Activated Carbon Electrodes for Bioenergy Production in Microbial Fuel Cells Using Synthetic Wastewater as Substrate

Abstract

The growing global energy demand drives the need to develop new clean energy technologies. In this context, microbial fuel cells (MFC) are one of the emerging technologies with great potential for eco-friendly energy generation; however, the correct choice of electrode material is a significant limitation in the optimal configuration of MFCs. Therefore, this research evaluated the efficiency of activated carbon (AC) anode electrodes for bioenergy production in MFC using synthetic wastewater as a substrate. Peak values of voltage (1120 ± 0.050 mV), current (4.64 ± 0.040 mA), power density (208.14 ± 17.15 mW/cm2), and current density (5.03 A/cm2) were generated, and the Rint obtained was 214.52 ± 5.22 Ω. The substrate was operated at pH values from 5.31 to 7.66, maximum ORP values (858 mV) were reached, and turbidity was reduced to 25.11 NTU. The SEM-EDS (scanning electron microscopy–energy-dispersive X-ray spectroscopy) analyses allowed us to observe the morphology and composition of the AC electrodes, revealing a predominance of O, C, Si, Al, Fe, K, and Ca. It is concluded that the AC electrodes have the potential to produce bioenergy at a laboratory by means of MFC.