Activation of peroxymonosulfate for degradation of norfloxacin by Mn-doped zeolitic imidazolate framework-67 nanocrystals

Abstract

In recent years, the abuse of antibiotics has brought a great environmental problem. Therefore, it is important to develop highly efficient technology for treating antibiotic pollutants. Herein, Mn-doped zeolitic imidazolate framework-67 (Mn-ZIF67) nanocrystals were prepared using a modified solvothermal method and then characterized by various techniques. The prepared Mn-ZIF67 was applied to activate peroxymonosulfate (PMS) for the degradation of norfloxacin (NOR). The degradation results illustrated that a removal rate of 85% and a mineralization rate of 42% were achieved in the degradation of NOR within 30 min under the optimized reaction conditions. Additionally, free radical quenching experiments proved that the main active substance in the reaction system was SO₄˙⁻. Besides, the material exhibits good recycling performance and can achieve a 70% NOR degradation rate after 5 cycles. According to the degradation intermediates detected by LC-MS, three possible degradation pathways of NOR were inferred. This work proves that Mn-ZIF67 has a good catalytic effect and it could be considered as a new and perspective material for organic wastewater treatment.