(gc3563)Molecular Computational Studies In Environmental Chemistry, Geochemistry, and Biogeochemistry
EMSL Project ID
3563
Abstract
Addressing the overwhelming environmental cleanup problems facing the Department of Energy?s nuclear production sites as well as other polluted sites in the nation is hampered by a lack of knowledge about many of the complex physical and chemical processes that can occur in the subsurface. High-performance computational molecular modeling of several areas of environmental chemistry, geochemistry, and biogeochemistry could significantly improve this situation by providing the development of a fundamental chemical understanding of many complex environmental and geochemical processes. Our proposed effort consists of a series of targeted molecular level simulations in key areas of environmental chemistry, geochemistry, and biogeochemistry. These simulations will be defined in five areas: chemistry of organochlorine compounds, aqueous speciation of metal ions and chelates, redox reactions at iron oxide surfaces, nanoparticle stability and oriented aggregation, and microbial-mineral interactions. By addressing these five different, but computationally related, areas it becomes possible to assemble a team of investigators with the necessary expertise in high performance computing and molecular simulation, as well as in environmental chemistry, geochemistry, and biogeochemistry to make continued and sustained progress in each area. Within each defined area, specific environmental chemisty, geochemistry and biogeochemistry issues are targeted. The summaries of each area are:Chemistry of organochlorine compounds: Characterize competing reaction mechanisms of the dechlorination of carbon tetrachloride and other organochlorine compounds in the subsurface environments
Aqueous speciation of metal ions and chelates: Understanding aqueous speciation under the unusual conditions, particularily highly basic conditions, where anions (silicate species) can show high solubilities and form complex polynuclear-metal complexes, or at high temperatures and pressures where a decreasing dielectric constant results in ever-increasing cation-anion associations.
Redox reactions at iron oxide surfaces: Studying the III/II valence interchange of iron (small polaron mobility) in iron oxides such as hematite (a?Fe2O3) and goethite (a?FeOOH)
Nanoparticle stability and oriented aggregation: identifying the factors governing the surface chemistry of iron oxide and oxyhydroxide nanoparticles in aqueous solution using large-scale molecular dynamics calculations.
Microbial surface mediated processes: the effects of lipopolysacchardies present on gram-negative bacteria.
By understanding on a fundamental basis these key issues, it is anticipated that the impacts of this research will be extendable to a wide range of environmental and geochemical. Taken in total such an effort truly represents a ?Grand Challenge? in molecular environmental chemistry, geochemistry, and biogeochemistry.
Project Details
Project type
Capability Research
Start Date
2003-10-01
End Date
2006-10-08
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Large Molecules as Models for Small Particles in Aqueous Geochemistry Research
Casey WH, JR Rustad, D Banerjee, and G Furrer. 2005. "Large Molecules as Models for Small Particles in Aqueous Geochemistry Research." Journal of Nanoparticle Research 7(4-5):377-387. doi:10.1007/s11051-005-4718-8
Electron transfer in environmental systems: a frontier for theoretical chemistry
Rosso KM, and M Dupuis. 2006. "Electron Transfer in Environmental Systems: A Frontier for Theoretical Chemistry ." Theoretical Chemistry Accounts 116(1-3):124-136. doi:10.1007/s00214-005-0016-x
Molecular dynamics simulation of the titration of polyoxocations in aqueous solution
Rustad JR. 2005. "Molecular Dynamics Simulation of the Titration of Polyoxocations in Aqueous Solution." Geochimica et Cosmochimica Acta 69(18):4397-4410. doi:10.1016/j.gca.2005.05.007
A Molecular Dynamics Investigation of Hydrolytic Polymerization in a Metal−Hydroxide Gel
Rustad JR, and WH Casey. 2006. "A Molecular Dynamics Investigation of Hydrolytic Polymerization in a Metal-Hydroxide Gel." Journal of Physical Chemistry B 110(14):7107-7112. doi:10.1021/jp054379t
A molecular dynamics investigation of the titration of a trivalent aqueous ion
Rustad JR, and WH Casey. 2006. "A Molecular Dynamics Investigation of the Titration of a Trivalent Aqueous Ion." Theoretical Chemistry Accounts 115(2):136-144. doi:10.1007/s00214-005-0048-2
Oxygen-exchange pathways in aluminum polyoxocations
Rustad JR, JS Loring, and WH Casey. 2004. "Oxygen-exchange Pathways in Aluminum Polyoxocations." Geochimica et Cosmochimica Acta 68(14):3011-3017. doi:10.1016/j.gca.2003.12.021
Modeling Water Exchange on an Aluminum Polyoxocation
Stack AG, JR Rustad, and WH Casey. 2005. "Modeling Water Exchange on an Aluminum Polyoxocation." Journal of Physical Chemistry B 109(50):23771-23775. doi:10.1021/jp0530505
A simple model for the effect of hydration on the distribution of ferrous iron at reduced hematite (012) surfaces
Wang J, and JR Rustad. 2006. "A Simple Model for the Effect of Hydration on the Distribution of Ferrous Iron at Reduced Hematite (012) Surfaces." Geochimica et Cosmochimica Acta 70(21):5285-5292. doi:10.1016/j.gca.2006.08.022