Comparison of performance and ionic concentration gradient of two-chamber microbial fuel cell using ceramic membrane (CM) and cation exchange membrane (CEM) as separators

Abstract

Ceramic membranes (CMs) with different pore sizes (0.14 mm CM1, 150 kDa CM2 and 5 kDa CM3) were tested as separators in two-chamber microbial fuel cells (MFCs). The performance and ionic gradient concentration of MFCs using CMs were compared with that of cation exchange membrane (CEM), Nafion 117. MFC with CMs exhibited a higher performance than that of CEM under batch operation. The highest power density of 1790 +/- 60 mW/m(2), columbic efficiency (CE) of 41 +/- 10% and internal resistance of 102 +/- 13 U were obtained for MFC with CM3 under batch mode operation. The highest power density, columbic efficiency and internal resistance of MFC with CEM were found to be 1225 +/- 20 mW/m(2), 21 +/- 1% and 400 +/- 10 U, respectively. The highest performance of MFC with CM3 was expected due to a higher porosity of CM3 (13.8%) compared with that of CM1 (11.0%) and CM2 (11.05%). MFCs operated with catholyte containing salt solution, phosphate buffer basal medium without carbon source and yeast extract (PBBM-SA), generated lower current than with phosphate buffer (PB) as catholyte. This difference was more significant in the MFCs with the CEM Nafion 117 than with ceramic membranes. The nonselective porous ceramic membranes improved the diffusion of protons in the presence of other high concentration cations and resulted in MFC with higher performance. Hence, the porous ceramic membrane is a potential candidate separator for the development of commercial scale MFCs. (C) 2017 Elsevier Ltd. All rights reserved.