Performance enhancement of electrochemical degradation of H-acid wastewater via novel membrane electrode assembly electrolyser

A membrane electrode assembly (MEA) based electrolyser is designed and fabricated for H-acid wastewater treatment and harmful chemical degradation. The electrochemical O3 and H2O2 generation performance has been greatly enhanced owing to the nano PbO2 catalyst on the anode and the PTFE/C catalyst on the cathode. Since the anode oxidation (AO) combined with oxygen reduction reaction (ORR) enhances ·OH radical generation, the in situ AO-ORR coupling system shows better mineralization efficiency and lower electrochemical energy consumption for organic degradation. Additionally, the nano PbO2 anode exhibited excellent stability and maintained high degradation efficiencies after 15 times of successive reuse of the in situ AO-ORR coupling system. Based on 16 identified intermediates categorized as primary, secondary, and downstream intermediates, a possible degradation pathway of the H-acid electrochemical oxidation was proposed and the toxicity was drastically reduced after the degradation.