Colour removal from food industry wastewater by electrochemical process

In this study, the color removal efficiency of the electrooxidation (EO) process from yeast industry biological wastewater treatment plant discharge wastewater using graphite, titanium and stainless steel electrodes and the usability of water obtained after EO process in different processes of the industry were investigated. The effects of operating parameters such as pH, current density and electrolysis time on the removal of color parameters RES 436, RES 525 and RES 620 were determined. In the experimental studies, Box-Behnken statistical model, one of the surface response methods, was used to determine the optimum independent variables. Statistical analysis showed that the model was found to be compatible with the Quadratic model, R2-R2adj values for RES 436, RES 525 and RES 620 were 0,94-0,83, 0,92-0,76 and 0,95-0,85 in EO process using graphite electrodes, in the EO process using titanium electrode, R2 values for RES 436, RES 525 and RES 620 were 0,99-0,97, 0,99-0,97 and 0,98-0,95, respectively; In the EO process using stainless steel electrodes, R2 values for RES 436, RES 525 and RES 620 were determined as 0,99-0,98, 0,97-0,93 and 0,99-0,98, respectively. As a result, it is concluded that R2 values are close to each other, R2 and R2adj values are close to each other and color removal efficiency can be explained by Box-Behnken statistical model. Optimum pH values for the EO process using graphite, titanium and stainless steel electrodes were 4,57, 4,50, 4,84, respectively; current density was determined as 139,84 A / m2, 84,23 A / m2 and 60,15 A / m2 respectively; electrolysis time was determined as 58 min, 43 min and 45 min., respectively. Colour removal efficiencies for graphite, titanium and stainless steel electrodes at optimum conditions were determined as 97% for RES 436, 99,99% for RES 525 and 99,99% for RES 620 respectively; 89% for RES 436, 98% for RES 525 and 99,99% for RES 620; 98% for RES 436, 95% for RES 525, 99,99% for RES 620, respectively. Energy consumption varies between 30-117,86 kWh/m3 / 34,2-122,2 kWh/m3 / 4,64-42,86 kWh/m3 for graphite, titanium and stainless steel electrodes, respectively.