Treatment of slaughterhouse wastewaters with Ti/IrO2/RuO2 anode and investigation of energy consumption

Abstract

In the present study, the treatment of slaughterhouse wastewater (SWW) by electro-oxidation method and the energy consumption of the system during the process were investigated. The removal of chemical oxygen demand (COD), color, turbidity, and suspended solids (SS) from wastewater is emphasized. Ti/IrO2/RuO2 was used as the anode material and uncoated titanium was used as the cathode material in the experiments. The experiments were carried out in a glass reactor; the supporting electrolyte (SE) type, concentration, initial pH value, and current density were studied under different conditions. Na2SO4, NaNO3 NaCl, and KCl salts have been used as SE. Salt studies were carried out at 0.1, 0.2, 0.3 and 0.4 M concentrations. The current density was studied at 4.06 mA/cm2, 6.09 mA/cm2, 8.12 mA/cm2, 10.15 mA/cm2, 12.18 mA/cm2. Studies have been carried out at pH 3–9–11 and natural wastewater pH values. The optimum conditions to be used in electro-oxidation of SWW with high organic content have been determined. The results have revealed that as the current density increased, the efficiency increased, and the highest removal was achieved at the natural pH value of the NaCl salt. Studies have shown that color, turbidity, and SS removal for SWW is approximately 90%. COD was found to be 66.46% at the lowest current density. The energy consumption in the selected optimum conditions was found to be 183.6 kWh/m3.