Enhancing microbial fuel cell performance using eco-friendly magnesium and calcium micronutrients in real food waste substrate

Abstract

Microbial fuel cells (MFCs) represent an avenue for harnessing renewable energy from waste substrates; however, their capacity for electrical energy generation remains limited. Therefore, numerous investigations have sought to improve this capability through various modifications, including alterations to the anode, cathode, and chamber configuration. The supplementation of metal ions, such as Cr, Co, and Cu, as micronutrients has emerged as an effective method to improve MFC performance. This study aimed to investigate the effects of Mg²⁺ and Ca²⁺ as eco-friendly micronutrients for accelerating electrogenic bacteria growth and improving the generation of electricity in the MFC. These findings revealed a significant improvement in MFC performance following the addition of these metal ions, attributed to their acceleration of Shewanella oneidensis MR-1 growth. Mg²⁺ succeeds in generating a maximum voltage of 100 mV at 1 and 2 μM Mg²⁺ (3 times higher than Ca²⁺), a current density of 25,000 mA/m² (18 times higher than Ca²⁺), and a power density of 1400 mW/m² (2.5 times higher than Ca²⁺). This finding proves that Mg²⁺ has a positive impact on generating electricity in MFC. Even at minimal concentrations, this study observed increased electric power density.