Effect of the coexposure of sulfadiazine, ciprofloxacin and zinc on the fate of antibiotic resistance genes, bacterial communities and functions in three-dimensional biofilm-electrode reactors.

•Coexposure of Zn increased the ARG abundance in 3D-BER.•Electrical stimulation enhanced pollutants removal but increased their accumulation.•Electrical stimulation enriched ARGs on electrodes but reduced them in the effluent.•The coexposure process significantly affected the bacterial community functions.•The shift in hosts to substrates reduced the abundance of ARGs in the effluent.