Post-Treatment of Coking Industry Wastewater by the Electro-Fenton Process

摘要

Effluents of the coking industry cannot be effectively treated in biological treatment units because of non-biodegradable organic matters and phenolic compounds present in the wastewater. In this study, post-treatment of biologically treated coking wastewater via the electro-Fenton process was investigated to minimize the effects of discharge of this kind of wastewater on the environment. The electro-Fenton experiments were performed using cast iron electrodes. Chemical oxygen demand (COD) and phenol were selected as the target parameters. The optimum operating conditions were as follows: reaction time = 10 minutes, pH = 3.0, electrical current = 1.0 A, and [H_2O_2] = 2000 mg/L. Under these conditions, COD and phenol removal efficiencies were 67.8% and 98.0%, respectively. In addition, it was determined that COD removal followed first-order reaction kinetics. Consequently, the electro-Fenton process was determined as an effective alternative post-treatment method for coking industry effluents.