(21b) Development of a Lab-Scale Microbial Fuel Cell for Electro-Kinetic Soil Remediation of Metals in Cold Regions

The heavy metal contamination of the environment in the Alaskan region has been on the rise primarily due to mining and other human activities. These metals can be released into the environment due to the thawing of the permafrost during the summer months, allowing them to flow into nearby streams and water bodies. This release of metals can contaminate the food chain and poses a significant health risk to the human population. Therefore, there is an urgent need for remediation strategies that can be adapted for cold regions and reduce the impact on the environment and human health.

This proposed study investigates the potential for heavy metal remediation using microbial fuel cell (MFC)-based electrokinetic remediation (EKR). This study will specifically examine the remediation of lead (Pb) since it is one of the significant contaminants within the Alaskan region (EPA, 2025). In addition, lead is considered second on the list of hazardous substances, according to the Agency for Toxic Substances and Disease Registry (ATSDR, 2022). We will conduct experiments in the laboratory using a triple-chamber MFC with an anode chamber, a cathode chamber, and a compartment for heavy metal-contaminated soil, with the dimensions of each chamber as 4 cm × 4 cm × 4 cm. The anode chamber of the MFC converts the chemical energy from the oxidation of hydrocarbons to generate electrons, which are essential for the MFC’s operation and subsequent metal remediation. The anaerobic bioremediation process allows free electrons to persist without an electron acceptor like oxygen. These free electrons are transported to the cathode chamber through a resistor, generating electricity. These free electrons also allow the metals in the contaminated soil to be transported to the cathode chamber for removal. In addition, these chambers are separated by proton-exchange membranes (PEM) to ensure the transfer of protons across to the cathode and prevent oxygen from entering the anode chamber. For this study, we used a graphite rod as the anode electrode, and sodium acetate was used as the substrate for anaerobic biodegradation. Furthermore, we used platinum as a cathode electrode, filling the cathode chamber with water.

The prototype MFC designed for this remediation process will use clean soil as a baseline to understand the potential for power generation. Subsequently, a full factorial design of experiments will be employed to assess the effects of temperature on Pb-contaminated soil, with experiments conducted at 5 °C and ambient temperature (around 20 °C). This will allow for the analysis of Pb remediation efficiency and power generation under conditions where microbial activity is limited as well as at optimal ranges for microbial activity. We anticipate that power generation and the remediation potential will be higher at ambient temperatures than at cold temperatures. Future studies will focus on optimizing the technology of MFC-based EKR for cold regions. This research has the potential to provide a technology for metal remediation that can be applied in cold regions while producing electricity.

REFERENCES

ATSDR. (2022). Support Document to the 2022 Substance Priority List A. f. T. S. a. D. Registry & D. o. T. a. H. H. Sciences.

EPA, U. S. (2025). TRI Explorer (2023 National Analysis Dataset (updated October 2024, released October 2024)). U.S EPA. Retrieved March 12 2025 from https://enviro.epa.gov/triexplorer/release_chem?p_view=STCH&trilib=TRIQ1&sort=_VIEW_&sort_fmt=1&state=02&county=All+counties&chemical=METAL_IND&industry=ALL&year=2023&tab_rpt=1&fld=