Sorption Energy Maps of Clay Mineral Surfaces
A molecular-level understanding of mineral-water interactions is critical for the evaluation and prediction of the sorption properties of clay minerals that may be used in various chemical and radioactive waste disposal methods. Molecular models of metal sorption incorporate empirical energy force fields, based on molecular orbital calculations and spectroscopic data, that account for Coulombic, van der Waals attractive, and short-range repulsive energies. The summation of the non-bonded energy terms at equally-spaced grid points surrounding a mineral substrate provides a three dimensional potential energy grid. The energy map can be used to determine the optimal sorption sites of metal ions on the exposed surfaces of the mineral. By using this approach, we have evaluated the crystallographic and compositional control of metal sorption on the surfaces of kaolinite and illite. Estimates of the relative sorption energy and most stable sorption sites are derived based on a rigid ion approximation.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 9470
- Report Number(s):
- SAND99-1821J; TRN: US0103133
- Journal Information:
- American Mineralogist, Other Information: Submitted to American Mineralogist; PBD: 19 Jul 1999
- Country of Publication:
- United States
- Language:
- English
Similar Records
Oxyanion sorption and surface anion exchange by surfactant-modified clay minerals
Effects of cation and sorption site type on metal ion sorption on clay minerals: An x-ray absorption spectroscopic study