HR: 16:20h
AN: NS44A-01 INVITED     [Abstracts]
TI: Ocean Microbial Fuel Cell: Power Source and Research Tool for Studying Marine Biogeochemistry
AU: * Reimers, C E
EM: creimers@coas.oregonstate.edu
AF: Oregon State University, College of Oceanic and Atmospheric Sciences Hatfield Marine Science Center, Newport, OR 97365, United States
AU: Girguis, P
EM: pgirguis@oeb.harvard.edu
AF: Harvard University, Biological Labs 16 Divinity Ave , Cambridge, MA 02138, United States
AU: Westall, J C
EM: john.westall@coas.oregonstate.edu
AF: Oregon State University, Department of Chemistry 153 Gilbert Hall, Corvallis, OR 97331, United States
AU: Nielsen, M E
EM: mnielsen@coas.oregonstate.edu
AF: Oregon State University, College of Oceanic and Atmospheric Sciences Hatfield Marine Science Center, Newport, OR 97365, United States
AB: Ocean microbial fuel cells (OMFCs) are devices capable of producing modest levels of electrical power. The cells are ultimately driven by the oxidation of marine organic matter at the anode and reduction of dissolved oxygen at the cathode, but microbial transformations and electrochemically active intermediates play important roles in the overall process of electricity generation. By separating the factors that affect the performance of OMFCs into components of an equivalent circuit and manipulating these factors in laboratory and field experiments, we are gaining new insight into how specific redox reactions, sources of organic matter, and mass transport at small and intermediate scales may enrich environments with certain groups of microorganisms that in turn regulate anaerobic organic matter degradation. This talk will illustrate these relationships with the results from at least four experiments in which either fresh plankton, or substrates within continental margin sediments, fuelled the OMFCs. In each example, reduced sulfur compounds were found to be major electron carriers to the fuel cell anode. These intermediates came from a variety of sources including sulfide generated from sulfate reduction in mixed solutions surrounding the electrode, sulfide generated distally but transported by pore-water diffusion and advection, iron monosulfides and pyrite present is a sediment matrix centimeters from the electrode, and sulfide or polysulfide produced within an electrode biofilm. To illustrate a practical application of an OMFC, we are currently constructing a benthic cell that will power a sonic receiver in a network of underwater sensors. The form of this OMFC resembles a benthic chamber with a footprint of one square meter. It should be capable of supplying electrical power and regulating its output for years to decades.
DE: 0408 Benthic processes (4804)
DE: 0460 Marine systems (4800)
DE: 0471 Oxidation/reduction reactions (4851)
DE: 4262 Ocean observing systems
DE: 4806 Carbon cycling (0428)
SC: Near-Surface Geophysics [NS]
MN: 2007 Joint Assembly