Low-cost earthen membrane: Inclusion of wood ash to improve performance of microbial fuel cell

Abstract

The membrane employed in microbial fuel cells (MFC) stands as a pivotal component, comprising more than half of the overall construction cost of the assembled MFC. This study introduces a novel earthen membrane, crafted by inclusion of wood ash in different weight ratios, providing a low-cost substitute to the conventional Nafion 117 membrane. Among the fabricated membranes, X3, engineered with red soil and 20% wood ash exhibits superior performance. The inclusion of wood ash enhances proton transport and mitigates oxygen diffusion into the anode, while also augmenting the ion exchange capacity of the fabricated membrane. The MFC equipped with the X3 membrane (MX3) demonstrates the highest COD removal (93.89±0.73%) and coulombic efficiency (66.10±2.53%). Notably, MX3 achieves a remarkable power density (Pmax: 1450.09±151.3 mW/m3), surpassing all other microbial fuel cells and marking a 9.8-fold increase in comparison to the control MFC. This study underscores the potential of the X3 membrane as a novel and economically viable alternate to Nafion 117 membrane.