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MICROSCALE METABOLIC, REDOX AND ABIOTIC REACTIONS IN HANFORD 300 AREA SUBSURFACE SEDIMENTS


EMSL Project ID
32594

Abstract

This proposal is the NMR component of a funded DOE/ERSP program project in which we proposed to use the Hanford 300 Area as a site for identifying microscale metabolic, abiotic and redox reactions in the subsurface and in the microbial communities. We plan to measure metabolites, redox chemicals and uranyl concentrations at the microscale using nuclear magnetic resonance (NMR) spectroscopy and various microelectrodes (UO22+, H2S, O2, SO4-, NO3-, Eh and pH). In practice, uranium transformation from the liquid phase to the solid phase occurs in established communities of cells growing on mineral surfaces. Development of bacterial communities on surfaces results in dense, highly metabolically active cells along with extracellular polymeric substances (EPS). A recent discovery showed that precipitated uranium nanoparticles can associate with the extracellular matrix material, which supports the importance of these community processes and the potential increased reactive potential of EPS. Hence, microbial processes and redox and abiotic reactions which operate at the microscale are critical to understanding factors controlling the macroscopic fate and transport of contaminants in the subsurface.
This proposal addresses the development and implementation of biofilm based methods to understand uranium mobilitiy in subsurface biofilms. A NMR compatible biofilm reactor will be used to characterize metabolite concentrations (lactate, acetate and pyruvate), alternative electron acceptor concentration (fumarate) with/without uranium. NMR data will be combined the microsensors data produced at Washington State University to determine microscale factors affecting uranium mobility and the data will be used further biofilm modeling.

Project Details

Project type
Exploratory Research
Start Date
2009-05-21
End Date
2010-05-23
Status
Closed

Team

Principal Investigator

Haluk Beyenal
Institution
Washington State University

Team Members

Bin Cao
Institution
Nanyang Technological University

Ryan Renslow
Institution
Pacific Northwest National Laboratory

Jeffrey Mclean
Institution
University of Washington

Paul Majors
Institution
Washington State University

James Fredrickson
Institution
Pacific Northwest National Laboratory