Development of Lab-Scale Microbial Fuel Cell-Based In-situ Electrokinetic Soil Remediation for Arctic Conditions (Phase I)

Status: Completed

Funding Agency: Department of War (DOW)

Abstract: 

Heavy metal contamination is an ongoing problem in the Arctic, affecting its soils and water bodies. These metals enter the environment through human activities such as mining and past military operations. Over time, they build up in the ecosystem and pose a risk to the environment and human health. Permafrost thawing during high temperatures drives this contamination process, where heavy metals that were previously locked away in frozen ground are released into the environment. Most conventional cleanup methods are either expensive to deploy at remote sites or depend on an external power source, which makes them impractical for the Arctic. This creates a need for a self-powered, in-situ treatment that works in cold and remote conditions without much infrastructure. This study developed and tested a lab-scale system that couples a microbial fuel cell (MFC) with electrokinetic remediation (EKR) to remove these metals from contaminated soil using electrical energy generated by microbial activity. Experiments were conducted in three-chamber reactors at ambient (25°C) and cold (5°C) temperatures, from proof-of-concept to lead (Pb) and arsenic (As) removal experiments. Electrode materials were also evaluated to assess their influence on system performance. The system removed 86.93% of Pb at 25°C and 77.86% at 25°C, and 96.87% of As at 25°C and 85.16% at 25°C. Carbon felt cathodes outperformed platinum cathodes by about 38-fold in peak power and stayed active under the cold conditions. Across all experiments, pH was found to be a critical factor that affected metal pathway and removal efficiency at both temperatures. The results support MFC-EKR as a viable self-powered option for treating contaminated soils at remote and cold-region defense sites.

Investigators: Dr. Jagadish Torlapati, PhD.

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