Effects of an electric field and zero valent iron on anaerobic treatment of azo dye wastewater and microbial community structures

► The coupling of electric field and ZVI in an aerobic reactor led to a significant increase in removal of COD and color of azo dye wastewater. ► The performance of the reactor would be enhanced with raising the potential supplied. ► The abundance of methanogens responsible for COD removal and microbial strains for decolorization significantly increased in the hybrid reactor.