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Bentonite pore distribution based on SAXS, chloride exclusion and NMR studies

Published online by Cambridge University Press:  09 July 2018

A. Muurinen*
Affiliation:
VTT Technical Research Centre of Finland. P.O. Box 1000, FI-02044 VTT, Finland
T. Carlsson
Affiliation:
VTT Technical Research Centre of Finland. P.O. Box 1000, FI-02044 VTT, Finland
A. Root
Affiliation:
MagSol, Tuhkanummenkuja 2, 00970 Helsinki, Finland
*
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Abstract

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Water-saturated bentonite is planned to be used in many countries as an important barrier component in high-level nuclear waste (HLW) repositories. Knowledge about the microstructure of the bentonite and the distribution of water between interlayer (IL) and non-interlayer (non-IL) pores is important for modelling of long-term processes. In this work the microstructure of water-saturated samples prepared from MX-80 bentonite was studied with nuclear magnetic resonance (NMR) and small-angle X-ray scattering spectroscopy (SAXS) coupled with chloride exclusion modelling. The sample dry densities ranged between 0.7 and 1.6 g/cm3. The NMR technique was used to get information about the relative amounts of different water types. Water in smaller volume domains has a shorter relaxation time than that in larger domains due to the average closer proximity of the water to the paramagnetic Fe at the layer surfaces. The results were obtained using 1H NMR T relaxation time measurements with the short inter-pulse CPMG method. The interpretation of the NMR results was made by fitting a sum of discrete exponentials to the observed decay curves. The SAXS measurement on bentonite samples was used to get information about the size distribution of the IL distance of montmorillonite. The chloride porosity measurements and Donnan exclusion calculations were used together with the SAXS results to evaluate the bentonite microstructure. In the model, the montmorillonite layers were organized in stacks having IL water between the layers and non-IL water between the stacks. In the modelling, the number of layers in the stacks was used as fitting parameters which determined the IL and non-IL surface areas. The fitting parameters were adjusted so that the modelled chloride concentration was equal to the measured one. The NMR studies and SAXS studies coupled with the Cl porosity measurements provided very similar pictures of how the porewater is divided in two phases in bentonite.

Type
Research Article
Creative Commons
Creative Common License - CCCreative Common License - BY
Copyright © The Mineralogical Society of Great Britain and Ireland 2013 This is an Open Access article, distributed under the terms of the Creative Commons Attribution license. (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

