Efficient degradation of sulfonamides by CoS-activated peracetic acid advanced oxidation system

Background Advanced oxidation processes are considered one of the most promising techniques for removing persistent organic pollutants in water. To achieve efficient degradation of sulfonamides (SAs), cobalt sulfide (CoS) was synthesized and used as a catalyst for the activation of peracetic acid (PAA) to build a new advanced oxidation system (CoS/PAA). Results The reaction conditions of catalyst dosage, PAA concentration, initial pH and substrate concentration were systematically investigated using sulfamethoxazole (SMX) as a model pollutant. At the optimized conditions (80 mg L −1 CoS and 0.5 mmol L −1 PAA), four SAs (sulfisoxazole, sulfadiazine, sulfadimethoxine and SMX, each at 5 mg L −1 ) could be completely degraded within 2–10 min. This CoS/PAA system could withstand interference from inorganic anions of Cl − and H 2 PO 4 − , and the leaching of cobalt ions in treated water was well below the environmental quality standards of 1 mg L −1 in China. The quenching experiment revealed that organic free radicals (R  O • ) played a key role in the degradation process. Moreover, a removal rate of 95.03% for SAs in complex pond water was achieved. Conclusion The CoS/PAA system showed promising application prospects in the SA-containing wastewater treatment. © 2025 Society of Chemical Industry (SCI).