Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-22T22:16:27.880Z Has data issue: false hasContentIssue false

Uranyl Surface Complexes in a Mixed-Charge Montmorillonite: Monte Carlo Computer Simulation and Polarized XAFS Results

Published online by Cambridge University Press:  01 January 2024

Jeffery A. Greathouse*
Affiliation:
Department of Chemistry, St. Lawrence University, Canton, NY 13617, USA
Hannah R. Stellalevinsohn
Affiliation:
Department of Chemistry, St. Lawrence University, Canton, NY 13617, USA
Melissa A. Denecke
Affiliation:
Forschungszentrum Karlsruhe GmbH, Institut für Nukleare Entsorgung, Postfach 3640, 76021 Karlsruhe, Germany
Andreas Bauer
Affiliation:
Forschungszentrum Karlsruhe GmbH, Institut für Nukleare Entsorgung, Postfach 3640, 76021 Karlsruhe, Germany
Roberto T. Pabalan
Affiliation:
Center for Nuclear Waste Regulatory Analyses, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238, USA
*
*E-mail address of corresponding author: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We report a combined experimental and theoretical study of uranyl complexes that form on the interlayer siloxane surfaces of montmorillonite. We also consider the effect of isomorphic substitution on surface complexation since our montmorillonite sample contains charge sites in both the octahedral and tetrahedral sheets. Results are given for the two-layer hydrate with a layer spacing of 14.58 Å. Polarized-dependent X-ray absorption fine structure spectra are nearly invariant with the incident angle, indicating that the uranyl ions are oriented neither perpendicular nor parallel to the basal plane of montmorillonite. The equilibrated geometry from Monte Carlo simulations suggests that uranyl ions form outer-sphere surface complexes with the [O=U=O]2+ axis tilted at an angle of ~45° to the surface normal.

