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

Abstract

Advanced oxidation processes (AOPs) are e_ective ways to degrade refractory organic contaminants, relying on the generation of inorganic radicals (e.g.,_OH and SO4_ô). Herein, a novel AOP with organic radicals (R-O_) was reported to degrade contaminants. Lanthanum cobaltite perovskite (LaCoO3) was used to activate peracetic acid (PAA) for organic radical generation to degrade sulfamethoxazole (SMX). The results show that LaCoO3 exhibited an excellent performance on PAA activation and SMX degradation at neutral pH, with low cobalt leaching. Meanwhile, LaCoO3 also showed an excellent reusability during PAA activation. In-depth investigation confirmed CH3C(O)O_andCH3C(O)OO_as the key reactive species forSMXdegradation in LaCoO3/PAAsystem. The presence of Clô (1-100 mM) slightly inhibited the degradation of SMX in the LaCoO3/PAA system, whereas the addition of HCO3 ô (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.