Generation of Reactive Oxidants during Nitrate Electrolysis: An Approach to the Simultaneous Removal of Nitrate and Organic Contaminants

This study demonstrated that organic contaminants are effectively oxidized by reactive oxidants generated through multiple pathways during nitrate (NO 3 – ) electrolysis under acidic conditions. The electrochemical degradation of benzoic acid (BA) was 3.6 times faster in the NO 3 – electrolyte than in the inert perchlorate (ClO 4 – ) electrolyte, suggesting that BA degradation is facilitated by specific reactions with intermediates formed during NO 3 – electrolysis. A series of electrolytic experiments and analyses confirmed that BA degradation during NO 3 – electrolysis occurs through three reaction pathways: (i) hydroxylamine (HA) produced by cathodic reduction of NO 3 – anodically produces peroxynitrous acid (ONOOH), which oxidizes BA via a hydroxyl radical (cathodic/anodic coupled pathway), (ii) the cathodic reduction of NO 3 – yields ONOOH through the reaction of nitrous acid (HNO 2…