Progress on the Regulation Mechanism of Free Radical and Non-Free Radical Pathways in the Advanced Oxidation Technology of Peroxyacetic Acid

As a green oxidizing agent, peroxyacetic acid (PAA) has made important progress in the activation mechanism and engineering application research. This review systematically analyzes the radical generation laws in UV light activation, transition metal catalysis, and nanomaterial composite non-homogeneous systems, focusing on revealing the ultrasonic activation mechanism in non-homogeneous catalytic systems where the non-radical pathway accounts for more than 70 %. It was shown that the rate of OH generation was enhanced 3.8-fold when the PAA concentration was 0.5 mM (Kobs= 0.42 min-1). By integrating the data of the transition metal/carbon material co-activation system, the dynamic regulation of the active species by environmental factors, such as pH (3.0-8.2), coexisting ions (Cl-, HCO3-, etc), was elucidated. Practical cases demonstrate that the CoFe-LDH/PAA system effectively removes over 90 % of sulfamethoxazole from hospital wastewater, resulting in a 70 % reduction in the cost of treating tons of water compared to the traditional process. In the future, future work should develop machine learning-driven regulation systems to realize the intelligent switching of free radical/non-free radical pathways and break through the bottleneck of complex water quality adaptation.