Peroxymonosulfate activation by tin(IV) phosphate supported cobalt composite for acetaminophen degradation: Performance and mechanism

Abstract

Tin(IV) phosphate-supported cobalt composite (Co-SnP) was prepared and employed as a heterogeneous activator of peroxymonosulfate (PMS) for acetaminophen (APAP) degradation. The results indicated that almost all APAP (5 mg L−1) was eliminated by PMS (0.5 mM) assisted with Co-SnP (0.2 g L−1) in an initial pH range of 7–9 within 15 min, mainly owing to the role of OH and SO4−, with contributions of 59.7 % and 39.6 %, respectively. The rate constant (k) value increased gradually with the increase in catalyst dosage and PMS concentration. APAP degradation was suppressed by Cl−, HCO3− and humic acid but promoted by NO3−. The Co-SnP/PMS system exhibited strong oxidation ability toward APAP in real water matrices and toward other organic pollutants (rhodamine B, phenacetin, bisphenol A, and sulfisoxazole), indicating the outstanding catalytic performance of Co-SnP for PMS activation. Furthermore, the superior stability and reusability of the Co-SnP catalyst were confirmed through four consecutive uses. Finally, the intermediates of APAP degradation were identified and the APAP degradation pathways were proposed. This work demonstrates the potential application of the Co-SnP/PMS system in the elimination of organic pollutants from water and provides a novel avenue for the recovery and utilization of phosphorus and cobalt ions in wastewater.