Modification of graphite felt doped with nitrogen and boron for enhanced removal of dimethyl phthalate in peroxi-coagulation system and mechanisms.

Abstract

To enhance the generation of hydrogen peroxide (H2O2), a modified graphite felt cathode doped with nitrogen and boron was developed and used in peroxi-coagulation system to degrade dimethyl phthalate (DMP). After a simple modification method, the yield of H2O2 on cathode increased from 9.39 to 152.8mg/L, with current efficiency increased from 1.61 to 70.3%. Complete degradation of DMP and 80% removal of TOC were achieved within 2h at the optimal condition with pH of 5, cathodic potential of - 0.69V (vs. SCE), oxygen aeration, and electrode gap of 1cm. Possible mechanism with synergistic effect of electro-Fenton and electrocoagulation process in the peroxi-coagulation system was revealed via quenching experiments. The prospect of this system in the effluent of landfill leachate and domestic sewage was studied, achieving 50% and 61% of DMP removal in 2h. This efficient system with simple modified cathode had promising prospects in practical applications.