Geochemistry/Biogeochemistry and Subsurface Science Theme provides studying reaction mechanisms at the mineral-water, microbe-mineral, and fluid-fluid interfaces at the molecular scale and understanding the effect of these mechanisms on the fate and transport of contaminants.

One of the most challenging and pressing issues confronting DOE and the nation is the safe and cost-effective management of environmental pollutants and the remediation of hazardous waste sites. DOE is responsible for managing some 40 million cubic meters of contaminated soils and 1.7 trillion gallons of contaminated groundwater. Across the United States, thousands of Superfund sites exist with various levels and types of contamination (e.g., organic materials, heavy metals, inorganic materials, radionuclides).

Molecular level processes, such as aqueous complexation, adsorption to different mineral phases, or microbial reduction of redox active metals, often control the transport and fate of contaminants in the environment. These processes occur in complicated subsurface environments that are chemically and physically heterogeneous. Understanding the structure, chemistry, and nano-scale geometric properties of the mineral/water and microbe/mineral interfaces are therefore key aspects of developing a mechanistic understanding of contaminant transport. As a result molecular level studies of interfacial geochemistry and biogeochemical reactions have been an active area of research for more than a decade. Unraveling these phenomena at the molecular level and determining their impact on contaminant migration and transformation in the environment is a key objective of this science theme area.

This science theme will focus EMSL's scientific resources on the following key topical areas:

Interfacial molecular geochemistry and biogeochemistry

Understanding the chemistry of radionuclides in the subsurface

Understanding the fact and transport of chemical and microbial species in the subsurface.

Research in the area of biogeochemistry and subsurface science is well established in EMSL. We propose to build on our strength in that area by focusing on key scientific questions/challenges in the area of molecular geochemistry and biogeochemistry, linking Subsurface Flow and Transport Experimental Laboratory capabilities to molecular-science capabilities, and gaining better access to use of radioactive materials.

Vasil Sidorov on September 12, 2009  E-mail: sidorovvasil@gmail.com

From PNNL`s Reports