Contaminant immobilization through heterogeneous carbonate growth at mineral/water and mineral/microbe interfaces
EMSL Project ID
50820
Abstract
The presence of mineral surfaces and of microorganisms significantly impacts the nature and composition of mineral phases formed in biogeochemical systems. Despite the importance of these heterogeneous reactions, predictions of the fate of biogeochemical systems relevant to DOE often rely solely on bulk thermodynamics due to a lack of robust theoretical tools that can predict heterogeneous mineral nucleation and growth. Our understanding of the molecular-scale processes of contaminant immobilization in mineral phases formed at mineral/water and mineral/microbe interfaces remains limited as a result. The long-term vision of this research is therefore to develop a quantitative understanding of contaminant immobilization in mineral precipitates at mineral/water and mineral/microbe interfaces to enable accurate predictions of the fate of metal contaminants in heterogeneous biogeochemical systems.Immobilization of divalent metal cations in carbonate precipitates formed at carbonate, silicate, and bacterial cell surfaces will be used as a model system due to the ubiquitous presence of carbonates in and major impact on soils, marine sediments, and suspended matter in fresh and sea waters. A combination of state-of-the-art experimental capabilities and molecular simulations will be deployed to overcome current limitations and quantify the effects of several thermodynamic and kinetic controlling factors (kinetics of water exchange, structural mismatch, and ability to form amorphous intermediates). Specifically, this research will investigate: (1) the effects of the kinetics of water exchange around cations on their ability to incorporate and intermix in epitaxial carbonate coatings; (2) any potential correlation between the ionic radius of metal contaminants and their ability to form carbonate coatings on non-isostructural mineral substrates; and (3) any enhancement in metal contaminant incorporation afforded by the formation of an amorphous calcium carbonate intermediate during microbially-induced calcite (CaCO3) precipitation.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2019-10-01
End Date
2021-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
Kerisit S.N., and M.P. Prange. 2019. "Ab Initio Molecular Dynamics Simulation of Divalent Metal Cation Incorporation in Calcite: Implications for Interpreting X-Ray Absorption Spectroscopy Data." ACS Earth and Space Chemistry 3, no. 11:2582-2592. PNNL-SA-146667. doi:10.1021/acsearthspacechem.9b00247
Kerisit S.N., and M.P. Prange. 2020. "Ab initio molecular dynamics simulation of Nd3+ incorporation in calcite." Chemical Geology 534. PNNL-SA-147075. doi:10.1016/j.chemgeo.2019.119460
Ling F.T., J.E. Post, P.J. Heaney, C.M. Santelli, E.S. Ilton, W.D. Burgos, and A.W. Rose. 2020. "A multi-method characterization of natural terrestrial birnessites." The American Mineralogist 105, no. 6:833-847. PNNL-SA-149385. doi:10.2138/am-2020-7303