Turbidity removal by electrooxidation from pistachio processing wastewater using ti/pt anodes

Abstract

Turbidity is the presence of suspended substances in water and is a pollution parameter for water. In this study, the removal of turbidity from pistachio processing wastewater by the electrooxidation process was investigated. Ti/Pt was used as the anode material and stainless steel was used as the cathode material. Stirring speed, supporting electrolyte type, and supporting electrolyte type concentration, initial pH value, and current density were investigated as working parameters. The mixing speed was investigated at 0, 200, 400, and 600 rpm. NaCl, KCl, Na2SO4, and NaNO3 were used as supporting electrolyte types. 0, 0.250, 0.500, 0.625, 0.750, and 1.000 M of NaCl concentrations were tested. For pH experiments, 3, 4, 5.3 (natural pH), 7, 9, and 11 values were selected, and studies were carried out at current densities of 5, 7.5, 10, 12.5, and 15 mA/cm2. The highest removal rate was found as 66.66% at 400 rpm at mixing speed. The optimum conditions were selected as 0.625 M NaCl electrolyte concentration, 5 mA/cm2 current density, wastewater natural pH value (5.3) and turbidity removal was 92.43%, while the energy consumption was 193.5 kWh/m3. As the current density increases, the removal efficiency also increases, but considering the operating cost, this value was chosen as 5 mA/cm2. In the results, it was seen that the most effective supporting electrolyte type in the removal of turbidity by electrooxidation was NaCl, the most suitable ambient conditions were the natural pH value of the wastewater, and the electrooxidation was quite efficient.