Enhancing operating capacity of microbial fuel cells by using low-cost electrodes and multi anode-cathode connections in a membrane-less configuration

Abstract

Air-cathode microbial fuel cells (MFCs) are common configurations for real scales, especially wastewater treatment due to direct access to oxygen and scaling up capability. Herein, a single-chamber MFC (SCMFC) was used. The fabrication of graphite paint/stainless steel mesh (GP/SSM) anodes in sinusoidal geometry increased the electrode surface area per unit volume of the SCMFC and made it possible to utilize the maximum reactor capacity. Under batch mode, the SCMFC produced 1597 mW/m3 using six anodes and eight air-cathodes, and the maximum COD removal was obtained 93.22% and 93.54% in the second and fourth batches, respectively. Moreover, the effect of electrode surface area on power output was investigated; the power density became 2-fold when the air-cathodes’ surface area increased eight times, and increasing the anode surface area improved the power production per unit volume. The COD removal of 82.14% with 20.46% columbic efficiency was achieved after 72 h of continuous operation.