Remediation of Residual Antibiotics in Fermentation Residues via Packed-Bed DBD Plasma: Feasibility, Optimization, and Mechanism

The safe management of antibiotic fermentation residues (AFR) is challenged by persistent bioactive antibiotics. This study employed packed-bed dielectric barrier discharge (DBD) plasma to degrade pleuromutilin (PLM) via two strategies: (ⅰ) actual PLM residue achieved 94% removal in 40 min with reduced antibacterial activity; (ⅱ) γ-Al 2 O 3 model system attained 98.90% removal in 10 min at 19 kV. Radical quenching confirmed reactive oxygen species ( 1 O 2 , O 2 − ) dominated degradation. LC-MS/DFT analyses revealed plasma preferentially attacks electron-rich PLM sites, forming low-toxicity oxygenated products via hydroxylation and ring-opening oxidation. Packed-bed DBD plasma effectively reduces antimicrobial burden in hazardous AFR, offering a promising sustainable management technology.