Efficacy of a novel electrochemical membrane-aerated biofilm reactor for removal of antibiotics from micro-polluted surface water and suppression of antibiotic resistance genes

An electrochemical membrane-aerated biofilm reactor (EMABR) was developed for removing sulfamethoxazole (SMX) and trimethoprim (TMP) from contaminated water. The exertion of electric field greatly enhanced the degradation of SMX and TMP in the EMABR (~60%) compared to membrane-aerated biofilm reactor (MABR, < 10%), due to the synergistic effects of the electro-oxidation (the generation of reactive oxygen species) and biological degradation. Microbial community analyses demonstrated that the EMABR enriched the genus of Xanthobacter, which was potentially capable of degrading aromatic intermediates. Moreover, the EMABR had a lower relative abundance of antibiotic resistance genes (ARGs) (0.23) compared to the MABR (0.56), suggesting the suppression of ARGs in the EMABR. Further, the SMX and TMP degradation pathways were proposed based on the detection of key intermediate products. This study demonstrated the potential of EMABR as an effective technology for removing antibiotics from micro-polluted surface water and suppressing the development of ARGs.