Elimination of antibiotics, antibiotic resistance bacteria and resistance genes during treatment of aquaculture effluents with UV and Chlorine : Bench- and pilot-scale

Abstract

There has been increasing concern on the presence of antibiotics, antibiotic resistant bacteria and their resistance genes (ARGs) in aquaculture effluents. Oxidation and disinfection of aquaculture effluents can be an option to eliminate these contaminants but the process efficiency is unclear. In this study, we assessed the elimination efficiency of selected antibiotics (oxytetracycline-OTC and amoxicillin-AMX), ARB (OTC-resistant bacteria), and ARGs (tetB and tetD) during treatment of seawater-based aquaculture effluents with chlorine, UV (254nm) and chlorine followed by UV treatments in laboratory- and pilot-scale treatments. Chlorine, UV, and a combination thereof can achieve considerable levels of elimination of OTC and AMX and inactivation of the ARB and ARGs during treatment of the aquaculture effluents in both bench- and pilot-scale treatments. Comparable elimination/inactivation efficiencies were observed between the bench and pilot treatments. Nevertheless, the inactivation efficiency of ARB and ARGs were much lower than expected due to the particle shielding effects. Thus, further optimization of the particle removal pre-treatment process is recommended.