Multi-targeted removal of coexisted antibiotics in water by the synergies of radical and non-radical pathways in PMS activation

Various antibiotics often coexist in contaminated water which can pose a threat to the ecological environment and human health. Conventional water treatment technologies generally have low efficiency to simultaneously remove multiple antibiotics. To address this issue, a bimetal composite corncob biochar catalyst (Fe-MOF-CC@MoS2) was explored for the peroxymonosulfate (PMS) activation to degrade various antibiotics simulta-neously in this study. The Fe-MOF-CC@MoS2 was prepared by a simple green hydrothermal carbonization method and characterized. The degradation performance of Fe-MOF-CC@MoS2 for coexisted antibiotics from the aqueous phase was evaluated. The results indicated that the Fe-MOF-CC@MoS2/PMS system exhibited a superior degradation efficiency of antibiotics compared to Fe-MOF-CC/PMS system, due to the acceleration of the Fe2+/ Fe3+ cycling by active Mo4+. Fe-MOF-CC@MoS2/PMS system could simultaneously remove four different types of antibiotics, and the removal efficiencies of tetracycline hydrochloride, ciprofloxacin, nitrofurantoin, and sulfamethoxazole were 96.51 %, 92.30 %, 88.96 %, and 80.76 %, respectively. Electron spin resonance and quenching experiments demonstrated that the cooperation of radical (SO4 center dot-, (OH)-O-center dot and O-center dot(2)-) and non-radical (O-1(2)) in the Fe-MOF-CC@MoS2/PMS system led to 14 times higher degradation rate constant than that in Fe-MOF-CC/ PMS system. In addition, the Fe-MOF-CC@MoS2 presented high removal efficiency (76.54 %) for the antibiotics after five cycles. Moreover, the toxicity of contaminated water after degradation was significantly reduced through the growth of Vigna radiata. Finally, the flowing experiment using Fe-MOF-CC@MoS2/quartz sand column proved that Fe-MOF-CC@MoS2 could effectively activate PMS and remediate water contaminated with four coexisted antibiotics. This study may provide a promising alternative for the multi-targeted removal of coexisted antibiotics from real water, meanwhile recovering resources.