Peroxymonosulfate activation using MnFe2O4 modified biochar for organic pollutants degradation: Performance and mechanisms

Exploiting stable and high-performance catalysts is a challenge in remediating organic pollutants (OPs) during advanced oxidation. Herein, this study reported MnFe2O4 decorated biochar (MnFe2O4/BC) as an adsorptive-catalyst for peroxymonosulfate (PMS) activation to degrade OPs. BC as support not only increased the stability and dispersibility but also decreased the particle diameter of MnFe2O4. We demonstrated various OPs (50 mL, 20 mg·L−1) (including malachite green, bisphenol A, methylene blue, sulfamethoxazole, tetracycline, and thiacloprid) was synergistically adsorbed and oxidized within 10 min with the introduction of PMS (0.65 mM) in the MnFe2O4/BC system. The degradation efficiency was more than 95% after recycling six times. Results of discrete Fourier transform revealed that PMS was preferentially adsorbed on BC doping sites (−4.31 eV to −3.85 eV) and MnFe2O4 parts (−9.67 eV), and then the adsorbed–PMS was activated. These results confirmed that oxidation occurs through radical–induced and non–radical pathways in the MnFe2O4/BC system. Overall, the MnFe2O4/BC showed efficient performance, also this work provides a new insight for understanding of the PMS activation mechanism.