An up-flow anaerobic sludge blanket reactor-microbial fuel cell-biological aerated filter (UASB-MFC-BAF) system was developed for simultaneous bioelectricity generation and molasses wastewater treatment in this study. The maximum power density of 1410.2 mW/m(2) was obtained with a current density of 4947.9 mA/m(2) when the high strength molasses wastewater with chemical oxygen demand (COD) of 127,500 mg/l was employed as the influent. The total COD, sulfate and color removal efficiencies of the proposed system were achieved of 53.2%, 52.7% and 41.1%, respectively. Each unit of this system had respective function and performed well when integrated together. The UASB reactor unit was mainly responsible for COD removal and sulfate reduction, while the MFC unit was used for the oxidation of generated sulfide with electricity generation. The BAF unit dominated color removal and phenol derivatives degradation. This study is a beneficial attempt to combine MFC technology with conventional anaerobic-aerobic processes for actual wastewater treatment. (C) 2009 Elsevier Ltd. All rights reserved.