Ugur Kurt

Optimization of energy costs in the pretreatment of olive mill wastewaters by electrocoagulation

In this study, the electrocoagulation process was evaluated as a pretreatment process for olive mill wastewaters. Aluminium (Al) and iron (Fe) electrodes, several contact times and 0.5, 1 and 2 A currents were used to compare chemical oxygen demand (COD) removal efficiencies for each case. The optimum contact time and current were 45 minutes and 1 A, respectively, which resulted in a COD removal of 58.7% with an Al electrode. Experimental data from distinct operational conditions were used to fit a model for COD removal efficiencies. Energy consumption was also predicted. Under optimum operational conditions, the treatment cost was approximately €0.13 kg−1 CODremoved and €4.41 m−3. The results showed that the electrocoagulation process was a cost-effective method for the pretreatment of olive mill wastewaters.

Fuzzy-logic modeling of Fenton’s strong chemical oxidation process treating three types of landfill leachates

Three multiple input and multiple output-type fuzzy-logic-based models were developed as an artificial intelligence-based approach to model a novel integrated process (UF–IER–EDBM–FO) consisted of ultrafiltration (UF), ion exchange resins (IER), electrodialysis with bipolar membrane (EDBM), and Fenton’s oxidation (FO) units treating young, middle-aged, and stabilized landfill leachates. The FO unit was considered as the key process for implementation of the proposed modeling scheme. Four input components such as H2O2/chemical oxygen demand ratio, H2O2/Fe2+ ratio, reaction pH, and reaction time were fuzzified in a Mamdani-type fuzzy inference system to predict the removal efficiencies of chemical oxygen demand, total organic carbon, color, and ammonia nitrogen. A total of 200 rules in the IF–THEN format were established within the framework of a graphical user interface for each fuzzy-logic model. The product (prod) and the center of gravity (centroid) methods were performed as the inference operator and defuzzification methods, respectively, for the proposed prognostic models. Fuzzy-logic predicted results were compared to the outputs of multiple regression models by means of various descriptive statistical indicators, and the proposed methodology was tested against the experimental data. The testing results clearly revealed that the proposed prognostic models showed a superior predictive performance with very high determination coefficients (R2) between 0.930 and 0.991. This study indicated a simple means of modeling and potential of a knowledge-based approach for capturing complicated inter-relationships in a highly non-linear problem. Clearly, it was shown that the proposed prognostic models provided a well-suited and cost-effective method to predict removal efficiencies of wastewater parameters prior to discharge to receiving streams.

Hydrogen Gas Production from Tannery Wastewater by Electrocoagulation of a Continuous Mode with Simultaneous Pollutants Removal

The performance of a continuous electrocoagulation (EC) process was investigated for tannery wastewater treatment using aluminum and iron electrodes. The effects of the operating parameters, such as current density, pH of solution and inlet flow rate, on pollutants removal efficiency and recovery of hydrogen gas were investigated in order to optimize process performance. In the case of aluminum electrodes, The results showed that for tannery wastewater with an influent pH adjusted at about 6, the use of a current density of 14 mA/cm 2 , and an EC time of 125 min, gave access to pollutants (COD, Color, Cr, and NH3-N) removal efficiency 73, 94, 100 and 51%, respectively. The energy yield of harvested hydrogen was 16% of the electrical energy demand of the electrocoagulation process. However, in the case of iron electrodes, with effluent pH adjusted at about 7, , the use of a current density of 14 mA/cm 2 , and an EC time of 125 min, gave access to pollutants (COD, Color, Cr, and NH3-N) removal efficiency 67, 93, 100 and 46 %, respectively. And also, the energy yield of harvested hydrogen was 15 % of the electrical energy demand of the electrocoagulation process. Thus, the operating costs for two cases were found to be 0.675

Optimization of treatment leachates from young, middle-aged and elderly landfills with bipolar membrane electrodialysis

/m 3 wastewater. It could be seen that hydrogen gas production coupled with pollutants removal efficiency by EC continuous mode would be an effective approach for energy recovery and wastewater reutilization.

Treatment of leachate by electrocoagulation using aluminum and iron electrodes

ABSTRACT In this study, a bipolar membrane electrodialysis (BMED) process, which is thought to be an effective treatment method for leachate, was evaluated for leachates of three different ages (‘young’, ‘middle-aged’ and ‘elderly’). The leachates were pretreated to eliminate membrane fouling problems prior to the BMED process. Experimental studies were carried out to determine optimal operating conditions for the three differently aged leachates in the BMED process. According to the experiment results, there was a high removal efficiency of conductivity determined at 4 membrane – 25 V for young and elderly leachate and at 1 membrane – 25 V for middle-aged leachate. It was found that the operating times required to reach the optimal endpoints (at conductivity of about 2 mS/cm) of BMED process were 90, 180 and 300 min for the middle-aged, young and elderly leachates, respectively. Under the optimum operating conditions for the BMED process, removal efficiencies of conductivity and chemical oxygen demand were determined to be 89.5% and 60% for young, 82.5% and 30% for middle-aged and 91.8% and 26% for elderly leachate, respectively.