Enhancement of bioelectricity generation by integrating acidogenic compartment into a dual-chambered microbial fuel cell during rice mill wastewater treatment

[Display omitted] •Acidogenic chamber incorporated with dual-chambered microbial fuel cell.•Acidification yield of 56 % was obtained in the effluent of acidogenic chamber.•Power density of 2.35 W/m3 and chemical oxygen demand removal of 75 % was achieved.•Volatile fatty acid rich anolyte reduced solution resistance in microbial fuel cell.•Improved energy recovery compared to microbial fuel cell without acidogenic chamber. In this study, an acidogenic compartment was attached to a dual-chambered MFC. Rice mill wastewater was acidified in the acidogenic chamber to enhance the biodegradation of complex organics before feeding to MFC. The system was operated under HRT of 12 h (A-MFC12) and 15 h (A-MFC15). The performance of the acidogenic chamber-MFC unit was compared with a conventional dual-chambered MFC (C-MFC15). The maximum total volatile fatty acid (VFA) accumulation was found to be mg 991.21 mg COD/L for A-MFC12, and 560 mg COD/L for A-MFC15, which corresponds to the acidification yield of 78.35 ± 1.19 % and 55.94 ± 1.36 %, respectively. The maximum volumetric power density achieved in A-MFC12 (4.08 ± 0.08 W/m3) was higher than that of A-MFC15 (2.34 ± 0.07 W/m3), and C-MFC15 (2.11 ± 0.04 W/m3). The findings suggest that integrating acidogenic pre-treatment induced a positive effect on bioelectricity generation and substrate removal efficiency of the MFC.