Unraveling degradation mechanism and reaction efficacy of sulfamethoxazole via reactive oxygen species dominated radical process

Abstract

Herein, the TiO electrode was combined for the first time with various oxidants to generate reactive oxygen species for the removal of different organic pollutants in an electrochemical oxidation (EO) system. The removal efficiency of organic pollutants, reaction mechanism, and degradation pathway were evaluated by electrochemical tests, reaction kinetics, electron paramagnetic resonance, quantum chemical, and density functional theory calculations. As a result, nearly 100 % removal efficiency of sulfamethoxazole (SMX) was achieved within 12 min with a high kinetic rate constant of 0.259 min, and the kinetic rate constant was strongly dependent on the electrostatic potential. The O2 site on the peroxymonosulfate (PMS) molecule dominated the radical generation for the removal of SMX via the radical and non−radical process. This current study offers a novel approach toward the electrochemical activation of PMS in the elimination and degradation of various organic pollutant from wastewater.