ORCID Profile
0000-0001-8322-1666
Current Organisation
Boğaziçi University
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Publisher: Springer Science and Business Media LLC
Date: 2000
Abstract: The anaerobic treatability and methane generation potential of the wastewaters of the three important agro-industries in Turkey, namely, cheese-making, poultry breeding and the olive-oil mill industries were studied. Biochemical methane potential (BMP) experiments were conducted for different initial chemical oxygen demand (COD) concentrations. The results indicate that anaerobic treatment was possible for all the wastewaters studied and the biogas produced had a high methane content.
Publisher: Elsevier BV
Date: 2001
DOI: 10.1016/S0956-053X(01)00013-7
Abstract: In the pulp and paper industry, lignin and other color compounds are removed by chemical agents in bleaching process. Use of chlorine-based agents results in production of degradation products which include various chloro-organic derivatives. Since these new compounds are highly chlorinated, they cause a problem in the treatment of pulp and paper industry wastewaters. Chemical precipitation, lagooning, activated sludge, and anaerobic treatment are the processes used for treating pulp and paper effluents. Furthermore, a combination of these processes is also applicable. In this study, the effluent of Dalaman SEKA Pulp and Paper Industry was examined for its toxic effects on anaerobic microorganisms by anaerobic toxicity assay. Additionally, this wastewater was applied to a sequential biotreatment process consisting of an upflow anaerobic sludge blanket as the anaerobic stage and a once-through completely mixed stirred tank as the aerobic stage. Results indicated that: (1) Dalaman SEKA Pulp and Paper Industry wastewater exerted no inhibitory effects on the anaerobic cultures under the studied conditions, and (2) application of a sequential biological (anaerobic/aerobic) system to treat the Dalaman SEKA Pulp and Paper Industry wastewater resulted in approximately 91% COD and 58% AOX removals at a HRT of 5 and 6.54 h for anaerobic and aerobic, respectively.
Publisher: Wiley
Date: 10-07-2009
DOI: 10.1002/BIT.22443
Abstract: The denitrification process was incorporated into the IWA Anaerobic Digestion Model No. 1 (ADM1) in order to account for the effect of denitrification on the methanogenic fermentation process. The model was calibrated and optimized using previously published experimental data and kinetic parameter values obtained with a mixed, mesophilic (35 degrees C) methanogenic culture. Model simulations were used to predict the effect of nitrate reduction on the methanogenic fermentation process in batch, semi-continuous, and continuous flow reactors experiencing operational changes and/or system disturbances. The extended model clearly revealed the importance of substrate competition between denitrifiers and non-denitrifiers as well as the impact of N-oxide inhibition on process interactions between fermentation, methanogenesis, and denitrification.
Publisher: Elsevier BV
Date: 2001
DOI: 10.1016/S0956-053X(00)00114-8
Abstract: Anaerobic treatability and methane generation potential of cheese whey were determined in batch reactors. Furthermore, the effect of nutrient and trace metal supplementation on the batch anaerobic treatment, and the high-rate anaerobic treatability of cheese whey in upflow anaerobic sludge blanket (UASB) reactors were investigated. To this purpose biochemical methane potential experiments were conducted and single- and two-stage UASB reactors with granular cultures were operated. In UASB experiments significance of process staging, operational parameters such as hydraulic retention time (HRT), influent chemical oxygen demand (COD) concentration and loading rate were also investigated. The results revealed that nutrient and trace metal supplementation is vital for the anaerobic treatment of cheese whey the anaerobic methane generation for the cheese whey studied was found to be 424 ml CH4/g COD (23.4 1 CH4/l cheese whey) undiluted cheese whey could be treated anaerobically at relatively short HRT values (2.06-4.95 days) without any significant stability problems HRT values as low as 2-3 days can be used for the anaerobic treatment of cheese whey, with a COD removal efficiency of 95-97% at influent COD concentration of 42 700 +/- 141-55 100 +/- 283 mg/l.
Publisher: IWA Publishing
Date: 08-2006
DOI: 10.2166/WST.2006.524
Abstract: Nitrate reduction processes were incorporated into the IWA Anaerobic Digestion Model No. 1 (ADM1) in order to account for the effect of such processes on fermentation and methanogenesis. The general structure of the ADM1 was not changed except for modifications related to disintegration and hydrolysis of complex organic matter and decayed biomass. A fraction of butyrate/valerate and propionate degraders was assumed to be the fermentative denitrifiers carrying out fermentation in the absence of N-oxides. Nitrate reduction proceeded in a stepwise manner to nitrite, nitric oxide, nitrous oxide and nitrogen gas using four substrates as electron and/or carbon source. The utilization of the four substrates and N-oxides was based on stoichiometry and kinetics. The inhibitory effect of N-oxides on the methanogens was accounted for by the use of non-competitive inhibition functions. Model simulations were compared with experimental data obtained with a batch, mixed fermenting and methanogenic culture amended with various initial nitrate concentrations.
Publisher: Proceedings of the National Academy of Sciences
Date: 14-02-2022
Abstract: Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world's rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. S les were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the s ling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.
No related grants have been discovered for Ulas Tezel.