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Öğe Determination of inert chemical oxygen demand (COD) fractions of Cumhuriyet University wastewater(UNIV AEGEAN, 2005) Ciner, Fehiman; Cebeci, Meltem Sarioglu; Lekkas, TDSome amounts of inert products are given into environment due to biological degradation of substrate in activated sludge system. The effluent of biological wastewater treatment consists of inert substrate in influent flow, soluble microbial products and non degradable or slowly degradable organic products. Soluble inert COD (SI) must be determined for discharge standards since it did not give any reaction in activated sludge system and was given with wastewater discharge. However particular inert COD (XI) accumulated in system depending on sludge retention time due to it is only wasted from system by wasted sludge. In this study, in order to determine inert COD fractions in Cumhuriyet University campus wastewater, three aerobic batch reactor systems were used. At the end of approximately 381 h operation, COD composition of campus wastewater were found to be C-T0=372 mgl(-1), X-S0=56 mgl(-1), S-S0=104 mgl(-1), C-S0=149 mgl(-1), S-I=12 mgl(-1), X-I=211 mgl(-1), respectively.Öğe Investigation of the removal of color and heavy metal from wastewater using activated sludge continuous system and application of models(Elsevier, 2024) Cebeci, Meltem Sarioglu; Guler, Ulker AsliIn the continuous system studies, the natural state of the activated sludge was used in the fixed bed column and fluidized bed column, and the studies were carried out with the synthetic solution wastewater similar to the metal coating industry. Experiments at operating conditions of bed heights 20 cm, initial Cu2+, Ni2+, and Methylene Blue concentrations of 100 mg/L, pH 5.0 and flow rates 2 mL/min were performed to study the performance of the fixed bed column and fluidized bed column. It is seen that the removal efficiencies of the fixed bed and fluidized bed column are very close to each other. Thomas, Yoon-Nelson and Bohart-Adams models were applied to the data obtained in the fixed bed column system. It has been observed that there is a good agreement between the experimental breakthrough curves and the model predictions. In addition, regeneration of activated sludge with 0.1 M HCl and a reuse experiments were carried out, and it was observed that the efficiency decreased considerably in the second use. The results are promising and shall serve to design the activated sludge based fixed bed column and fluidized bed column to obtain cleaner and sustainable treatment of industrial wastewaters containing Cu, Ni and Methylene Blue.Öğe Investigation of the treatability of molasses and industrial oily wastewater mixture by an anaerobic membrane hybrid system(ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2018) Cebeci, Meltem Sarioglu; Gokcek, Oznur BegumIn this study, the anaerobic treatability of automotive industry wastewater and its treatment in the subsequent membrane system were examined by using molasses, which is a waste of the sugar industry, as a co-substrate. Organic loadings of 3-3, 5-4, and 5gCOD/L/day were applied to a UASB reactor made of steel with a working volume of 7 L. The hydraulic retention time (HRT) was kept constant at 2 days. Temperature, pH, COD, alkalinity, Volatile Fatty acid (VFA) and biogas were monitored. The best COD removal was achieved at the value of 4 gCOD/L/day. The average COD removal rate was 77%. The effluent from the UASB reactor was transferred to the membrane system. The flux reductions of the PW10 kDa UF membrane at different concentrations were 1.717 gCOD/L, 1.934 gCOD/L, 2.257 gCOD/L, 4 gCOD/L, and 8 gCOD/L, and they were 90.78%, 42.69%, 45.88%, 51.00%, and 56.60%, respectively, at the input concentrations. The flux reductions of the UE50 100 kDa UF membrane at the input concentrations of 4 gCOD/L and 8 gCOD/L were 76.00% and 66.25%, respectively. It was determined that the UE50 100 kDa membrane caused more fouling compared to the PW 10 kDa UF membrane. Pore fouling models were determined for the flux reduction in the membranes and the mechanism behind it. Heavy metal and organic matter removals were examined in the effluent obtained from the membrane experiments.Öğe Optimization of photocatalytic treatment parameters by response surface method in dye removal with TiO 2-ZrO 2 catalyst(Pamukkale Univ, 2023) Selcuk, Sefa Furkan; Koker, Berk; Cebeci, Meltem SariogluFor the optimization of chemical processes, traditional methods by accepting one parameter as variable and keeping other parameters constant are insufficient. Methods that allow the interaction of parameters by modeling the process, such as the response surface method, provide both financial and temporal advantages. In this study, response surface method and central composite design were used to model and optimize the removal parameters of Maxilon Blue GRL dye by photocatalytic method. The catalyst concentration, the amount of ZrO 2 used in the production of the catalyst and the reaction time were selected as removal parameters. As a response parameter, the color removal efficiency was investigated. In the single factor analysis, optimum conditions were determined as 0.775g/L catalyst, 0.4g ZrO 2 amount and 45min reaction time. With the analysis of 3D surface and contour graphics, it was evaluated that the interaction between catalyst concentration and ZrO 2 amount parameters was low, while the interaction of the reaction time parameter with the ZrO 2 amount and catalyst concentration parameters was found to be high. In line with the results of the ANOVA analysis and validation experiment, it has been proven that the predicted values of the model can represent the analysis values. In the optimum option chosen for the validation experiment, the estimated value of the model was 90.154%, while 91% removal efficiency was achieved as a result of the analysis.