Efficient removal of tetracycline using U-type continuous-flow bioelectrochemical system without ion exchange...

A U-type membraneless continuous-flow bioelectrochemical system was developed to efficiently remove tetracycline and antibiotic resistance genes from synthetic wastewaters at hydraulic retention time of only eight hours. At the TC concentration of 20-80 mgL^-1 in feed, the removals of tetracycline all exceeded 95%, over 60-1200 mgL^-1 chemical oxygen demand, 30-150 mgL^-1 NH₄⁺-N, and at 5-25 °C, superior to the performances reported in literature. The maximum power of the BES system peaked at 0.416 Wm^-3 at 20 mgL^-1 TC feeding, corresponding to open circle voltage of 0.90 V and internal resistance of 799.8 Ω. The community analysis showed that the elevated TC loadings forced the predominate population to be evolved to TC-degrading consortium. The relative abundances of tetA, tetC, tetO, tetQ, and tetW in treated effluent ranged 1.20 × 10^-6 to 2.60 × 10^-4, revealing that the present BES reactor has superior removal efficiency of antibiotic resistance genes.