Amorphous zirconium phosphate as a recycled material anchored cobalt for catalytic degradation of phenacetin via peroxymonosulfate activation

Herein, zirconium phosphate as a recycled material was used for the first time to support cobalt (Co-ZrP) serving as a catalyst for activating peroxymonosulfate (PMS) to remove phenacetin (PNT). It was found that PNT (5 mg L-1) was completely eliminated in the Co-ZrP (0.2 g L-1)/PMS (2 mM) system in an initial pH range of 5 to 7 within 10 min. The pseudo-first-order rate constant of PNT degradation by PMS combined with Co-ZrP was 0.625 min(-1), far faster than those with ZrP (0.0065 min(-1)) and with Co3O4 (0.104 min(-1)). The introduction of HA and HCO3- significantly inhibited PNT removal, while the addition of H2PO4- accelerated PNT elimination in the Co-ZrP/PMS system. Nevertheless, PNT could still be completely removed by Co-ZrP-activated PMS in actual water. Recycling experiments indicated that the degradation efficiency of PNT could reach 98 % after four cycles and calcining Co-ZrP could completely restore its catalytic activity. In addition, effective decomposition of chloramphenicol, bisphenol A, sulfamethazine and rhodamine B was also achieved by Co-ZrP-activated PMS within 15 min. Hence, the combination of Co-ZrP and PMS had great potential in removing organic pollutants from water environment. EPR analysis and quenching tests suggested that the rapid degradation of PNT was mainly ascribed to the generation of center dot OH and SO4 center dot- in the Co-ZrP/PMS system. Based on HPLC-HRMS analysis, the main degradation products were determined and the possible degradation pathways were further proposed.