Singlet oxygen-dominated electrocatalytic oxidation treatment for the high-salinity quaternary ammonium compound wastewater with Ti/(RuxIry)O2 anode

The widespread application of quaternary ammonium compounds (QAC) has posed a serious hazard to the environment and human being, and high concentration of Cl − in QAC wastewater may further increase the difficulty of pollutants elimination . In this study, such a QAC wastewater under high salinity conditions was chosen as the target, the prepared Ti/(Ru x Ir y )O 2 anode exhibited favorable catalytic performance for the oxidation and mineralization of QAC under high salinity conditions. Increasing the Ru/Ir ratio of Ti-based electrode coating also slightly promoted the inner catalytic capacity. The combination of electron paramagnetic resonance (EPR) and quenching experiments indicates that 1 O 2 served as a main reactive specie in the Ti/(Ru x Ir y )O 2 electrooxidation system. The increase of pH could decrease the removal efficiency of QAC for the reduced 1 O 2 yield, and the rise of Cl − concentration could favor the QAC oxidation, and Cl − was a better electrolyte to promote the oxidation of organic contaminants when compared to Na 2 SO 4 or Na 2 CO 3 . Additionally, the conversion pathway of the model pollutant was tentatively investigated, the results demonstrated that there were almost no halogenated final products residual by electrocatalytic oxidation with Ti/(Ru x Ir y )O 2 anode. This study not only elucidate the reaction mechanism of Ti/(Ru x Ir y )O 2 anode electrocatalytic oxidation of high salinity QAC wastewater, but also may provide an efficacious and eco-friendly method for the treatment of high salinity QAC wastewater.