Synergistic Effects in Chloride Ion Electrolyte System under Alkaline Conditions

This study investigated the synergistic effect in the anodic oxidation system under alkaline conditions using chloride ions as the electrolyte and determined the synergistic mechanism. Dianil Brown D3G in a certain wastewater was used as the target substance in this study. The oxidation capacity of the anodic oxidation systems with Na2SO4, NaNO3, and NaCl as electrolytes was examined. The results show that the removal rates of total organic carbon (TOC) in the three systems were 21.4%, 25.1%, and 49.5%, respectively, indicating a significant synergistic effect between effective chlorine oxidation and anodic oxidation under alkaline conditions. The high TOC removal rate in the NaCl system is attributed to the oxidation of Cl− into Cl2 in the anode region. When Cl2 dismutates into ClO− and Cl−, it consumes OH−, leading to a decrease in pH. As a result, the oxidation capacity of the anode and ClO− increases with the decrease in pH.