BACKGROUND: The microbial electrolysis cell (MEC) has been widely reported as an efficient strategy to enhance anaerobic digestion. However, the role of the MEC during acidogenesis for treatment of sulfate-containing wastes remains unclear. In this study a pair of electrodes was placed into an acidogenic reactor to form MEC-based acidogenesis to investigate its performance in sulfate-containing wastewater treatment. RESULTS: The MEC obviously improved anaerobic acidogenesis treating sulfate-containing wastewater. Higher COD removal and sulfate reduction were obtained in the MEC-based acidogenesis even underhigh sulfate loading conditions. The MEC accelerated the conversion of substrate to acetate, indicating that acidogenesis was enhanced. Fluorescence in situ hybridization (FISH) analysis showed that exoelectrogenic bacteria were enriched in the anodic biofilm. CONCLUSION: The syntrophic metabolism between anodic exoelectrogenic bacteria and anaerobic fermentative bacteria might accelerate the anodic decomposition of complex substrates as well as cathodic sulfate reduction, then providing a positive environment for sulfate reduction during acidogenesis. (C) 2017 Society of Chemical Industry