Environmental Remediation and Possible Use of Terrestrial Microbial Fuel Cells

Abstract

Many soils contain a wide number of organic and inorganic chemicals and potential toxic elements due to industrial, agricultural and numerous anthropogenic activities. The recovery of polluted sites is an urgent need to be addressed and the development of innovative remediation technologies, which exploit nature-based solutions, is strongly encouraged, in line with the new EU Circular Economy Action Plan. Terrestrial microbial fuel cells (TMFCs) can be a valuable tool for recovering soils polluted by various organic and inorganic contaminants. TMFCs benefit from capabilities of microbial biofilms developed on the electrodes, which use the terminals as catalysts for metabolic activities, including contaminant degradation. This process produces energy, thanks to conversion of chemical bond energy (stored in the bonds of organic compounds) into electrical ones. This work describes construction materials, remediation capabilities and technology of the TMFCs, reporting the last advances in TMFCs such as soil-based reactors or in combination with plants (plant microbial fuel cell (PMFC)). Some aspects related to microbiological activities for pollutant biodegradation, plant-microbial interactions, energy production, and fields of application will be shown. Finally, abiotic factors which can improve bioremediation activities are also considered. Furthermore, limitations and issues for large-scale applications, as well as for stacking and scaling-up are discussed.

Electroactive Bacteria in Natural Ecosystems and Their Applications in Microbial Fuel Cells for Bioremediation: A Review

“…For this reason, soil water content needs to be maintained constant to ensure anaerobic conditions at the anode and solute migration. In fact, when TMFCs are used for restoring contaminated soils or sediments, moisture needs to be close to its maximum water holding capacity [ 108 ]. For example, degradation of polycyclic aromatic hydrocarbons (PAH) [ 109 , 110 ] and other persistent organic compounds (POPs) [ 108 ] has been obtained in waterlogged soil.…”

“…In fact, when TMFCs are used for restoring contaminated soils or sediments, moisture needs to be close to its maximum water holding capacity [ 108 ]. For example, degradation of polycyclic aromatic hydrocarbons (PAH) [ 109 , 110 ] and other persistent organic compounds (POPs) [ 108 ] has been obtained in waterlogged soil. A recent work reports a petroleum refinery wastewater treatment with dual chamber MFCs, adding fermented milk as a co-substrate for improving hydrocarbon and COD removal.…”