Advances in research of pollution, degradation and removal of antibiotics and antibiotic resistance genes in the environment

With the widespread application of antibiotics and other antimicrobic agents, the residuals and potential hazards in both natural and human environment have raised public concerns. Based on current research, our review documents the sources of antibiotic and antibiotic resistant genes (ARGs) and the contamination status, analyzes their relationships and propagation mechanisms, and summarizes treatment technologies. Antibiotics and ARGs are commonly detected in water, soil and air, with comparatively higher levels in human environment, including wastewater treatment plant and solid waste processing chains. ARGs are induced by antibiotic residuals accumulated in the environment, but ARGs propagation is dominated by horizontal gene transfer (HGT) and the composition of microbial communities. In addition, other factors including temperature, light, and microbial communities all could impose effects on the degradation of ARGs and antibiotics, among which light is the most crucial factor in natural environment. In the engineered treatment systems, UV disinfection and biochemical degradation function well in ARGs and antibiotic removal, though not always so. Given these results, the review suggests that future study should focus on the mechanisms of antibiotics and ARGs propagation as well as specific treatment technologies.