Advances in Understanding Electron Transfer Kinetics at Environmental Interfaces
EMSL Project ID
25711
Abstract
This EMSL user proposal requests a continuation of EMSL access for a BER funded Environmental Molecular Sciences Institute (EMSI) project led by Dr. Rosso at PNNL. This project constitutes the PNNL component of the Stanford EMSI led by Dr. Gordon Brown entitled "Chemical and Biological Interactions at Environmental Interfaces". For this continuation we request "Standard Access" under the Geochemistry/Biogeochemistry and Subsurface Science Theme. The main scientific focus of the Stanford EMSI is on chemical and microbiological interactions at solid-aqueous solution interfaces of relevance to Earths near-surface environment where natural waters, natural organic matter, and biological organisms interact with natural solids and environmental contaminants. Surface chemical processes are of vital environmental concern because they control the chemical weathering of minerals, corrosion, the development of soils, water quality, colloid stability, contaminant and nutrient sequestration and release, soil rheological properties, acid mine drainage, the respiratory cycle of microorganisms, and the biogeochemical cycling of elements. Under the proposed new term, we will focus our efforts on two scientific questions. The first involves U(VI) reduction by Fe(II) in homogeneous aqueous solution. The rate of electron transfer in this system depends on mechanisms of forming an encounter complex and the rate of electron transfer within the encounter complex. A question we will pursue is can this encounter complex be experimentally detected in solution, and, if so, what is the rate of reduction in this complex? The second question we will address pertains to electron transfer across the cytochrome-oxide interface as a central process in the respiratory action of dissimilatory metal reducing microorganisms such as Shewanella oneidensis. We propose to address the question of can a molecular model describing the rate of elementary electron transfer steps across the interface be constructed for direct comparison with experimental measurements? The proposed experimental and computational work is directly centered on the Geochemistry/Biogeochemistry and Subsurface Science EMSL theme.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2007-05-24
End Date
2010-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Gorby YA, JS McLean, AA Korenevsky, KM Rosso, MY El-Naggar, and TJ Beveridge. 2008. "Redox-Reactive Membrane Vesicles produced by Shewanella." Geobiology 6(3):232-241. doi:10.1111/j.1472-4669.2008.00158.x