Promoted electrochemical degradation of triclosan with persulfate on Fe-Ni oxide modified graphite felt cathode

Abstract

Advanced oxidation processes (AOPs) based on persulfate (PS) have shown great potential in wastewater treatment. In this work, FeNiO-modified Graphite felts (GF) cathodes (FeNiO/GF) were prepared to construct an activation system for electrochemical activation of persulfate (EA-PS). The effect of condition parameters (current density, PS concentration and pH) on the degradation of triclosan (TCS) in the EA-FeNiO/GF-PS system was investigated. The results showed that FeNiO loaded on the GF enhanced the cathodic activation of PS. The EA-FeNiO/GF-PS system showed excellent degradation of various pollutants at PS concentration of 1.0 mM and current density of 10 mA/cm2. Electron paramagnetic resonance and free radical quenching experiments showed that •OH, SO4•–, O2•– and 1O2 all contributed to the degradation of triclosan (TCS), with SO4•– and •OH being the major free radicals. The electrochemical performance tests and the XPS characterization of the FeNiO electrode results demonstrated that the valence cycling of Fe and Ni was accelerated under the action of an electric field. In addition, FeNiO/GF had excellent reusability and was unaffected by the actual water matrices. This study provided an effective strategy for the degradation of organic pollutants in water treatment.