From Contaminant to Current: Enhancing Large Scale Microbial Fuel Cells for Groundwater Remediation

The demand for energy-efficient groundwater remediation technologies has driven interest in Microbial Fuel Cells (MFCs) as a dual solution for contaminant degradation and energy production. Although laboratory-scale MFC studies have explored the interaction between microorganisms and electrode materials, the scalability of these systems for real-world applications in heterogeneous environments remains understudied. This study presents a highly controlled and monitored field-scale MFC design aimed at optimizing power output within a 1 x 1 x 6 m flow-through tank filled with porous medium and contaminated with diesel fuel. The system utilizes stainless steel electrodes with and without activated carbon filling and anaerobic bacteria to convert diesel into electrical energy through bioelectrochemical processes.

Experimental parameters—including water conductivity, flow rate, and dissolved oxygen—were held constant, while electrode material, spacing, and external resistance were systematically varied to assess their effects on power enhancement. Stainless steel electrodes emerged as the most efficient, with activated carbon reaching stable power output faster than other materials. The optimized configuration generated a stable power output of 1.1 W, coupled with an estimated degradation of 800 mg of diesel over 173 days. Additionally, microbial analysis indicated that exoelectrogenic bacteria adapted to sustain higher power generation without altering environmental conditions adversely.

This work demonstrates that electrode material and spatial arrangement are key to improving MFC power output and therefore remediation efficiencies in field-scale settings. The results advance the potential of MFCs as a sustainable technology for groundwater remediation and renewable energy generation, bridging the gap between lab-scale experimentation and practical environmental applications.