Pyrolysis of penicillin fermentation residue and sludge to produce biochar: Antibiotic resistance genes destruction and biochar application in the adsorption of penicillin in water

Abstract A process of antibiotic fermentation residue and sludge pyrolysis to produce biochar was proposed, with antibiotic resistance genes destruction and biochar application in the adsorption of penicillin in water. The results showed that the β-lactam resistance genes were completely destroyed during pyrolysis. The prepared biochar from antibiotic fermentation residues (AFRB) and sludge (AFSB) at 800 °C and 600 °C had a good adsorption effect on the low concentration penicillin in water, with removal efficiencies of 93.32% and 98.50% for penicillin in aqueous solution and maximum adsorption capacities of 44.05 mg/g and 23.26 mg/g, respectively. Characterization of AFRB revealed that its surface was predominantly aromatic carbon, AFSB contained significant amounts of Fe3O4. Weak interactions (H‧‧‧π, H‧‧‧O˭C, π-π interactions) and active sites (aromatic ring, H and –C˭O groups) of penicillin with aromatic structures on AFRB and the chemisorption (–C˭O–Fe–, –C˭OO–Fe–), and active sites (–C˭O, –COO– groups) of penicillin on the (110) surface of Fe3O4 on AFSB were revealed by quantum chemical methods. This work provides a novel pathway for the risk reduction of antibiotic production residue and sludge associated with the generation of biochar for antibiotic removal from the environment.