Photoactivated persulfate for water and wastewater remediations: Mechanisms, applications, and catalysts

Abstract

With the ongoing development of human society and technological advancements, the widespread discharge and utilization of pollutants such as antibiotics, resistance genes, and pathogens present a significant threat to human health. Advanced oxidation technology based on persulfate (PS) is widely used in pollutant treatment. Photoactivation has the advantages of safety, economy, and high efficiency; therefore, it has been applied in water treatment research. However, there have been no reports summarizing how the active species are produced during PS activation. This study elucidated the activation mechanism of the photoactivated PS from two aspects: photoexcitation and photocatalysis. Subsequently, the current research and applications of photoactivated PS to remove pollutants are discussed, important reactive oxygen species (ROS) in this technology are summarized, and the production path and reaction mechanism of ROS are further analyzed and summarized. Finally, it is proposed that the catalyst is the key to photoactivated PS, and the method and mechanism of catalyst modification are discussed to provide theoretical support for improving the efficiency of photoactivated PS technology. This study is helpful for further understanding the mechanism and key factors of photoactivated PS removal from pollutants and provides better prospects for future research.