker, M.},
  title = {Recovery of ammonia as struvite from anaerobic digester effluents},
  journal = {Environmental Technology},
  year = {2001},
  volume = {22},
  number = {11},
  pages = {1263--1272},
  url = {://WOS:000173007400003},
  doi = {10.1080/09593332208618192}
}
Dogan O, Simsek O, Ertugrul M and Kobya M (2001), "X-ray fluorescence spectrometry analysis of trace elements in fly ash samples of Yenikoy Thermal Power Plants", Instrumentation Science & Technology. Vol. 29(5), pp. 433-439.
Abstract: Fly ash samples collected by means of an electrostatic precipitator from the lignite-fired Yenikoy Power Plants located in Turkey were analysed using an x-ray fluorescence (XRF) technique. Five trace elements, namely Nd, Ba, Mo, Sr, and As, were quantified using XRF The concentrations of these elements can be helpful in developing an environmental pollution abatement approach for various applications of fly ash, such as cement manufacture, wastewater treatment, light-weight contraction aggregate, ceramic production, and as a secondary source in recovery of valuable elements.
BibTeX:
@article{Dogan2001,
  author = {Dogan, O. and Simsek, O. and Ertugrul, M. and Kobya, M.},
  title = {X-ray fluorescence spectrometry analysis of trace elements in fly ash samples of Yenikoy Thermal Power Plants},
  journal = {Instrumentation Science & Technology},
  year = {2001},
  volume = {29},
  number = {5},
  pages = {433--439},
  url = {://WOS:000171932000008},
  doi = {10.1081/ci-100107235}
}
Kirisits MJ, Snoeyink VL, Inan H, Chee-Sanford JC, Raskin L and Brown JC (2001), "Water quality factors affecting bromate reduction in biologically active carbon filters", Water Research. Vol. 35(4), pp. 891-900.
Abstract: Biological removal of the ozonation by-product, bromate, was demonstrated in biologically active carbon (BAC) filters. For example, with a 20-min EBCT, pH 7.5, and influent dissolved oxygen (DO) and nitrate concentrations 2.1 and 5.1 mg/l, respectively, 40% bromate removal was obtained with a 20 mug/l influent bromate concentration. In this study, DO, nitrate and sulfate concentrations, pH, and type of source water were evaluated for their effect on bromate removal in a BAC filter. Bromate removal decreased as the influent concentrations of DO and nitrate increased, but bromate removal was observed in the presence of measurable effluent concentrations of DO and nitrate. In contrast, bromate removal was not sensitive to the influent sulfate concentration, with only a slight reduction in bromate removal as the influent sulfate concentration was increased from 11.1 to 102.7 mg/l. Bromate reduction was better at lower pH values (6.8 and 7.2) than at higher pH values (7.5 and 8.2), suggesting that it may be possible to reduce bromate formation during ozonation and increase biological bromate reduction through pH control. Biological bromate removal in Lake Michigan water was very poor as compared to that in tapwater from a groundwater source. Bromate removal improved when sufficient organic electron donor was added to remove the nitrate and DO present in the Lake Michigan water, indicating that the poor biodegradability of the natural organic matter may have been limiting bromate removal in that water. Biological bromate removal was demonstrated to be a sustainable process under a variety of water quality conditions, and bromate removal can be improved by controlling key water quality parameters. (C) 2001 Elsevier Science Ltd. All rights reserved.
BibTeX:
@article{Kirisits2001,
  author = {Kirisits, M. J. and Snoeyink, V. L. and Inan, H. and Chee-Sanford, J. C. and Raskin, L. and Brown, J. C.},
  title = {Water quality factors affecting bromate reduction in biologically active carbon filters},
  journal = {Water Research},
  year = {2001},
  volume = {35},
  number = {4},
  pages = {891--900},
  url = {://WOS:000167033400005},
  doi = {10.1016/s0043-1354(00)00334-1}
}
Yatmaz HC, Wallis C and Howarth CR (2001), "The spinning disc reactor - studies on a novel TiO2 photocatalytic reactor", Chemosphere. Vol. 42(4), pp. 397-403.
