Molybdenum disulfide (MoS2): A novel activator of peracetic acid for the degradation of sulfonamide antibiotics

Sulfonamide antibiotics (SAs) are typical antibiotics and have attracted increasing concerns about their wide occurrence in environment as well as potential risk for human health. In this study, we applied a novel advanced oxidation process in SAs degradation by combining molybdenum sulfide and peracetic acid (MoS 2 /PAA). Reactive oxygen species (ROS) including HO ● , CH 3 C(O)O ● , CH 3 C(O)OO ● , and 1 O 2 were generated from PAA by MoS 2 activation and contributed to SAs degradation. The effects of initial pH, the dosages of PAA and MoS 2 , and humic acid for SAs degradation were further evaluated by selecting sulfamethoxazole (SMX) as a target SA in the MoS 2 /PAA process. Results suggested that the optimum pH for SMX removal was 3, where the degradation efficiency of SMX was higher than 80% after reaction for 15 min. Increasing PAA (0.075–0.45 mM) or MoS 2 (0.1–0.4 g/L) dosages facilitated the SMX degradation, while the presence of humic acids retarded the SMX removal. This MoS 2 /PAA process also showed good efficiencies in removing other SAs including sulfaguanidine, sulfamonomethoxine and sulfamerazine. Their possible degradation pathways were proposed based on the products identification and DFT calculation, showing that apart from the oxidation of amine groups to nitro groups in SAs, MoS 2 /PAA induced SO 2 extrusion reaction for SAs that contained six-membered heterocyclic moieties.