Hostname: page-component-7479d7b7d-767nl Total loading time: 0 Render date: 2024-07-11T17:10:31.388Z Has data issue: false hasContentIssue false

Monte Carlo and Molecular Dynamics Simulation of Uranyl Adsorption on Montmorillonite Clay

Published online by Cambridge University Press:  01 January 2024

Omar F. Zaidan
Affiliation:
Department of Chemistry, St. Lawrence University, Canton, NY 13617, USA
Jeffery A. Greathouse*
Affiliation:
Department of Chemistry, St. Lawrence University, Canton, NY 13617, USA
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: jgreathouse@stlawu.edu

Abstract

We performed Monte Carlo and molecular dynamics simulations to investigate the interlayer structure of a uranyl-substituted smectite clay. Our clay model is a dioctahedral montmorillonite with negative charge sites in the octahedral sheet only. We simulated a wide range of interlayer water content (0 mg H2O/g clay — 260 mg H2O/g clay), but we were particularly interested in the two-layer hydrate that has been the focus of recent X-ray absorption experiments. Our simulation results for the two-layer hydrate of uranyl-montmorillonite yield a water content of 160 mg H2O/g clay and a layer spacing of 14.66 Å. Except at extremely low water content, uranyl cations are oriented nearly parallel to the surface normal in an outer-sphere complex. The first coordination shell consists of five water molecules with an average U-O distance of 2.45 Å, in good agreement with experimental data. At low water content, the cations can assume a perpendicular orientation to include surface oxygen atoms in the first coordination shell. Our molecular dynamics results show that UO2(H2O)52+ complexes translate within the clay pore through a jump diffusion process, and that first-shell water molecules are exchangeable and interchangeable.

