Influence of organic carbon on molecular-scale biogeochemical cycling of iron, sulfur, and uranium in organic-rich aquifer sediments
EMSL Project ID
47860
Abstract
We propose a SLAC-EMSL collaboration to study the biogeochemical coupling of subsurface natural organic matter (NOM) to iron, sulfur, and uranium redox cycles in the subsurface at the DOE-BER funded Rifle, CO Integrated Field Research Challenge site. The Rifle site provides a model for other redox-active sites, as well as for uranium contamination in the Colorado River basin. The project will integrate unique, world-class EMSL capabilities in Fourier Transform Ion Cyclotron Resonance Mass Spectroscopy (FT-ICR MS) and high spatial resolution Secondary Ion Mass Spectrometry (NanoSIMS) with synchrotron-based Near Edge X-ray Absorption Fine Structure (NEXAFS) and Fourier Transform Infrared (FTIR) spectroscopy. By integrating these techniques, we will have the ability to analyze changes in NOM functional group structure, composition, and bonding and to link these changes to Fe, S, and U speciation in complex natural subsurface sediments. The overarching scientific question addressed is: What are the roles of specific functional groups in governing microbial decomposition of NOM and associated redox cycling of iron, sulfur, and uranium? This project is part of a DOE-BER funded effort at SLAC to understand NOM transport and sequestration in the subsurface and its impact on the biogeochemical cycling of micronutrients and toxicants. By focusing on the impact of carbon and microbial metabolism on pore-scale geochemical processes occurring in the immediate proximity of mineral surfaces, we will address two of the three topical areas in the geochemistry/biogeochemistry and subsurface science theme of this EMSL proposal solicitation. This project will help demonstrate the utility of these techniques for terrestrial and subsurface carbon research. It will serve as a basis for expanded collaboration between SLAC and EMSL in this research area. The project will provide new conceptual process models of terrestrial carbon dynamics that will inform the development of more realistic and accurate community earth system models.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2013-10-01
End Date
2014-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members