Highly Efficient Degradation of Sulfisoxazole by Natural Chalcopyrite-Activated Peroxymonosulfate: Reactive Species and Effects of Water Matrices

In this study, chalcopyrite (CuFeS2), a natural mineral with bimetallic structure, was used as the activator to generate radicals for removing organic pollutants from aqueous solutions via activation of peroxymonosulfate (PMS). Sulfisoxazole (SIX), sulfonamide antibiotic, selected model pollutant. The results showed that highly reactive toward PMS; under conditions 50 µM PMS and 1 g/L chalcopyrite, approximately 95.7% SIX degraded after reaction only 5 min. An increase in loading (0.25–2 g/L) promoted degradation SIX, while elevated levels (0.05–0.5 mM) slightly retarded kinetics. Although best performance observed acidic (pHs 3 4), near complete also achieved at pH 5.5. Identification species revealed both hydroxyl radical sulfate were formed chalcopyrite–PMS oxidation, they responsible SIX. Trace amounts copper iron leached out during activation, heterogeneous homogeneous contributed generation oxidizing radicals. Common water constituents including Cl−, HCO3−, matter their environmentally relevant limited effect on which suggests oxidation has high reactivity stability shows great practical application potential.