Water Resources Research Act Program

Details for Project ID 2003DE24B

Accelerated Pollutant Biodegradation by Electrode Use

Institute: Delaware
Year Established: 2003 Start Date: 2003-06-01 End Date: 2004-02-28
Total Federal Funds: $1,500 Total Non-Federal Funds: $3,000

Principal Investigators: Steven Dentel

Project Summary: It has been shown by Bond et al. (2002) that in underwater sediments, the connection of anaerobic and aerobic layers by graphite electrode pairs increased the rate of biodegradation of acetate and benzoate while producing a measurable current through the electrodes. In their study, a biological population of anaerobic bacteria formed colonies around the surface of the deeper electrode (the anode). There is a lack of readily available electron acceptors (especially oxygen, the one that is most commonly used in aerobic environments) in an anaerobic environment but these microbes were apparently able to use the electrode as an electron acceptor. PCR analysis indicated them to be of a type that usually uses ferric iron ions (Fe3+) as an electron acceptor, converting it to Fe2+ while degrading organic materials. While the authors performed these experiments to model what could be done in marine sediments, they also stated that its success "suggests a strategy for promoting the bioremediation of organic sediments in the subsurface environment." What is remarkable is that the presence of the electrode pair actually accelerated the growth of the microorganisms responsible for biodegradation of the substrate. Thus, it is possible that the use of electrodes in this manner could offer some important benefits for wastewater treatment efficiency and remediation of contaminated groundwaters or sediments. The electrodes could be inserted with the lower portion bare, so that its surface would be available as an electrode at any depth needed. No chemical additions would be required. The process might even generate some electricity, and certainly would require no energy to operate. This would be beneficial for water resources by enabling subsurface contamination to be dealt with in an effective manner, preserving aquifer and other water quality for future generations.