Pyrolytic conversion of cattle manure and acid mine drainage sludge into biochar for oxidative and adsorptive removal of the antibiotic nitrofurantoin

Antibiotics in aquatic environments can foster the development of antibiotic-resistant bacteria, posing significant risks to both living organisms and ecosystems. This study explored the thermo-chemical conversion of cattle manure (CM) into biochar and assessed its potential as an environmental medium for removing nitrofurantoin (NFT) from water. The biochar was produced through the co-pyrolysis of CM and acid mine drainage sludge (AMDS) in a N2 condition. The gaseous and liquid products generated during pyrolysis were quantified and characterized. The biochar exhibited both catalytic and adsorptive capability in NFT removal. It effectively activated persulfate to drive oxidative degradation of NFT via radical (SO4•- and •OH) and non-radical (1O2) pathways. NFT adsorption on the biochar involved multiple binding mechanisms, including electrostatic, hydrogen bonds, and π-π EDA interactions, as evidenced by XPS analysis before and after the reaction. Furthermore, the biochar's performance stability was demonstrated through five cycles of reuse and leaching tests. These findings present a viable approach to generate energy from waste by co-pyrolyzing of livestock manure and metal-containing industrial waste, while also producing environmental media capable of removing antibiotics from wastewater through diverse mechanisms. [Display omitted] •Cattle manure and acid mine drainage sludge were co-pyrolyzed.•Biochar showed catalytic and adsorptive abilities for nitrofurantoin (NFT) removal.•NFT degradation was driven by SO4.•-, •OH, and 1O2 from persulfate activation.•NFT adsorption on biochar involved multiple binding mechanisms.•Performance of biochar was demonstrated through reusability and leaching tests.