Nature, Mechanisms and Reactivity of Electrogenerated Reactive Species at Thin-Film Boron-Doped Diamond (BDD) Electrodes During Electrochemical Wastewater Treatment

Electrooxidation of hazardous organic pollutants contaminating wastewater using thin-film boron-doped diamond (BDD) electrodes is an efficient and well-studied treatment technique. In this review, the three main reactive species, namely: reactive oxygen, chlorine and sulfate species, which can be electrogenerated and then participate in the oxidation processes during electrooxidative wastewater treatment using BDD electrodes, are discussed. The main factors affecting the nature and quantity of the electrogenerated reactive species, specifically the composition of the BDD electrode (doping level and sp(3)/sp(2) ratio) and the operating parameters (working current density and composition of water matrix been electrolyzed) were explained with relative examples. Extensive discussion on mode and reactivity of the three reactive species with organic pollutants during electrooxidation was provided and the future perspectives and direction of research on reactive species generated on BDD electrodes were also discussed.