Electrochemical Degradation of Diethyl Phthalate under Different Operating Conditions

In this study, different operating conditions were tested for the electro-degradation of diethyl phthalate (DEP) (an emerging contaminant) in aqueous solutions. The results show that the DEP electro-degradation followed pseudo first-order kinetics. The degradation efficiencies and (apparent) rate constants of DEP increased with the increase of current density and solution temperature (activation energy = 8.0 kJ/mol), but decreased with initial DEP concentration. The boron-doped diamond (BDD) anode was significantly better than PbO2 and Pt for DEP degradation and TOC removal. The apparent rate constants were 2.87x10(-4), 2.00x10(-4), and 5.00x10(-5) s(-1) for the degradation of 50 mg/L DEP at 200 mA/cm(2) and 25 degrees C in 0.1 M Na2SO4 solution at BDD, PbO2, and Pt anodes, respectively. After 210 min electrolysis, the BDD achieved total mineralization of 50 mg/L DEP in both 0.1 M Na2SO4 solution and municipal wastewater treatment plant secondary effluent. Hence, the electrochemical method was a promising process for the effective treatment of DEP and similar pollutants in municipal wastewater.