Peracetic acid-based advanced oxidation processes for the degradation of emerging pollutants: A critical review

Abstract

An ever-increasing number of anthropogenic pollutants, referred to as emerging pollutants (EPs), have been of concern in recent years. These pollutants are known for the potential risk that they pose in the environment, and have been consistently found in surface, waste, and potable waters. Moreover, some of them are persistent to conventional treatments and in the environment. Advanced oxidation processes (AOPs) are widely used technology for the removal of EPs The use of peracetic acid (PAA) as an oxidant AOP for the treatment of EPs has attracted increasing interest, owing to its ease of activation, and to the selectivity of the organic radicals that are generated in these processes towards electron rich sites, which makes them more robust against the effect of scavenging agents in real matrices. This work presents a critical analysis of the advantages, disadvantages, and opportunities of PAA-based processes. Several strategies for PAA activation were analyzed, including UV and transition metal activation, heterogeneous catalysis, thermal and microwave activation, and phosphate induced activation. It was found that PAA-based AOPs seem to have several advantages over other widely studied processes. Some key perspectives for research include testing of these processes with a variety of EPs, analysis of transformation products and their toxicity in the treated effluents, multivariate optimization of the process, direct comparison with widely studied oxidants, and experimentation for escalation and implementation. Nevertheless, PAA-based AOPs seem to be a promising alternative to conventional AOPs.