Formation and control of oxidation byproducts in electrochemical wastewater treatment: A review.

[Display omitted] • Organic and inorganic OBPs were formed during electrochemical oxidation of wastewater. • Wastewater (Cl-, organic matter) and anode ((non)active) types affect OBPs formation. • Optimizing operate parameters (acidic pH and low current) can reduce OBPs formation. • Quenching free chlorine and developing chlorine-inert anode minimize OBPs formation. • The formed OBPs can be post-treated by electrochemical or microbial reduction. Electrochemical oxidation (EO) is an emerging technology for treating recalcitrant wastewater owing to its high efficiency and mild operational conditions. However, the formation of toxic oxidation byproducts (OBPs) poses a great challenge in EO applications. This paper aims to provide a comprehensive review of OBPs formation and potential control strategies, both qualitatively and quantitatively. Correlation analyses reveal that the concentrations of Cl- and types of organic matter have significant effects on organic OBPs formation, while electrode materials influence inorganic OBPs formation. Some experiences learned from disinfection byproducts could help better understand OBP toxicity and develop potential removal methods. OBPs may be controlled through minimizing OBPs formation or post-treatment of the formed OBPs. Both acidic pH and lower current density help mitigate OBPs production. Free chlorine can be quenched through electrochemically generated H 2 O 2 to decrease OBPs formation. Chlorine-inert anode electrodes like graphene-based materials are being developed to achieve efficient EO performance without OBPs formation. Post-treatment technologies include electrochemical reduction and microbial reduction, which can be synergistically integrated with EO. [ABSTRACT FROM AUTHOR]