Activation of Peracetic Acid with Lanthanum Cobaltite Perovskite for Sulfamethoxazole Degradation under a Neutral pH: The Contribution of Organic Radicals

Advanced oxidation processes (AOPs) are effective ways to degrade refractory organic contaminants, relying on the generation of inorganic radicals (e.g., (•)OH and SO(4)(•−)). Herein, a novel AOP with organic radicals (R-O(•)) was reported to degrade contaminants. Lanthanum cobaltite perovskite (LaCoO(3)) was used to activate peracetic acid (PAA) for organic radical generation to degrade sulfamethoxazole (SMX). The results show that LaCoO(3) exhibited an excellent performance on PAA activation and SMX degradation at neutral pH, with low cobalt leaching. Meanwhile, LaCoO(3) also showed an excellent reusability during PAA activation. In-depth investigation confirmed CH(3)C(O)O(•) and CH(3)C(O)OO(•) as the key reactive species for SMX degradation in LaCoO(3)/PAA system. The presence of Cl(−) (1–100 mM) slightly inhibited the degradation of SMX in the LaCoO(3)/PAA system, whereas the addition of HCO(3)(−) (0.1–1 mM) and humic aid (1–10 mg/L) could significantly inhibit SMX degradation. This work highlights the generation of organic radicals via the heterogeneous activation of PAA and thus provides a promising way to destruct contaminants in wastewater treatment.