Boosting the performance of microbial fuel cells fed with partially treated buffalo milkmaid wastewater using modified CC/Co anodes: bacterial activity insights

Abstract

Microbial fuel cells (MFCs) have emerged as a promising technology for simultaneous wastewater treatment and electricity generation. However, enhancing the electrochemical performance of MFC anodes remains a critical challenge. This study investigated the modification of carbon cloth anodes with different concentrations of cobalt acetate (denoted as Co-Ac 3, Co-Ac 5, and Co-Ac 10) for improving MFC performance. The anodes were comprehensively characterized using XRD, SEM, and elemental mapping techniques. XRD analysis confirmed the successful synthesis of highly crystalline cubic cobalt nanoparticles on the carbon cloth substrate. The electrochemical evaluation demonstrated the superior performance of the Co-Ac 5 anode, achieving a maximum power density of 107.27 mW m⁻² and a remarkable 179-fold increase compared to the unmodified carbon cloth anode. The Co-Ac 5 anode also exhibited the highest chemical oxygen demand (COD) removal efficiency of 93.3%. SEM imaging revealed the formation of biofilms on the anode surface and provided insights into the size and distribution of cobalt nanoparticles. The optimal performance of the Co-Ac 5 anode was attributed to the presence of embedded cobalt nanoparticles within the carbon fibers, facilitating efficient extracellular electron transfer and promoting biofilm formation. This study highlights the importance of optimizing nanoparticle size and distribution on carbon cloth electrodes to balance catalytic activity, microbial interactions, and electrochemical performance in MFCs for wastewater treatment and energy recovery applications.