Investigation of advanced treatment of brewery wastewater by electrocoagulation method

In this thesis, the advanced treatment of brewery wastewater through the electrocoagulation method using aluminum and stainless-steel electrodes was investigated. Optimization studies were conducted for different configurations of the electrodes, and the optimum operating time, initial pH, and current density for each configuration were determined based on chemical oxygen demand (COD) removal efficiencies. In the experiments, the operating times were selected in the range of 10-60 minutes (10, 20, 30, 40, 50, 60), the pH range was set between 4-9 (4, 5, 6, 7, 8, 9), and the current density was adjusted between 25-100 A/m2 (25, 50, 75, 100). These parameters were optimized for each electrode configuration. The optimization results showed that the optimum conditions for the aluminum-stainless steel electrode pair were an operating time of 30 minutes, an initial pH of 4, a current density of 100 A/m2, and a COD removal efficiency of 81.5%. For the stainless steel-stainless steel electrode pair, the optimum conditions were determined as 50 minutes, pH 6, 100 A/m², and 95.43% COD removal efficiency. For the aluminum-aluminum electrode pair, optimal conditions were determined as 30 minute operating time, initial pH 5, current density 100 A/m², and COD removal efficiency 81.15%, while for the stainless steel-aluminum electrode pair, optimal conditions were identified as 40-minute operating time, initial pH 5, current density 75 A/m², and approximately 96% COD removal efficiency. The results revealed that the stainless steel-aluminum and stainless steel-stainless steel electrode configurations were achieved the highest COD removal efficiencies, 96% and 95.43%, respectively. The removal efficiencies of the total suspended solids (TSS), color, and turbidity for the stainless steel-aluminum electrode configuration (TSS 65.52%, colour 78.56%, turbidity 90%) were higher than that for the stainless steel-stainless steel electrode configuration ( TSS 48.28% , color 54.51% , and turbidity 64% ). Furthermore, energy consumption evaluations showed that the treatment of 1 m3 of wastewater required 5.7 kWh of energy for the stainless steel-aluminum electrode pair and 11.83 kWh for the stainless steel-stainless steel electrode pair.