Geochemistry/Biogeochemistry and Subsurface Science
Research in this science theme addresses some of the most challenging issues confronting the nation, including the safe and cost-effective management of environmental pollutants, green house gases, and the safe disposal of nuclear waste. Solutions to these issues are essential for both engineering a safe and sustainable future and addressing legacy contamination challenges.
Phenomena as diverse as CO2 exchange with the terrestrial ecosystem and contaminant transport in the subsurface are the result of molecular-level processes that control their transport and fate. The development of predictive models of these phenomena necessitates both development of mechanistic understanding of these processes and accurate representation in models across multiple scales. These processes occur in complex chemically and physically heterogeneous terrestrial and subsurface environments where processes can interact in unexpected ways. Understanding the structure, chemistry, and nanoscale geometric properties of carbon, micronutrients and contaminants at the water/mineral, root/microbe and microbe/mineral interfaces as well as transport phenomenon at the pore and intermediate scale is critical to development of accurate predictive models of chemical reactivity and its spatial distribution at larger scale.
As a result, molecular-level studies of interfacial geochemistry and biogeochemical reactions, and pore- to intermediate-scale transport phenomenon have been an active area of research by EMSL users and staff scientists for more than a decade. Unraveling these phenomena at the molecular level, using an integrated experimental and computational approach, to determine their impact on elemental, nutrient, and contaminant migration and transformation is a key objective of this science theme.
This science theme will focus EMSL's scientific resources on the following key topical areas:
- Interdependency between geochemical processes and microbial, fungal and plant communities. This topic area is focused on the need to understand how microbial, fungal, and plant community structure and function vary in space and time and how such changes impact the geochemical conditions such as redox, pH, mineral reactivity, nutrient concentrations in microenvironments.
- Geochemical Processes. This topic area emphasizes the development of a fundamental understanding of geochemical processes and reaction rates that occur at or near mineral surfaces, including aqueous solution chemistry, mineral-fluid interactions, and surface complexes, using an integrated experiment, theory, modeling and simulation approach.
- Subsurface reactive transport. This topic area is focused on the coupling of pore- and intermediate-scale hydrologic processes and fluids with molecular-scale phenomena such as mineral growth and dissolution, microbial and fungal growth and biofilm formation, and colloid aggregation and transport that impact the fate and transport of elements, contaminants, nutrients, and other chemicals at field-relevant scales for the development of reactive transport codes.
- Biogeochemical signatures and sensors for in situ characterization. This topic area is focused on the development of in situ signatures and sensors to ascertain geochemical and biogeochemical conditions in terrestrial and subsurface microenvironments and their applicability to assess field-scale conditions.
In addition, EMSLs annual Call for Proposals solicits ideas to address an announced set of focused topics within each of these key areas.
EMSL's focus, capabilities, and staff expertise have led to a molecular-level understanding of complex biogeochemical processes in the subsurface. These scientific insights have led to more efficient and cost effective contaminant remediation efforts across the DOE complex. EMSL is expanding its focus to include research in the terrestrial ecosystem by creating advanced capabilities to determine the chemical form of natural organic matter in soil and groundwater; developing a mechanistic understanding of the carbon cycle in the terrestrial ecosystem; and improving the linkage of fundamental studies of molecular geochemistry/biogeochemistry to field-scale modeling and predictive studies.
All Related Science Highlights Related Science Highlights
- Sulfide and iron work together to reveal a new path for radionuclide sequestration (Sulfur cleans up)
- EMSL tools reveal morphology, growth mechanisms of precipitates from scCO2 storage (Rods and rosettes)
- New bacteria, potential carbon cycling, bioremediation roles reported in Science (Brand new genes)
- New knowledge about fungi biochemistry opens doors for better bioremediation options (Fungi clean up)
- New geometric method developed for evaluating metal nanoparticles on tubular structures (Viewing the Tube in 3D)