Comparison of alternative membranes to replace high cost Nafion ones in microbial fuel cells

The aim of this work was to compare the performance of microbial fuel cell (MFC) fitted with alternative, low cost membranes (AMs). Lab scale single chamber MFCs were loaded with sulphate-reducing inocula as biocatalyst and leachate from dark fermentation of organic wastes as substrate. The MFCs were fitted with either hybrid membrane made of agar and Nafion MH, agar membrane M6 (6% agar), agar membrane M2 (2% agar) or the control Nafion 117 membrane (NF-117). We found that the internal resistances (R-int) were generally low for all the cells. The lowest Rint corresponded to alternative membranes M6 and MH with a value ca. 90 Omega. So, results of R-int tend to favour the AMs. The costs of these membranes were only 2.5-6% of the cost of the NF-117 one. However, the powers delivered by MFC fitted with AMs were 4-40% (weighed average 28%) of the power of the cell fitted with the conventional NF-117. In spite of the reduced power, the AMs still exhibited a higher Power/Cost ratio (0.9-4.4. mW/US$) than that of the NF membrane (0.23 mW/US$.) We should highlight that the AMs do not require the conditioning treatment with hazardous chemicals typical of NF-117. Therefore, there is another competitive edge of AMs in the form of avoided costs of chemicals and hazardous waste disposal. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.