Efficient degradation of tetracycline by CoFeLa-layered double hydroxides catalyzed peroxymonosulfate: Synergistic effect of radical and nonradical pathways

Advanced oxidation technologies based on peroxymonosulfate (PMS) have attracted increasing attention because of their high reactivity and selectivity. Herein, we reported a novel CoFeLa-LDH catalyst, which exhibited excellent performance to activate PMS for tetracycline (TC) elimination. The influence of extra addition, simulation wastewater tests and the reusability experiments were investigated in detail. Remarkably, the quenching experiments and the results of EPR demonstrated the synergistic effect of radical and nonradical pathways in the TC degradation. Free radicals (SO4-(center dot) and HO center dot) played predominant roles in the first 1 min, and then both free and non-free radicals (O-1(2)) interacted with TC. The possible TC degradation pathways were proposed on basis of the intermediates, which were analyzed by UPLC-QTOF-MS/MS. Finally, the reaction mechanisms of TC degradation in CoFeLa-LDH2/PMS system were proposed according to the comprehensive analysis.