Turning Waste into Watt: Usage of natural biomass activated carbon-based anode and septic tank wastewater for Microbial Fuel Cell (MFC) based electricity generation

Activated carbons (ACs) are a highly desirable and challenging porous material. They are usually produced from biomass waste, which makes them a promising material for improved electrochemical capacitive efficiency. In the present study, we synthesized ACs from three various kinds of natural biomass wastes: orange peel (OP), loofah sponge (LS), and sugarcane bagasse (SB), using KOH treatment and the pyrolysis process. Various characterization studies, such as XRD, Raman spectroscopy, SEM with EDAX, BET, FTIR, and XPS, revealed the morphological and structural character of the developed ACs. The electrochemical studies appraised for ACs coated with copper (C) and aluminium (A) showed that orange peel activated carbon coated with copper foil (OPACC) has high surface area and lower internal resistance (Rs 18.13 Ω and Rct 28.68 Ω). We employed all produced electrodes as anode and septic tank wastewater (STWW) as anolyte in MFC application. Here we attained highest power density (163.84±0.5mW/m²), current density (372±2.3 mA/m²) and coulombic efficiency (49.33±1.01%) for OPACC electrode based MFC. The present study provides the first insight into comparing activated carbons produced from different biomass wastes and their performance as anodes in MFC for electricity production. These findings could benefit the future development of relevant renewable energy producers, potentially creating socially and morally acceptable biomass waste-based AC electrodes for MFCs.