Öğe Potential of pumice modified with iron(III) for copper removal from aqueous solutions(Wroclaw University of Science and Technology, 2017) Guler, Ulker Asli; Cebeci, Meltem SariogluIron-modified pumice (Fe-P) was prepared by the ion-exchange method using natural pumice from Kayseri, Turkey at room temperature without calcination. SEM, FTIR, XRD, and SBET measurement were used to investigate the copper removal mechanism. The results show that the SBET of the pumice increased from 11.88 m2/g to 21.01 m2/g after iron modification. The effects of pH, contact time, initial copper concentration, temperature, and various cations (Na+, K+, Ca2+, Mg2+ and Al3+) at various pH were investigated in batch experiments. More than 92% of Cu(II) was removed after 180 min. Langmuir, Freundlich, Dubinin–Radushkevich and Temkin isotherm models were applied to the equilibrium data at 298, 308 and 318 K. The maximum adsorption capacity at 298, 308 and 318 K was found to be 21.52, 19.48, and 19.67 mg/g, respectively. The kinetics of copper on Fe-P was best described by the pseudo-second order kinetic model. The negative values of free energy change and enthalpy change indicated that the adsorption process was feasible, spontaneous and exothermic. © 2017 Technical University of Wroclaw. All rights reserved.Öğe POTENTIAL OF PUMICE MODIFIED WITH IRON(III) FOR COPPER REMOVAL FROM AQUEOUS SOLUTIONS(TECHNICAL UNIV WROCLAW, 2017) Guleri, Ulker Asli; Cebeci, Meltem SariogluIron-modified pumice (Fe-P) was prepared by the ion-exchange method using natural pumice from Kayseri, Turkey at room temperature without calcination. SEM, FTIR, XRD, and S-BET measurement were used to investigate the copper removal mechanism. The results show that the SBET of the pumice increased from 11.88 m(2)/g to 21.01 m(2)/g after iron modification. The effects of pH, contact time, initial copper concentration, temperature, and various cations (Na+, K+, Ca2+, Mg2+ and Al3+) at various pH were investigated in batch experiments. More than 92% of Cu(II) was removed after 180 min. Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherm models were applied to the equilibrium data at 298, 308 and 318 K. The maximum adsorption capacity at 298, 308 and 318 K was found to be 21.52, 19.48, and 19.67 mg/g, respectively. The kinetics of copper on Fe-P was best described by the pseudo-second order kinetic model. The negative values of free energy change and enthalpy change indicated that the adsorption process was feasible, spontaneous and exothermic.Öğe Projections of meteorological drought events in the upper Kızılırmak basin under climate change scenarios(Springer Wien, 2024) Selcuk, Sefa Furkan; Selcuk, Burcu Circi; Cebeci, Meltem SariogluClimate change, whose negative impacts are becoming increasingly apparent as a result of human actions, intensifies the drought problems to dangerous levels. The development of local-scale drought projections is crucial to take necessary precautions for potential risks and possible effects of drought. In this study, drought analysis was conducted in the Upper K & imath;z & imath;l & imath;rmak Basin using the standard precipitation index (SPI) method for the near future (2020-2049), mid-century (2050-2074), and late century (2075-2099). The precipitation data required for the SPI were gathered from the data sets developed for the SSP climate change scenarios of the four chosen global climate models. Precipitation data has been made more convenient for local analysis studies with the statistical downscaling method. Forecasts have been created for the temporal variation and spatial distribution of drought events. The study findings indicate that, under the SSP 2-4.5 scenario, drought-related effects of climate change will decrease until 2100. On the other hand, the number and severity of drought events, as well as the duration of dry periods, will increase until 2100 under the SSP 5-8.5 scenario. According to the SSP 5-8.5 scenario, consisting of the most pessimistic forecasts, moderate drought will last 0-60 months, severe drought will last 0-30 months, and extreme drought will last 0-20 months in different regions of the area in the late century. The spatial distribution of droughts will differ based on the SPI index and climate change scenarios. Comparison of SPI and CZI data showed that both indices are effective in meteorological drought analyses.Öğe RESPONSE SURFACE MODELLING FOR REACTIVE DYE REMOVAL USING BIO-SOLIDS: APPLICATION OF BOX-BEHNKEN EXPERIMENTAL DESIGN(Parlar Scientific Publications (P S P), 2015) Cebeci, Meltem Sarioglu; Gokcek, Oznur BegumThe removal of reactive dyes is rather difficult by chemical coagulation/flocculation because of strong resistance to biodegradation in aerobic environments. The removal of color from textile wastewater using low-cost adsorbents instead of expensive adsorbents is considered to be an important application of adsorption. In this study, powder-activated sludge was studied for the removal of color from aqueous solutions in a batch system using response surface methodology. Effects of initial pH, initial reactive dye concentration (Everzol Yellow 3RS H/C), contact time, and amount of bio-solid dosage (dried activated sludge) was optimized by using a four-factor, three-level Box-Behnken design for response surface modeling. Experiments were carried out in a lab-scale batch study. Four independent variables (initial pH: 2-8, initial concentration of dye ions (Co): 25-200 mg/L, contact time (tc): 10-180 min, and bio-solid amount (m): 1-15 g/L) were labeled as A, B, C, and D at three levels (-1, 0, 1), and a second-order polynomial regression equation was used to predict responses. The variables were tested by using analysis of variance (ANOVA). The optimal conditions were found to be pH = 2, Co = 200 mg/L, tc = 95 min, and m = 0.8 g/100 ml for which EY3RS removal was 92.75%. The results show that dye concentrations, bio-solid amount, and contact time are the most important factors in color removal. All factors showed combined effects on dye removal.
