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Colloid Diffusion in Compacted Bentonite: Microstructural Constraints

Published online by Cambridge University Press:  01 January 2024

Michael Holmboe*
Affiliation:
KTH School of Chemical Science and Engineering, Nuclear Chemistry, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
Susanna Wold
Affiliation:
KTH School of Chemical Science and Engineering, Nuclear Chemistry, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
Mats Jonsson
Affiliation:
KTH School of Chemical Science and Engineering, Nuclear Chemistry, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
*
* E-mail address of corresponding author: holmboe@kth.se

Abstract

In Sweden and in many other countries, a bentonite barrier will be used in the repository for spent nuclear fuel. In the event of canister failure, colloidal diffusion is a potential, but scarcely studied mechanism of radionuclide migration through the bentonite barrier. Column and in situ experiments are vital in understanding colloid diffusion and in providing information about the micro structure of compacted bentonite and identifying cut-off limits for colloid filtration. This study examined diffusion of negatively charged 2-, 5-, and 15-nm gold colloids in 4-month diffusion experiments using MX-80 Wyoming bentonite compacted to dry densities of 0.6–2.0 g/cm3. Breakthrough of gold colloids was not observed in any of the three diffusion experiments. In a gold-concentration profile analysis, colloid diffusion was only observed for the smallest gold colloids at the lowest dry density used (estimated apparent diffusivity Da ≈ 5 × 10−13 m2/s). The results from a microstructure investigation using low-angle X-ray diffraction suggest that at the lowest dry density used, interlayer transport of the smallest colloids cannot be ruled out as a potential diffusion pathway, in addition to the expected interparticle transport. In all other cases, with either greater dry densities or larger gold colloids, compacted bentonite will effectively prevent diffusion of negatively charged colloids due to filtration.

