BACKGROUNDSulfonated poly (ether ether ketone) (SPEEK) membranes and their modifications are viewed as arguably the most promising in microbial fuel cell (MFC) applications due to their non-fluorinated base, superior chemical stability, and lower costs compared with Nafion membranes. In this work, SPEEK membranes with different degrees of sulfonation (DSs) (60% to 76%) and blended with charged surface modifying macromolecule (cSMM) were used as electrolytes in an MFC for simultaneous electricity generation and wastewater treatment. RESULTSPerformance evaluation of newly fabricated membranes was carried out and was compared with that of Nafion 117. The MFC with SPEEK76/cSMM generated about 16.5% higher maximum power density (172.1 mW m(-2)) than that with Nafion 117 (143.7 mW m(-2)). In addition, the SPEEK76/cSMM exhibited the highest coulombic efficiency (CE) of 17.6%, which was 21.6% higher than that of Nafion 117 (13.8%). Chemical oxygen demand (COD) removal of all characterized membranes was above 80% in our particular MFC. CONCLUSIONMFC is a suitable method for simultaneous wastewater treatment and electricity generation. SPEEK76/cSMM is a promising membrane to be applied in MFC. (c) 2014 Society of Chemical Industry