Efficient degradation of Enrofloxacin with novel magnetic MnFe2O4/NiS2 composite as an activator of peroxymonosulfate

[Display omitted] •Magnetic MnFe2O4/NiS2 nanocomposites were prepared as the PMS activator.•The enhanced mechanism of MnFe2O4/NiS2-PMS system was proposed.•Ecotoxicity of degradation intermediates of ENR was investigated by T.E.S.T project.•The degradation mechanisms of ENR were proposed. The development of highly active and recoverable heterogeneous catalysts for peroxymonosulfate (PMS) activation to remove the persistent presence of antibiotics in aquatic environments, such as Enrofloxacin (ENR), remains a significant challenge. Here, we introduce a pioneering magnetic nanocomposite catalyst, MnFe2O4-NiS2, synthesized via a two-step hydrothermal process, which activates PMS to efficiently degrade ENR. The optimized 0.25MnFe2O4-NiS2/PMS system reached an ENR removal efficiency of 89.9 % within 90 min, outperforming both NiS2/PMS and MnFe2O4/PMS by 5.6 and 2.5 times, respectively. Quenching experiments and electron spin response analysis confirmed SO4•- and •O2– as the primary reactive oxygen species. The enhanced mediated electron transfer capability of the 0.25MnFe2O4-NiS2 nanocomposite improved the redox cycling of Ni (Ⅱ), Mn (Ⅱ) and Fe (Ⅲ) on its surface, as verified by Density Functional Theory calculations. Furthermore, the activation of surface PMS complexes (PMS*) played a crucial role in ENR degradation. The proposed degradation pathways of ENR were confirmed, and toxicity analysis indicated a decrease in intermediate toxicity with the 0.25MnFe2O4-NiS2/PMS system. This study presents an innovative magnetically recoverable, multifunctional catalyst with easy reusability for potential applications in the degradation of organic pollutants.