Enhanced adsorption and catalytic degradation of antibiotics by CoFe2O4–NH2@DJB2-900 activated peroxymonosulfate: An experimental and mechanistic investigation

In recent years, with the widespread use of antibiotics in clinical, a large number of residual antibiotics have been discharged into aquatic environments, posing a substantial threat to human well-being. In this paper, the recyclable magnetic catalyst CoFe₂O₄–NH₂@DJB₂-900 (CFN@DJB₂-900) was prepared by combining biochar derived from diaphragma juglans (DJ) with magnetic material CoFe₂O₄–NH₂ (CFN). This catalyst could not only effectively activate peroxymonosulfate (PMS) to degrade levofloxacin (LEF), but also realize rapid separation from the matrix. After four cycles, the LEF removal rate could still maintain at 83.91 %. The quenching experiments and electron paramagnetic resonance (EPR) analysis demonstrated that LEF was degraded by defluorination, depiperazinylation, demethylation and ring opening in CFN@DJB₂-900/PMS system with the help of O₂∙^-, ¹O₂ and electron transfer. The LEF removal rate of 94.32 % was achieved within 10 min. Moreover, the material exhibited wide applicability, good anti-interference ability and reusability. Therefore, this study provided a simple and feasible strategy to prepare an efficient activator CFN@DJB₂-900 for the degradation of levofloxacin.