The effect of various system parameters such as wastewater Chemical Oxygen Demand (COD) concentration, pH, conductivity, membrane size and thickness on efficient energy production using mixed isolated culture from the distillery wastewater in the MFC was studied. The power density increased with increase in the anolyte pH from 6 to 8. The peak power density and COD removal efficiency was observed as 63.8 +/- 0.65 mW/m(2) and 63.5 +/- 1.5% at pH 8, respectively. The MFC performance increased with increasing COD concentration (800-3200 mg/l), conductivity (1.1-9.7 mS/cm) and membrane area (8-24 cm(2)). The MFC operating with wastewater COD concentration of 3200 mg/l and its conductivity of 9.7 mS/cm produced the highest power density of 202 +/- 6 mW/m(2) with a corresponding current density of 412 +/- 12 mA/m(2). The results showed that the efficient electricity generation and simultaneous treatment of distillery wastewater can be attained in the MFC. (C) 2015 Elsevier Ltd. All rights reserved.