Performance enhancement of an air-cathode microbial fuel cell with subsequent carbon source removal

Abstract

Microbial Fuel Cell (MFC) technology holds great promise for sustainability by simultaneously producing energy, recycling water, and degrading organic compounds. This study aimed to enhance MFC performance by introducing a biogenic air-cathode and marine bacteria. Marine bacteria were cultivated from estuarine seawater samples collected in Cape Town, South Africa, under optimal conditions (30 °C, pH 7). Additionally, the aircathode was modified with biogenic palladium (bio-Pd(0)) as a catalyst to improve MFC performance. The openloop cell potential was monitored every 24 h, and a maximum open-loop cell potential of 524.8 mV was recorded for the biogenic air-cathode compared to a value of 504.3mV for the control. The performance analysis of the MFC, which included recording closed-loop cell potential and assessing performance at various resistances, revealed that the biogenic cathode outperformed the control by reaching a peak power density of 4.94 mW/m3 . Performance analysis of the MFC at different concentrations of naphthalene (5 ppm, 10 ppm, 20 ppm) also revealed improved MFC performance with increasing naphthalene concentration up to 10 ppm but exhibited inhibitory effects at 20 ppm. Carbon source removal, assessed through chemical oxygen demand (COD) analysis, coincided with peak cell potential output. These findings highlighted the potential of MFC technology for wastewater treatment and energy generation.