Type
Research Article
Copyright
Copyright © 2003, The Clay Minerals Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Allen, M.P. and Tildesley, D.J., (1987) Computer Simulation of Liquids Oxford, UK Clarendon Press 385 pp.Google Scholar
Axe, L. Anderson, P.R. and Jenne, E.A., (1998) Intraparticle diffusion of metal contaminants in amorphous oxide minerals Adsorption of Metals by Geomedia San Diego, USA Academic Press 193208 10.1016/B978-012384245-9/50009-8.CrossRefGoogle Scholar
Berendsen, H.J.C. Grigera, J.R. and Straatsma, T.P., (1987) The missing term in effective pair potentials Journal of Physical Chemistry 91 62696271 10.1021/j100308a038.Google Scholar
Boek, E.S. Coveney, P.V. and Skipper, N.T., (1995) Monte Carlo molecular modeling studies of hydrated Li-, Na-, and K-smectites: Understanding the role of potassium as a clay swelling inhibitor Journal of the American Chemical Society 117 1260812617 10.1021/ja00155a025.Google Scholar
Breen, C. Madejová, J. and Komadel, P., (1995) Characterisation of moderately acid-treated, size-fractionated montmorillonites using IR and MAS NMR spectroscopy and thermal analysis Journal of Materials Chemistry 5 469474 10.1039/JM9950500469.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
Chang, F-RC Skipper, N.T. and Sposito, G., (1997) Monte Carlo and molecular dynamics simulations of interfacial structure in lithium-montmorillonite hydrates Langmuir 13 20742082 10.1021/la9603176.Google Scholar
Chang, F-RC Skipper, N.T. and Sposito, G., (1998) Monte Carlo and molecular dynamics simulations of electrical double-layer structure in potassium-montmorillonite hydrates Langmuir 14 12011207 10.1021/la9704720.Google Scholar
Chavez-Paez, M. dePablo, L. and dePablo, J.J., (2001) Monte Carlo simulations of Ca-montmorillonite hydrates Journal of Chemical Physics 114 1094810953 10.1063/1.1374536.Google Scholar
Chisholm-Brause, C.J. Berg, J.M. Matzner, R.A. and Morris, D.E., (2001) Uranium (VI) sorption complexes on montmor-illonite as a function of solution chemistry Journal of Colloid and Interface Science 233 3849 10.1006/jcis.2000.7227.Google Scholar
Denecke, M.A. Bauer, A. Kim, J.I. Moll, H., Schussler, W. and Bauer, A., (1999) Polarization dependent XANES of uranium(VI) sorbed onto smectite Mineral/Water Interactions Close to Equilibrium Karlsruhe, Germany Forschungszentrum Karlsruhe GmbH 3537 Workshop, Speyer, March 25–26, 1999.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
Floris, F.M. Perisco, M. Tani, A. and Tomasi, J., (1994) Hydration shell structure of the calcium ion from simulations with ab initio effective pair potentials Chemical Physics Letters 227 126132 10.1016/0009-2614(94)00800-0.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.Google 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 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 magnesium-smectite hydrates Journal of the American Chemical Society 122 1145911464 10.1021/ja0018769.Google Scholar
Greathouse, J.A. O’Brien, R.J. Bemis, G. and Pabalan, R.T., (2002) Molecular dynamics study of aqueous uranyl interactions with quartz (010) Journal of Physical Chemistry B 106 16461655 10.1021/jp013250q.Google Scholar
Guilbaud, P. and Wipff, G., (1996) Force field representation of the UO2 2+ cation from free energy MD simulations in water. Tests on its 18-crown-6 and NO3 adducts, and on its calix[6]arene6− and CMPO complexes Journal of Molecular Structure (THEOCHEM) 366 5563 10.1016/0166-1280(96)04496-X.Google Scholar
Hartzell, C.J. Cygan, R.T. and Nagy, K.L., (1998) Molecular modeling of the tributyl phosphate complex of europium ni trate in the clay hectorite Journal of Physical Chemistry A 102 67226729 10.1021/jp981089m.Google Scholar
Hyun, S.P. Cho, Y.H. Hahn, P.S. and Kim, S.J., (2001) Sorption mechanism of U(VI) on a reference montmorillonite: binding to the internal and external surfaces Journal of Radioanalytical and Nuclear Chemistry 250 5562 10.1023/A:1013212130177.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 Pittsburgh, Pennsylvania, USA Materials Research Society 221 231.Google Scholar
McKinley, J.P. Zachara, J.M. Smith, S.C. and Turner, G.D., (1995) The influence of uranyl hydrolysis and multiple site-binding reactions on adsorption of U(VI) to montmorillonite Clays and Clay Minerals 45 586598 10.1346/CCMN.1995.0430508.Google Scholar
National Research Council, Research needs in Subsurface Science (2000) Washington, D.C National Academy Press.Google Scholar
Neall, F.B. Baertschi, P. McKinley, I.G. Smith, P.A. Sumerling, T. Umeki, H., Murakami, T. and Ewing, R.C., (1995) Comparison of the concepts and assumptions in five recent HLW/spent fuel performance assessments Scientific Basis for Nuclear Waste Management XVIII Pittsburgh, Pennsylvania, USA Materials Research Society 503 510.Google Scholar
Pabalan, R.T. and Turner, D.R., (1997) Uranium (6+) sorption on montmorillonite: experimental and surface complexation modeling study Aquatic Geochemistry 2 203226 10.1007/BF00119855.Google Scholar
Pabalan, R.T. Turner, D.R. Bertetti, F.P. Prikryl, J.D. and Jenne, E., (1998) Uranium(VI) sorption onto selected mineral surfaces Adsorption of Metals by Geomedia San Diego, California Academic Press 99130 10.1016/B978-012384245-9/50004-9.Google Scholar
Poinsignon, C. Estrade-Szwarckopf, J. Conard, J. Dianoux, A.J., Schultz, L.G. van Olphen, H. and Mumpton, F.A., (1987) Water dynamics in the clay-water system: A quasi-elastic neutron scattering study Proceedings of the International Clay Conference Denver Bloomington, Indiana Clay Minerals Society 284 291.Google Scholar
Reeder, R.J. Nugent, M. Pabalan, R.T. and Cidu, R., (2001) Local structure of uranium (VI) sorbed on clinoptilolite and montmorillonite Water-Rock Interaction Lisse, The Netherlands A.A. Balkema 423 426.Google Scholar
Refson, K., (2000) Moldy: a portable molecular dynamics simulation program for serial and parallel computers Computer Physics Communications 126 310329 10.1016/S0010-4655(99)00496-8.Google Scholar
Riley, R.G. Zachara, J.M. and Wobber, F.J., (1992) Chemical Contaminants on DOE Lands and Selection of Contaminant Mixtures for Subsurface Science Research Washington, D.C. US Department of Energy, Office of Energy Research.Google Scholar
Skipper, N.T., (1996) MONTE User’s Manual London Department of Physics and Astronomy, University College.Google Scholar
Skipper, N.T. Refson, K. and McConnell, J.D.C., (1991) Computer simulation of interlayer water in 2:1 clays Journal of Chemical Physics 94 74347445 10.1063/1.460175.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.Google Scholar
Smith, D.E., (1998) Molecular computer simulations of the swelling properties and interlayer structure of cesium montmorillonite Langmuir 14 59595967 10.1021/la980015z.CrossRefGoogle Scholar
Sylwester, E.R. Hudson, E.A. and Allen, P.G., (2000) The structure of uranium (VI) sorption complexes on silica, a lumina, a nd montmorillonite Geochimica et Cosmochimica Acta 64 24312438 10.1016/S0016-7037(00)00376-8.Google Scholar
Teppen, B.J. Rasmussen, K.R. Bertsch, P.M. Miller, D.M. and Schafer, L., (1997) Molecular dynamics modeling of clay minerals. 1. Gibbsite, kaolinite, pyrophillite, and beidellite Journal of Physical Chemistry B 101 15791587 10.1021/jp961577z.Google Scholar
Teppen, B.J. Yu, C.-H. Miller, D.M. and Schafer, L., (1998) Molecular dynamics simulations of sorption of organic compounds at the clay mineral/aqueous solution interface Journal of Computational Chemistry 19 144153 10.1002/(SICI)1096-987X(19980130)19:2<144::AID-JCC7>3.0.CO;2-U.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.Google Scholar
Zachara, J.M. and McKinley, J.P., (1993) Influence of hydrolysis on the sorption of metal cations by smectites: Importance of edge coordination reactions Aquatic Science 55 251261 10.1007/BF00877270.Google Scholar