Bimetallic oxychloride as an efficient oxone activator: Radical and non-radical oxidation of non-steroidal anti-inflammatory drugs

[Display omitted] •PMS activation with novel CoFeOCl was efficient for removal of PPCPs.•Key role of OH and 1O2 were confirmed at acid and basic pH.•Cycles of Co2+/Co3+ and Fe2+/Fe3+ were answerable for radical generation.•The calculated toxicity of DBPs decreased with pH increase. A novel iron-cobalt mixed oxychloride (CoFeOCl) nanosheet, with a plane size in the ranges of 0.2–1.0 μm and a thickness of 30–40 nm, was manufactured firstly and employed as catalyst for peroxymonosulfate (PMS) activation. The CoFeOCl/PMS system exhibits excellent catalytic activity for non-steroidal anti-inflammatory drugs removal at buffered pH 5.5–8.5 with extremely low catalyst dosage (0.03 g/L). The mechanism of PMS activation by CoFeOCl indicated that OH and 1O2 played a key role at pH 5.5–7.0 and pH 8.5 respectively, and O2– was involved for all pHs. The cycle of Co2+–Co3+ and Fe2+-Fe3+ were answerable to OH and 1O2 generation. Furthermore, CoFeOCl/PMS pre-oxidation before chlorination engendered in a reduce in the concentration of total disinfection by-products (DBPs) at pH 8.5. A feasible reaction pathway of DBPs formation was examined with density functional theory (DFT) calculation. The findings provide a new routine for effective PMS activation.