Critical review of perovskites-based advanced oxidation processes for wastewater treatment: Operational parameters, reaction mechanisms, and prospects

Abstract

In the field of advanced oxidation processes (AOPs) of wastewater, many materials can be used as heterogeneous catalysts. The role of these catalysts is to activate oxidants and generate reactive oxygen species (ROS) to decompose refractory pollutants. Perovskite oxide, an emerging catalyst in the field of AOPs, has been extensively studied in wastewater treatment. Nevertheless, the application of perovskite in AOP systems still faces some problems, such as leaching of metal ions, a small surface area, a low number of active sites, etc. Herein, this critical review comparatively examines the activation mechanisms of peroxymonosulfate, hydrogen peroxide, and peroxydisulfate. Furthermore, the formation pathways of oxidizing species based on recent advances in experimental and theoretical studies were evaluated. In addition, the impacts of water parameters and constituents such as initial pH, oxidant concentration, catalyst dosage, natural organic matter, halide, phosphate, and carbonate were discussed. Finally, a critical discussion and prospects of mechanism exploration and possible materials development are proposed to confront the existing challenges in the application of perovskite oxides in AOPs.