Effect of separator electrode assembly (SEA) design and mode of operation on the performance of continuous tubular microbial fuel cells (MFCs)

Three different innovative composition of nylon-cloth (NC), J-cloth (JC) and glass fiber (GF) were examined as separators in a tubular separator electrode assembly MFCs (SEA-MFCs) with a graphite granule bed anode and a simple carbon-cloth cathode. Three experiments were designed including horizontal MFC with co-current and counter-current inflows of anolyte and catholyte as well as vertical MFC with up-flow and co-current inflows to the MFC. The arrangement of NC-JC-GF was more effective with higher maximum power density (281.30 +/- 32.31 mW/m(2)) and lower internal resistance (562.09 Omega) compared to the other compositions. The power density was more improved as the hydraulic retention time (HRT) was decreased. The counter-current flow caused by higher species diffusion between the anode and cathode compartments compared to the co-current flow, so diminished the maximum power density significantly (270.60 +/- 29.53 to 70.48 +/- 5.65 mW/m(2)) and increased the internal resistance (614.71-1711.59 Omega). On the other hand, the horizontal operation showed better performance than the up-flow MFC. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.