Abstract: A new type of photocatalytic reactor, the spinning disc reactor (SDR), was used to degrade aqueous solutions of 4-chlorophenol and salicylic acid. The efficiency of the photocatalytic process depends on the type of UV source used. Lamps supplying shorter wavelength UV radiation are more efficient than those whose emissions lay mainly in the near UV region. The method used to coat the disc of the SDR does not meet its operational requirements. The characteristics of the turbulent liquid films produced in the SDR reduce the influence of mass transfer over the overall photocatalytic process. (C) 2000 Elsevier Science Ltd. All rights reserved.
BibTeX:
@article{Yatmaz2001,
  author = {Yatmaz, H. C. and Wallis, C. and Howarth, C. R.},
  title = {The spinning disc reactor - studies on a novel TiO2 photocatalytic reactor},
  journal = {Chemosphere},
  year = {2001},
  volume = {42},
  number = {4},
  pages = {397--403},
  url = {://WOS:000165351800009},
  doi = {10.1016/s0045-6535(00)00088-6}
}
Demircioglu N, Levent M, Kobya M and Topcu N (2000), "The effects of stirring speed on coupled transport of nitrite ions through liquid membranes", Chemical and Biochemical Engineering Quarterly. Vol. 14(4), pp. 109-116.
Abstract: In this study, the appeals of stirring speed on coupled transport of nitrite ions through liquid membranes has been investigated at various stirring speeds in the range of 100-250 rpm. Coupled transport of nitrite ions through liquid membranes (cp = 85 % hexane + phi = 15 % trichlorometane) containing tetraoctyl ammonium chloride (TOACl) as a carrier, was examined. For the diffusion of the nitrite ion-carrier complex at various stirring speeds through the narrow boundary layers at the interface of the membrane, the variable membrane entrance (k(1d) and exit rates (k(2m) and k(2a)) are the rate determining steps. The activation energies of membrane entrance and exit permeate rates for nitrite ions are E-am = 1.58 and E-aa = 1.583 kJ mol(-1), respectively. From these experimental results, it was concluded that the reaction was diffusion controlled. The membrane was stable during the transport experiments (no leakage of carrier and carrier-nitrite ion complexes to both aqueous phases and also there was no supplementary water penetration into the membrane was observed). This favours the interfacial character of nitrite ion-carrier complexion reaction.
BibTeX:
@article{Demircioglu2000,
  author = {Demircioglu, N. and Levent, M. and Kobya, M. and Topcu, N.},
  title = {The effects of stirring speed on coupled transport of nitrite ions through liquid membranes},
  journal = {Chemical and Biochemical Engineering Quarterly},
  year = {2000},
  volume = {14},
  number = {4},
  pages = {109--116},
  url = {://WOS:000166433700001}
}
Demircioglu N, Levent M, Kobya M and Topcu N (2000), "Kinetic analysis of coupled transport of nitrite ions through liquid membranes at different temperatures", Filtration & Separation. Vol. 37(3), pp. 51-56.
Abstract: Non-steady state kinetics of the coupled transport of nitrite (NO2-) ions through liquid membranes (n-hexane 85% + chloroform 15%) containing tetraoctylammonium chloride as a carrier was examined at temperatures ranging from 273-308 degrees K. In this study, the, influence of temperature on the kinetic parameters (k(1d), k(2m), k(2a), t(max), R-m(max), J(d)(max), J(a)(max)) was investigated. The membrane entrance (k(1d)) and exit rates (k(2m), k(2a)) were increased with temperature. For maximum membranes entrance and exit fluxes, the activation energies were calculated from the slopes of the two linear relationships: E-ad = 6.62 kcal/mol and E-aa = 6.63 kcal/mol, respectively. The values of the calculated activation energy indicate that the process is diffusionally controlled.
BibTeX:
@article{Demircioglu2000a,
  author = {Demircioglu, N. and Levent, M. and Kobya, M. and Topcu, N.},
  title = {Kinetic analysis of coupled transport of nitrite ions through liquid membranes at different temperatures},
  journal = {Filtration & Separation},
  year = {2000},
  volume = {37},
  number = {3},
  pages = {51--56},
  url = {://WOS:000086488300007},
  doi = {10.1016/s0015-1882(00)88505-5}
}