Constructing antibiotic residue-Fe-based magnetic biochar coupling peracetic acid activation system for efficient pleuromutilin detoxification in wastewater.

Improper disposal of antibiotic wastewater and antibiotic fermentation residues (AFRs) poses serious threats to ecosystems and human health, necessitating the development of effective treatment technologies. In this study, K3Fe(C2O4)3 was employed as a novel feedstock to prepare Fe-based biochar (0.1Fe-BC800) through coupling with AFRs, which was then applied to activate peracetic acid (PAA) for the efficient degradation of pleuromutilin (PLM) in wastewater ("waste-treat-waste"). The results displayed that the invented Fe-BC800/PAA coupling system exhibited superior performance, with a PLM degradation rate of 98.7% and an oxidation rate of kobs= 0.0906 min-1. This improvement was attributed to the enhanced interfacial electron transfer in the reaction system, which promoted the activation of PAA through a combined pathway of radical (•OH, O2•⁻, R-O•) and non-radical species (1O2). The 0.1Fe-BC800/PAA system with the highest PLM degradation rate was further proposed with the help of batch experiments and DFT calculations. A series of ecological toxicological assessments and wheat germination tests confirmed that the toxicity of PLM degradation intermediates was substantially reduced after treatment with the 0.1Fe-BC800/PAA system. Briefly, this study designs and constructs a promising antibiotics detoxification system for wastewater safe treatment, and provides novel insights for hazardous waste recycling of typical biochar materials, which can be applied to efficient PAA activation for water purification.