Evaluation of Low-Cost Separators for Increased Power Generation in Single Chamber Microbial Fuel Cells with Membrane Electrode Assembly

We compared novel size-selective separators, namely the textile fabrics of polyphenylene sulfide (PPS) and sulfonated polyphenylene sulfide (S-PPS), and the nonwoven fabrics of polypropylene80 (PP 80) and PP 100, with commonly used ion exchange separators (Nafion 117 and cation exchange membane-7000; CMI-7000) in terms of power generation, oxygen diffusion, and biofilm formation in a single chamber microbial fuel cell. Size-selective separators exhibited more power generation than ion selective separators. MFC operation with size-selective separators generated power output ranging 0.407 to 0.591V (1000 Omega), whereas with Nafion it was 0.272 V. In polarization analysis, S-PPS resulted in the highest power density of 190 mW/m(2), whereas it was 24 mW/m(2) with Nafion-117. Size selective separators showed similar or higher proton conductivity than Nafion 117. Oxygen mass transfer coefficients of size-selective separators (K-O = 3.7 similar to 7.5x10(-5)) were lower or similar to Nafion (K-O = 7.5x10(-5)). Fourier-transform infrared spectroscopy and scanning electron microscopy analysis revealed that all separators (PP80, S-PPS, and Nafion) contained proteins or carbon chain compounds after 300-day operation, and however, Nafion 117 seems to be more susceptible to biofouling than the other separators.