A review on reactive oxygen species generation, anode materials and operating parameters in sonoelectrochemical oxidation for wastewater remediation
Babatope O. Ojo, Omotayo A. Arotiba, Nonhlangabezo Mabuba
Abstract
The application of sonoelectrochemical (SEC) oxidation technique involving the incorporation of ultrasound irradiation into an electrochemical oxidation system has found enormous success for various purposes, especially for organic synthesis and water treatment. Although its industrial application towards the removal of organic contaminants in water is not popular, its success on the laboratory scale is often attributed to the physical and chemical effects. These effects arise from the influence of ultrasound irradiation, thus eliminating electrode passivation or fouling, improving mass transfer and enhancing reactive oxygen species (ROS) generation. The continuous activation of the electrode surface, improved reaction kinetics and other associated advantages are equally occasioned by acoustic streaming and cavitation. This review hereby outlines common ROS generated in SEC oxidation and pathways to their generation. Furthermore, classes of materials commonly employed as anodes and the influence of prominent operational parameters on the performance of the technique for the degradation of organic pollutants in water are extensively discussed. Hence, this study seeks to broaden the significant promises offered by SEC oxidation to environmentally sustainable technology advances in water treatment and pollution remediation. • Generation of reactive oxygen species (ROS) in sonoelectrochemical oxidation systems. • Common and emerging classes of anodic materials in sonoelectrochemical oxidation. • Influence of operating parameters on ROS generation and overall efficiency of sonoelectrochemical oxidation.