Type
Research Article
Copyright
Copyright © The Clay Minerals Society 2005

References

Baeyens, B. and Bradbury, M.H., (1997) A mechanistic description of Ni and Zn sorption on Na-montmorillonite. 1. Titration and sorption measurements Journal of Contaminant Hydrology 27 199222 10.1016/S0169-7722(97)00008-9.Google Scholar
Bauer, A. and Berger, G., (1998) Kaolinite transformation in high molar KOH solutions Applied Geochemistry 13 905916 10.1016/S0883-2927(98)00018-3.Google Scholar
Chang, F-RC Skipper, N.T. and Sposito, G., (1995) Computer simulation of interlayer molecular structure in sodium montmorillonite hydrates Langmuir 11 27342741 10.1021/la00007a064.Google Scholar
Chavez-Paez, M. Van Workum, K. de Pablo, L. and de Pablo, J.J., (2001) Monte Carlo simulations of Wyoming sodium montmorillonite hydrates Journal of Chemical Physics 114 14051413 10.1063/1.1322639.CrossRefGoogle Scholar
Cygan, R.T. Liang, J.-J. and Kalinichev, A.G., (2004) Molecular models of hydroxide, oxyhydroxide, and clay phases and the development of a general force field Journal of Physical Chemistry B 108 12551266 10.1021/jp0363287.Google Scholar
Dähn, R. Scheidegger, A.M. Manceau, A. Curti, E. Baeyens, B. Bradbury, M.H. and Chateigner, D., (2002) Th uptake on montmorillonite: A powder and polarized extended X-ray absorption fine structure (EXAFS) study Journal of Colloid and Interface Science 249 821 10.1006/jcis.2002.8236.Google Scholar
Day, P.R. and Black, C.A., (1965) Particle fractionation and particle size analysis Methods of Soil Analysis Wisconsin American Society of Agronomy, Inc., Madison 545567.Google Scholar
Denecke, M.A. Dardenne, K. Lindqvist-Reis, P. and Rothe, J., (2003) Grazing incidence XAFS investigations of Hf(IV) and U(VI) cations sorbed onto mineral surfaces Physical Chemistry Chemical Physics 5 939946 10.1039/b211228k.Google Scholar
Dent, A.J. Ramsay, J.D.F. and Swanton, S.W., (1992) An EXAFS Study of uranyl ion in solution and sorbed onto silica and montmorillonite clay colloids Journal of Colloid and Interface Science 150 4560 10.1016/0021-9797(92)90267-P.Google Scholar
George, G.N. and Pickering, I.J., (1995) EXAFSPAK: A Suite of Computer Programs for Analysis of X-ray Absorption Spectra. USA Stanford Synchrotron Radiation Laboratory, Stanford, California.Google Scholar
Giaquinta, D.M. Soderholm, L. Yuchs, S.E. and Wasserman, S.R., (1997) The speciation of uranium in a smectite clay: evidence for catalysed uranyl reduction Radiochimica Acta 76 113121 10.1524/ract.1997.76.3.113.CrossRefGoogle Scholar
Grauer, R., (1994) Bentonite as a backfill material in a high-level waste repository MRS Bulletin 19 4346 10.1557/S0883769400048697.Google Scholar
Greathouse, J.A. and Sposito, G., (1998) Monte Carlo and molecular dynamic simulations of interlayer structure in Li(H20)3-smectites Journal of Physical Chemistry B 102 24062414 10.1021/jp980120h.Google Scholar
Greathouse, J.A. and Storm, E.W., (2002) Calcium hydration on montmorillonite clay surfaces studied by Monte Carlo simulation Molecular Simulation 28 633647 10.1080/0892702029003.Google Scholar
Greathouse, J.A. Refson, K. and Sposito, G., (2000) Molecular dynamics simulation of water mobility in magnesiumsmectite hydrates Journal of the American Chemical Society 122 1145911464 10.1021/ja0018769.Google Scholar
Hensen, E.J.M. and Smit, B., (2002) Why clays swell Journal of Physical Chemistry B 106 1266412667 10.1021/jp0264883.Google Scholar
Hudson, E.A. Allen, P.G. Terminello, L.J. Denecke, M.A. and Reich, T., (1996) Polarized x-ray absorption spectroscopy of the uranyl ion: comparison of experiment and theory Physical Review B 54 156165 10.1103/PhysRevB.54.156.Google Scholar
Karaborni, S. Smit, B. Heidug, W. Urai, J. and van Oort, E., (1996) The swelling of clays: molecular simulations of the hydration of montmorillonite Science 271 11021104 10.1126/science.271.5252.1102.Google Scholar
Lajudie, A. Raynal, J. Petit, J.-C. Toulhoat, P., Murakami, T. and Ewing, R.C., (1994) Clay-based materials for engineered barriers: A review Scientific Basis for Nuclear Waste Management XVIII USA Materials Research Society, Pittsburgh, Pennsylvania 221231.Google Scholar
Moore, D.M. Reynolds, R.C. Jr., (1989) X-ray Diffraction Oxford and New York Oxford University Press 322.Google ScholarPubMed
Neall, F.B. Baertschi, P. McKinley, L.G. Smith, P.A. Sumerling, T. Umeki, H., Murakami, T. and Ewing, R.C., (1994) Comparison of the concepts and assumptions in five recent HLW/spent fuel performance assessments Scientific Basis for Nuclear Waste Management XVIII USA Materials Research Society, Pittsburgh, Pennsylvania 503510.Google Scholar
Skipper, N.T., (1996) MONTE User’s Manual. UK Department of Physics and Astronomy, University College London.Google Scholar
Skipper, N.T. Soper, A.K. and McConnell, J.D.C., (1991) The structure of interlayer water in vermiculite Journal of Chemical Physics 94 57515760 10.1063/1.460457.Google Scholar
Skipper, N.T. Chang, F-RC and Sposito, G., (1995) Monte Carlo simulation of interlayer molecular structure in swelling clay minerals. 1. methodology Clays and Clay Minerals 43 285293 10.1346/CCMN.1995.0430303.CrossRefGoogle Scholar
Slade, P.G. Stone, P.A. and Radoslovich, E.W., (1985) Interlayer structures of the two-layer hydrates of Na- and Ca-vermiculites Clays and Clay Minerals 33 5161 10.1346/CCMN.1985.0330106.Google Scholar
Sylwester, E.R. Hudson, E.A. and Allen, P.G., (2000) The structure of uranium (VI) sorption complexes on silica, alumina, and montmorillonite Geochimica el Cosmochimica Acta 64 24312438 10.1016/S0016-7037(00)00376-8.Google Scholar
Tsunashima, A. Brindley, G.W. and Bastovanov, M., (1981) Adsorption of uranium from solutions by montmorillonite: compositions and properties of uranyl montmorillonites Clays and Clay Minerals 29 1016 10.1346/CCMN.1981.0290102.Google Scholar
Young, D.A. and Smith, D.E., (2000) Simulations of clay mineral swelling and hydration: dependence upon interlayer ion size and charge Journal of Physical Chemistry B 104 91639170 10.1021/jp000146k.CrossRefGoogle Scholar
Zabinsky, S.I. Rehr, J.J. Ankudinov, A. Albers, R.C. and Eller, M.J., (1995) Multiple-scattering calculations of x-ray-absorption spectra Physical Review B 52 29953009 10.1103/PhysRevB.52.2995.Google Scholar
Zaidan, O.F. Greathouse, J.A. and Pabalan, R.T., (2003) Monte Carlo and molecular dynamics simulation of uranyl adsorption on montmorillonite clay Clays and Clay Minerals 51 372381 10.1346/CCMN.2003.0510402.Google Scholar