BACKGROUND Dimethyl phthalate (DMP) is refractory, persistent and easy to enrich in anaerobic environments. The urgent need to degrade this refractory organic matter with high efficiency can be met by bioelectrochemical technology. In this paper, the degradation characteristics of DMP under different reaction conditions in bioelectrical reactors (BERs) were studied. RESULTS With operation conditions of 400 mg L-1 DMP, 1.3 V applied voltage and 50 h HRT, the highest removal efficiency of DMP was obtained in a BER (84.0%), which was higher than a conventional anaerobic system (Ana) (68.0%). Phthalic acid, heptanedioic acid and other low molecular weight products of DMP were detected in the BER, which shows that the applied voltage can stimulate the intermediate products of DMP into further degradation. Simultaneously, the abundance of microorganisms in the BER was richer than in the Ana. CONCLUSION The higher removal efficiency of DMP, the further degradation of DMP and the richer abundance of bacteria in the BER indicate that electrochemical methods can promote the intensive removal of DMP. (c) 2019 Society of Chemical Industry