Recent advances in peracetic acid-based advanced oxidation processes for emerging pollutants elimination: A review

The utilization of peracetic acid (PAA) as an oxidant in advanced oxidation processes (AOPs), known as PAAbased AOPs, has garnered significant attention in the field of water treatment due to its minimal toxicity. This review comprehensively presents the advancements in research on various methods for activating PAA, including metal catalysts, non-metallic catalysts, external energy input and natural anions. Thorough examination was conducted on the impacts of operational parameters such as pH value and PAA concentration on both the reaction system and pollutant conversion process. Furthermore, the key issues such as the change of PAA/H 2 O 2 concentration, the types of active substances and their contribution rates, as well as relatively accurate catalytic mechanism are discussed in detail. Given the crucial role played by organic free radicals in degrading emerging pollutants within PAA-based AOPs systems, our focus was directed towards identifying specific organic radicals generated within the PAA system. Finally, we comprehensively analyze challenges and difficulties encountered in current research on PAA-based AOPs systems along with potential avenues for future investigation.