Oxidative Removal of Dichloromethane by Electro-Activated Persulfate in a Dual-Chamber Reactor

Abstract

Decomposition of dichloromethane (DCM) in water was carried out by electrolysis in combination with persulfate oxidation, and a significant synergistic effect was found in the anode chamber of a dual-chamber electrochemical reactor isolated by a DuPont proton exchange membrane. Experiments were conducted in batch mode to investigate the effects of various operating variables on the removal of DCM in water, such as different titanium-based electrodes, initial persulfate concentration, cell voltage, initial contaminant concentration, temperature, and initial pH. We found that Ti electrode had higher oxidation activity against DCM than IrO2-RuO2/Ti electrode and TiO2 electrode. The removal efficiency of electro-activated persulfate on DCM was positively correlated with initial persulfate concentration, cell voltage, and temperature, but negatively correlated with initial contaminant concentration. Lower initial pH facilitates the rapid removal of DCM. The results showed that the removal rate of 10 mg/L DCM after 180 min was 95.63 (±2.3)%, the TOC removal rate was 51.8%, and the activation energy was 89.905 kJ/mol. In general, the electro-activated persulfate method could effectively remove DCM from wastewater and had high potential application value in DCM treatment in sewage and groundwater.