Application of PVA–PDDA polymer electrolyte composite anion exchange membrane separator for improved bioelectricity production in a single chambered microbial fuel cell

• KOH doped PVA–PDDA used as separator in MFC.
• High current output in PVA–PDDA commercial Ralex AEM and PVA based CEM.
• PVA–PDDA exhibited high conductivity and antifouling activity.
• Aqueous PVA solution as low cost binder was found effective.

The present study deals with the preparation and characterization of low cost custom made KOH doped polyvinyl alcohol (PVA)–polydiallyldimethylammonium chloride (PDDA) anion exchange membranes (AEM). The synthesized membrane was used as a separator in single chambered microbial fuel cells (sMFCs). The membranes were characterized in terms of proton conductivity, oxygen diffusion, and ion exchange ability. The performance of sMFCs with newly prepared AEM separator was evaluated with respect to operating voltage and COD removal. Higher volumetric power density was achieved in case of PVA–PDDA composite membrane as compared to PVA–STA cation exchange membrane and commercial Ralex AEM mainly due to low internal resistance and less biofouling. The effect of PDDA content in composite membrane was evaluated in terms of current density and coulombic efficiency. The PDDA blending in membrane had significant influence on the reduction of impedance (improvement in anionic conductivity) and biofouling. A maximum power density of 6.68 W/m3 was obtained when Shewanella putrefaciens was used in lactate medium fed sMFC equipped with PVA–PDDA based MCA. Power output increased with membrane cathode assembly (MCA) surface area. An optimized quantity (0.5 mg/cm2) of 1% (w/v) PVA solution was found to be effective as suitable binder. PVA–PDDA composite membrane exhibited as a suitable alternative to the costly membrane commonly used in the MFC.

Figure optionsDownload as PowerPoint slide