Analysis of polybenzimidazole and polyvinylpyrrolidone blend membranes as separating barrier in single chambered microbial fuel cells

• PBI and PVP Blend membranes have been analyzed in MFC as PEM.
• Mild alkali treatment resulted in PVP non re-dissolution from blends.
• Better performance resulted in 30:70 PBI/PVP blend membrane.
• EIS revealed lower resistance from 30:70 PBI/PVP blend membrane than others.
• Mixed firmicute consortium resulted in bioenergy generation from casted blends.

In present study, different blend compositions of polybenzimidazole (PBI) and polyvinylpyrrolidone (PVP) have been analyzed as polymer electrolyte membrane in single chambered MFCs. Four membranes namely, pure PBI, PBI/PVP 70:30, 50:50, and 30:70 blend ratios with increasing PVP content were casted, where the hygroscopic properties of the membranes were found enhanced with increasing PVP content. The membranes were characterized at room temperature (22 + 2 °C) with different ion exchange (IEC) and proton conductive capacities, where an IEC of 0.06 meq g−1, 0.15 meq g−1, 0.24 meq g−1 and 0.36 meq g−1 and proton conductivity of 2.5 × 10−4, 4.8 × 10−4, 9.36 × 10−4 and 1.2 × 10−3 S cm−1 were observed from pure PBI, PBI/PVP 70:30, 50:50, and 30:70 membranes respectively. As membrane electrode assemblies (MEA), the casted membranes were sandwiched in-between carbon cloths, where a maximum power and current density of 231.38 ± 12 mW m−2 and 1242 ± 62 mA m−2 were observed from 30:70 PBI/PVP fitted MFC, using mixed firmicutes as biocatalysts. A gross 84.36% COD removal from 30:70 PBI/PVP membrane indicated the added effect of PVP in blend composition with approximately 81% higher power over pure PBI membrane. The results indicate the potential efficacy of PBI/PVP blends as seperators in microbial fuel cell, for bio-energy conversion over pure PBI membrane.

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