Biofouling-focused assessment of a novel, cellulose-based ionogel membrane applied in a microbial fuel cell

In this work, a novel ionogel membrane was prepared on polyethersulfone physical support from the mixture of microcrystalline cellulose and [BMIM][Cl] (1-Butyl-3-methylimidazolium chloride) ionic liquid and used in a microbial fuel cell (MFC). The ionogel membrane was characterized in terms of its morphology, mass- (substrate, oxygen) and ion transfer features and compared to Nafion 115. The membranes were deployed in acetate-fed two-chamber MFC, where the MFC equipped with the ionogel membrane showed a Coulombic efficiency and peak current density of 49.4 % and 369 mA m−2, respectively. Through three weeks of experiments, the electrode and membrane biofouling layers were studied by 16S amplicon metagenomics and correspondence analysis. It turned out that a cellulose-degrading species, Clostridium termitidis was present with a relatively large, 23.2 % relative abundance on the surface of the ionogel membrane, which may have caused its deterioration and the consequent colonization of the cathodic compartment.