Biological treatment strategies for antibiotic contamination: mechanisms, applications, and future perspectives

The persistence of antibiotic residues in aquatic environments poses significant environmental and health risks. Biological treatment technologies, owing to the cost-effectiveness and environmental benefits, represent a crucial strategy for addressing this challenge. This review systematically elucidates the degradation mechanisms centered on microbial cometabolism, which involves a series of biochemical reactions mediated by functional microorganisms, including hydrolysis, oxidation, reduction, and side-chain modification and cleavage. It also provides a comprehensive evaluation of treatment systems ranging from conventional processes to emerging enhanced technologies such as bioaugmentation, immobilization, and biomaterial coupling. Two major challenges in this field are clearly identified: the inhibitory effects of antibiotics on functional microorganisms, and the secondary dissemination risk of antibiotic resistance genes (ARGs) dissemination. In response, the paper further summarizes recent advances in frontier approaches, such as process intensification, novel material coupling, synthetic biology tools, resource recovery, and intelligent model-based control. These strategies collectively aim to synergistically improve treatment efficiency and mitigate environmental risks. This review aims to provide a valuable reference for developing more efficient and safer biological treatment technologies for antibiotic-containing wastewater.