Taxonomic profiling bacterial communities associated with a Bio-electrochemical System (BES) of contaminated groundwater at Belfast gasworks. Bio-Electrochemical Systems to Monitor Natural Attenuation around Groundwater Plumes

This study introduces a straightforward and cost-effective Bio-Electrochemical System (BES) design that can be easily retrofitted into a borehole. The design uses standard, transparent, reusable PVC bailers and graphite tape combined with Granular Activated Carbon (GAC) to create high surface area electrodes. These electrodes are connected across redox environments in nested boreholes through a wire and variable resistor setup. The amended electrodes were installed in pre-existing boreholes surrounding a groundwater plume at a gasworks site. Among all the BES locations tested, the BES at the plume fringe exhibited the highest electrical response and displayed significant variations in the differential abundance key bacterial and archaeal taxa between the anode and cathode electrodes. The other BES configurations in the plume center and uncontaminated groundwater showed little to no electrical response, suggesting minimal microbial activity. This straightforward approach enables informed decision-making regarding effectively monitoring, enhancing, or designing degradation strategies for groundwater plumes. It offers a valuable tool for understanding and managing contaminant degradation in such environments.