Abstract

Microbial Fuel Cells (MFCs) are promising bio electrochemical systems capable of simultaneously treating wastewater and generating renewable bioelectricity. Their performance is governed by microbial metabolism, electrode properties, ionic transport, and environmental conditions. Despite extensive global research, the electro genic potential of Iraqi aquatic ecosystems as native sources of electro active microorganisms remains largely unexplored. This study evaluates bioelectricity generation using contaminated water and sediment collected from five environmental sites in Iraq, with emphasis on physicochemical influences and temporal voltage behavior. A dual-chamber MFC was constructed using an aluminum anode, copper cathode, potassium permanganate catholyte (0.3%), and a cotton-wick proton-conducting bridge. Voltage output, pH, temperature, electrical conductivity (EC), and total dissolved solids (TDS) were monitored over five days. Descriptive statistics, temporal trend analysis, and correlation analysis were performed, alongside mathematical modeling of voltage generation, internal resistance, power output, and Columbic efficiency. Initial voltage outputs ranged from 0.45 to 0.56 V, increasing to a maximum of 0.66 V after 48 h due to anodic biofilm maturation. Hilla Drainage and Bahr Al-Najaf exhibited the highest electrogenic activity, while Hilla Lake showed the lowest performance. EC and TDS displayed moderate to strong correlations with voltage output (r ≈ 0.65–0.82), highlighting the role of ionic transport. Mathematical modeling confirmed a reduction in internal resistance with increasing biofilm density. Overall, the results demonstrate that native Iraqi microbial communities possess strong electro active capabilities, supporting the feasibility of MFCs as low-cost, self-sustaining energy systems. Future work should focus on nanoparticle-enhanced electrodes, improved membranes, and system scaling for wastewater treatment and bio sensing applications.