Peroxymonosulfate activation through LED-induced ZnFe2O4 for levofloxacin degradation

Recently, a lot of attentions were paid on sulfate (SO4-∙) and hydroxyl (∙OH) radicals-based advanced oxidation processes in degradation of fluoroquinolone antibiotic due to their favorable oxidation potential. This work reported an integrated peroxymonosulfate (PMS) activation process by coupling ZnFe2O4 (ZFO) with energy-saving LED for degradation and defluorination of levofloxacin (LEV). The LEV degradation efficiency reached 88.52 % within 180 min in the ZFO-500/LED/PMS system, which was higher than those of other activation systems. Both SO4-∙ and ∙OH were generated in the integrated ZFO-500/LED/PMS system by the photo-generated electrons and holes activation of PMS under the LED irradiation. The recombination of photo-generated electrons and holes was reduced. Plenty of ∙O2– and 1O2 were produced contributing to LEV degradation. The possible degradation pathways and mechanisms were proposed. This study presented a promising LED-assisted PMS activation process by ZnFe2O4 for antibiotic degradation.