One-step synthesis of magnetic catalysts containing Mn3O4-Fe3O4 from manganese slag for degradation of enrofloxacin by activation of peroxymonosulfate

Landfill disposal of manganese slag is a significant environmental concern on both local and global levels. Using manganese slag to synthesis catalysts to degrade organic pollutants in wastewater is a promising pathway for the solid waste treatment. Here, we propose a simple method to prepare magnetic catalysts containing Mn 3 O 4 -Fe 3 O 4 (MMF) using manganese slag as raw materials. The MMF exhibits excellent degradation performance for enrofloxacin (ENR) with 97 % removal efficiency within 30 min and can be rapidly isolated from wastewater by magnet. Electron paramagnetic resonance (EPR) and quenching experiments demonstrated that 1 O 2 produced by the non-radical pathway is the principal active substance for ENR degradation. X-ray photoelectron spectroscopy (XPS) and density-functional theory (DFT) calculations indicate that Mn and Fe in MMF provide electrons for PMS activation and that the presence of Fe promotes the activation of the PMS and the cycling of Mn. This work paves the way for developing magnetic catalysts from manganese slag for the treatment of organic pollutants via advanced oxidation process.