Type
Article
Copyright
Copyright © The Clay Minerals Society 2010

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References

Bourg, I.C. Bourg, A.C.M. and Sposito, G., 2003 Modeling diffusion and adsorption in compacted bentonite: a critical review Journal of Contaminant Hydrology 61 293302 10.1016/S0169-7722(02)00128-6.CrossRefGoogle ScholarPubMed
Devineau, K. Bihannic, I. Michot, L. Villiéras, F. Masrouri, F. Cuisinier, O. Fragneto, G. and Michau, N., 2006 In situ neutron diffraction analysis of the influence of geometric confinement on crystalline swelling of montmorillonite Applied Clay Science 31 7684 10.1016/j.clay.2005.08.006.CrossRefGoogle Scholar
Enu¨stu¨n, B.V. and Turkevich, J., 1963 Coagulation of colloidal gold Journal of the American Chemical Society 85 33173328 10.1021/ja00904a001.CrossRefGoogle Scholar
Eriksen, T. Jansson, M., 1996 Diffusion of I, Cs+ and Sr + in compacted bentonite — Anion exclusion and surface diffusion SKB Technical Report Stockholm, Sweden Swedish Nuclear Fuel and Waste Management Co..Google Scholar
Ferrage, E. Lanson, B. Sakharov, B.A. and Drits, V.A., 2005 Investigation of smectite hydration properties by modeling experimental X-ray diffraction patterns: Part I. Montmorillonite hydration properties American Mineralogist 90 13581374 10.2138/am.2005.1776.CrossRefGoogle Scholar
Gregg, S.J. and Sing, K.S.W., 1982 Adsorption, Surface Area and Porosity 2n London Academic Press.Google Scholar
Iijima, K., Kurosawa, S., Tobita, M., Kibe, S., and Ouchi, Y. (2009) Diffusion behavior of humic acid in compacted bentonite: effect of ionic strength, dry density and molecular weight of humic acid. Material Research Society Symposium Proceedings. Scientific Basis for Nuclear Waste Management XXXII, 1124-Q05-04.Google Scholar
Janeba, D. Capkova, P. Weiss, Z. and Schenk, H., 1988 Characterization of intercalated smectites using XRD profile analysis in the low-angle region Clays and Clay Minerals 46 6368 10.1346/CCMN.1998.0460107.CrossRefGoogle Scholar
Kang, S. and Xing, B., 2007 Adsorption of dicarboxylic acids by clay minerals as examined by in situ ATR-FTIR and ex situ DRIFT Langmuir 23 70247031 10.1021/la700543f.CrossRefGoogle ScholarPubMed
Karnland, O. Olsson, S. Nilsson, U. and Sellin, P., 2006 Mineralogy and sealing properties of various bentonites and smectite rich materials SKB Technical Report .Google Scholar
Kozaki, T. Fujishima, A. and Sato, S., 1998 Self-diffusion of sodium ions in compacted montmorillonite Nuclear Technology 121 6369 10.13182/NT98-A2819.CrossRefGoogle Scholar
Kurosawa, S. and Ueta, S., 2001 Effect of colloids on radionuclide migration for performance assessment of HLW disposal in Japan Pure and Applied Chemistry 73 20272037 10.1351/pac200173122027.CrossRefGoogle Scholar
Luckham, P.F. and Rossi, S., 1999 The colloidal and rheological properties of bentonite suspensions Advances in Colloid and Interface Science 82 4392 10.1016/S0001-8686(99)00005-6.CrossRefGoogle Scholar
Molera, M. Eriksen, T. and Jansson, M., 2003 Anion diffusion pathways in bentonite clay compacted to different dry densities Applied Clay Science 23 6976 10.1016/S0169-1317(03)00088-7.CrossRefGoogle Scholar
Moore, D.M. and Reynolds, RC Jr., 1997 X-ray Diffraction and the Identification and Analysis of Clay Minerals 2nd New York Oxford University Press.Google Scholar
Muurinen, A., 2009 Studies on the chemical conditions and microstructure in the reference bentonites of alternative buffer materials project (ABM) in Aspöit .Google Scholar
Muurinen, A. Karnland, O. and Lehikoinen, J., 2004 Ion concentration caused by an external solution into the porewater of compacted bentonite Physics and Chemistry of the Earth 29 119127 10.1016/j.pce.2003.11.004.CrossRefGoogle Scholar
Norrish, K., 1954 The swelling of montmorillonite Discussions of the Faraday Society 18 120134 10.1039/df9541800120.CrossRefGoogle Scholar
Norrish, K. and Rausell-Colom, J.A., 1962 Effect of Freezing on the swelling of clay minerals Clay Minerals Bulletin 5 916 10.1180/claymin.1962.5.27.02.CrossRefGoogle Scholar
Nowak, E.J., 1984 Diffusion of colloids and other waste species in brine-saturated backfill materials Materials Research Society Symposium Proceedings, Scientific Basis for Nuclear Waste Management 26 5968 10.1557/PROC-26-59.Google Scholar
Saiyouri, N. Tessier, D. and Hicher, P.Y., 2004 Experimental study of swelling in unsaturated compacted clays Clay Minerals 39 469479 10.1180/0009855043940148.CrossRefGoogle Scholar
Secor, R.B. and Radke, C.J., 1985 Spillover of the diffuse double layer on montmorillonite particles Journal of colloid and Interface Science 103 237244 10.1016/0021-9797(85)90096-7.CrossRefGoogle Scholar
Segad, M. Jönsson, B. Akesson, T. and Cabane, B., 2010 Ca/Na-montmorillonite: structure, forces and swelling properties Langmuir 26 57825790 10.1021/la9036293.CrossRefGoogle ScholarPubMed
Suzuki, S. Sato, H. Ishidera, T. and Fujii, N., 2004 Study on anisotropy of effective diffusion coefficient and activation energy for deuterated water in compacted sodium bentonite Journal of Contaminant Hydrology 68 2337 10.1016/S0169-7722(03)00139-6.CrossRefGoogle Scholar
Tombácz, E. and Szekeres, M., 2004 Colloidal behavior of aqueous montmorillonite suspensions: the specific role of pH in the presence of indifferent electrolytes Applied Clay Science 27 7594 10.1016/j.clay.2004.01.001.CrossRefGoogle Scholar
Vaia, R.A. and Liu, W., 2002 X-ray powder diffraction of polymer/layered silicate nanocomposites: model and practice Journal of Polymer Science: Part B: Polymer Physics 40 15901600 10.1002/polb.10214.CrossRefGoogle Scholar
Vilks, P. Stroes-Gascoyne, S. Goulard, M. Haveman, S.A. and Bachinski, D.B., 1998 The release of organic material from clay-based buffer materials and its potential implications for radionuclide transport Radiochimica Acta 82 385391 10.1524/ract.1998.82.special-issue.385.CrossRefGoogle Scholar
Wold, S. and Eriksen, T., 2007 Diffusion of humic colloids in compacted bentonite Physics and Chemistry of the Earth 32 477484 10.1016/j.pce.2006.05.002.CrossRefGoogle Scholar
Zhang, Z.Z. and Low, P.F., 1989 Relation between the heat of immersion and the initial water content of Li-, Na-, and K-montmorillonite Journal of Colloid and Interface Science 133 461472 10.1016/S0021-9797(89)80057-8.CrossRefGoogle Scholar
Zhu, T V K Kreiter, M. Mittler, S. and Knoll, W., 2003 Surface modification of citrate-reduced colloidal gold nanoparticles with 2-mercaptosuccinic acid Langmuir 19 95189525 10.1021/la035157u.CrossRefGoogle Scholar