1,4-dioxane degradation using a pulsed switching peroxi-coagulation process

Abstract

Widely used in chemical product manufacture, 1,4-dioxane is one of the emerging contaminants, and it poses great risk to human health and the ecosystem. The aim of this study was to degrade 1,4-dioxiane using a pulsed switching peroxi-coagulation (PSPC) process. The electrosynthesis of H2O2 on cathode and Fe2þ production on iron sacrifice anode were optimized to enhance the 1,4-dioxane degradation. Under current densities of 5 mA/cm2 (H2O2)and1mA/cm2 (Fe2þ), 95.3 ± 2.2% of 200 mg/L 1,4-dioxane was removed at the end of 120 min operation with the optimal pulsed switching frequency of 1.43 Hz and pH of 5.0. The low residual H2O2 and Fe2þ concentrations were attributed to the high pulsed switching frequency in the PSPC process, resulting in effectively inhibiting the side reaction during the ·OH production and improving the 1,4-dioxane removal with low energy consumption. At 120 min, the minimum energy consumption in the PSPC process was less than 20% of that in the conventional electro-Fenton process (7.8 ± 0.1 vs. 47.0 ± 0.6 kWh/kg). The PSPC should be a promising alternative for enhancing 1,4-dioxane removal in the real wastewater treatment.