Abstract:
This work was carried out to study the effect of parameters and optimum condition for treating wastewater from biodiesel production plant. The investigated parameters were air flow rate (0.5-2.5 l/min), types of cathode (graphite, stainless steel, Ti/RuO2), operating time (15-180 min), initial pH of wastewater (2-7) and current density (78-233 A/m2). At optimum condition: initial pH of wastewater of 4, current density of 78 A/m2, operating time of 180 min, air flow rate of 1.5 l/min by using graphite electrode, greater than 54.9, 63.9 and 85.9% of COD, BOD and oil&grease were removed, respectively. The reduction rate of COD BOD and oil&grease were the 2nd order reaction. The re-treatment of wastewater by electro-Fenton process can enhance a more reduction of pollutant in treated wastewater. The concentration of oil&grease was reduced from 50,725 to 13.5 mg/l after the 9th times of wastewater treatment. Significant reductions of COD and BOD were also observed, but their concentrations were still higher than the acceptable value for discharging.