Impact of graphene oxide addition on pharmaceuticals removal in anaerobic membrane bioreactor

The addition of conductive materials to the anaerobic digestion bioreactor was suggested to enhance microbial activity. In the present work, an anaerobic membrane bioreactor treating municipal wastewater was operated for 385 days. The impact of different graphene oxide concentrations on the removal target pharmaceuticals and microbial community dynamics was investigated. The addition of graphene oxide did not impact the reactor stability, whereas the removals of antibiotics (e.g., trimethoprim and metronidazole) were enhanced. A shift in the microbial community was detected after the addition of 50–900 mg L−1 of graphene oxide, with the proliferation hydrogenotrophic methanogens. The proliferation of syntrophic microorganisms may indicate interactions via direct interspecific electron transfer. The obtained results suggest that the addition of graphene oxide at low mg L−1 concentrations to an anaerobic membrane bioreactor may be considered to improve the removal of antibiotics from municipal wastewater ; This research is funded by AEI (Agencia Estatal de Investigación, Spanish Government) through project ANTARES (PID2019-110346RB-C22). The authors acknowledge the support from the Economy and Knowledge Department of the Catalan Government through a Consolidated Research Group (ICRA-TECH - 2021 SGR 01283). ICRA researchers also acknowledge the funding from the CERCA program. O. Casabella-Font acknowledges funding from the Secretariat of Universities and Research from Generalitat de Catalunya and the European Social Fund for his FI fellowship (2022 FI_B1 00122). M. Ponzelli acknowledges funding from European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement – MSCA-ITN-2018 (EJD Nowelties, grant number 812880) ; 6