References

Birgersson, M. & Karnland, O. (2009) Ion equilibrium between montmorillonite interlayer space and the external solution. Geochimica et Cosmochimica Acta, 73, 1908–1923.10.1016/j.gca.2008.11.027Google Scholar
Bolt, G. & De Haan, F. (1982) Soil Chemistry B. Physico-Chemical Models. Elsevier, Amsterdam/New York.Google Scholar
Bolt, G. & Warketin, B. (1958) The negative adsorption of anions by clay suspensions. Kolloid Zeitschrift, 156, 41–46.10.1007/BF01812361CrossRefGoogle Scholar
Bradbury, M.H. & Baeyens, B. (2003) Porewater chemistry in compacted re-saturated MX-80 bentonite. Journal of Contaminant Hydrology, 61, 329–338.10.1016/S0169-7722(02)00125-0Google Scholar
Carlsson, T., Muurinen, A., Matusewicz, M. & Root, A. (2012) Porewater in compacted water-saturated MX-80 bentonite. Pp. 397–402 in: Materials Research Society Symposium Proceedings, 1475 (R.M. Carranza, G.S. Duffó & R.B. Rebak, editors). Materials Research Society, Warrendale, Pennsylvania.Google Scholar
Cebula, D.J., Thomas, R.K. & White, J.W. (1979) The structure and dynamics of clay-water systems studied by neutron scattering. Developments in Sedimentology, 27, 111–120.Google Scholar
Devineau, K., Bihannic, I., Michot, L., Villiéras, F., Masrouri, F., Cuisinier, O., Fragneto, G. & Michau, N. (2006) In situ neutron diffraction analysis of the influence of geometric confinement on crystalline swelling of montmorillonite. Applied Clay Science, 31, 76–84.10.1016/j.clay.2005.08.006Google Scholar
Edwards, D. & Quirk, J. (1962) Repulsion of chloride by montmorillonite. Journal of Colloid Science, 17, 872–882.10.1016/0095-8522(62)90066-1Google Scholar
Eriksen, T. & Jacobsson, A. (1984) Diffusion in clay. Experimental techniques and theoretical models. KBS Technical Report, 84–05, Swedish Nuclear Fuel Supply Co., Stockholm, Sweden.Google Scholar
Farrar, T.C. & Becker, E.D. (1971) Pulse and Fourier Transform NMR: Introduction to Theory and Methods. Academic Press, New York.Google Scholar
Fernández, A.M. & Rivas, P. (2005) Analysis and distribution of waters in the compacted FEBEX bentonite: pore water chemistry and adsorbed water. Pp. 257–275 in: Advances in Understanding Engineered Clay Barriers (Alonso, E.E. & Ledesma, A., editors). Taylor & Francis Group, London.Google Scholar
Ferrage, E., Tournassat, C., Rinnert, E. & Lanson, B. (2005) Influence of pH on the interlayer cationic composition and hydration state of Ca-montmorillonite: Analytical chemistry, chemical modelling and XRD profile modelling study. Geochimica et Cosmochimica Acta, 69, 2797–2812.10.1016/j.gca.2004.12.008Google Scholar
Holmboe, M. (2011) The Bentonite Barrier: Microstructural properties and the influence of gradiation. PhD thesis, Royal Institute of Technology, Stockholm.Google Scholar
Holmboe, M., Wold, S. & Jonsson, M. (2012). Porosity investigation of compacted bentonite using XRD profile modelling. Journal of Contaminant Hydrology 128, 19–32.Google Scholar
Karnland, O. (1998) Bentonite swelling pressure in strong NaCl solutions. POSIVA Report, 98–01, Posiva Oy, Helsinki.Google Scholar
Karnland, O., Muurinen, A. & Karlsson, F. (2005) Bentonite swelling pressure in NaCl solutions – Experimentally determined data and model calculations. Pp. 241–256 in: Advances in Understanding Engineered Clay Barriers (Alonso, E.E. & Ledesma, A., editors). Taylor & Francis Group, London.Google Scholar
Karnland, O., Olsson, S. & Nilsson, U. (2006) Mineralogy and sealing properties of various bentonites and smectite-rich clay materials. KBS Technical Report, 06–30, Swedish Nuclear Fuel and Waste Management Co., Stockholm.Google Scholar
Kaufhold, S., Dohrmann, R., & Klinkenberg, M. (2010) Water-uptake capacity of bentonites. Clays and Clay Minerals, 58, 37–43.10.1346/CCMN.2010.0580103Google Scholar
Kozaki, T., Inada, K., Sato, S. & Ohashi, H. (2001) Diffusion mechanisms of chloride in sodium montmorillonite. Journal of Contaminant Hydrology, 47, 159–170.10.1016/S0169-7722(00)00146-7CrossRefGoogle ScholarPubMed
Kumpulainen, S. & Kiviranta, L. (2010) Mineralogical and Chemical Characterization of Various Bentonite and Smectite-Rich Clay Materials. POSIVA Working Report, 2010–52, Posiva Oy, Olkiluoto.Google Scholar
Kumpulainen, S. & Kiviranta, L. (2011) Mineralogical, Chemical and Physical Study of Potential Buffer and Backfill Materials from ABM Test Package 1. POSIVA Working Report, 2011–41, Posiva Oy, Olkiluoto.Google Scholar
Moleira, M., Eriksen, T. & Jansson, M. (2003) Anion diffusion pathways in bentonite clay compacted to different dry densities. Applied Clay Science, 23, 69–76.Google Scholar
Montavon, G., Guo, Z., Tournassat, C., Grambow, B. & Le Botlan, D. (2009) Porosities accessible to HTO and iodide on water-saturated compacted clay materials and relation with the forms of water: A low field proton NMR study. Geochimica et Cosmochimica Acta, 73, 7290–7302.10.1016/j.gca.2009.09.014CrossRefGoogle Scholar
Morvan, M., Espinat, D., Lambard, J. & Zemb, Th. (1994) Ultrasmall- and small-angle X-ray scattering of smectite clay suspensions. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 82, 193–203.10.1016/0927-7757(93)02656-YGoogle Scholar
Muurinen, A. (1994) Diffusion of Anions and Cations in Compacted Sodium Bentonite. VTT Publications 168, Technical Research Centre of Finland Espoo.Google Scholar
Muurinen, A. (2009) Studies on the Chemical Conditions and Microstructure in the Reference Bentonites of Alternative Buffer Materials Project (ABM) in Äspö. POSIVA Working Report, 2009-42, Posiva Oy, Olkiluoto.Google Scholar
Muurinen, A. & Carlsson, T. (2010) Experiences of pH and Eh measurements in compacted MX-80 bentonite. Applied Clay Science, 47, 23–27.10.1016/j.clay.2008.05.007Google Scholar
Muurinen, A. & Carlsson, T. (2013) Bentonite pore structure based on SAXS, chloride exclusion and NMR studies. POSIVA Report (to be published).Google Scholar
Muurinen A, Karnland, O. & Lehikoinen, J. (2007) Effect of homogenization on the microstructure and exclusion of chloride in compacted bentonite. Physics and Chemistry of the Earth, Parts A/B/C, 32, 485–490.Google Scholar
Ohkubo, T., Kikuchi, H. & Yamaguchi, M. (2008) An approach of NMR relaxometry for understanding water in saturated compacted bentonite. Physics and Chemistry of the Earth, 33, S169–S176.Google Scholar
Overbeek, J. (1952) Electrochemistry of the double layer. Pp. 115–193 in: Colloid Science (Kruyt, H., editor). Elsevier Publishing Company, Amsterdam.Google Scholar
Pusch R. (1999) Microstructural evolution of buffers. Engineering Geology, 54, 33–41.Google Scholar
Pusch, R., Karnland, O. & Hökmark H. (1990) GMM – a general microstructural model for qualitative and quantitative studies on smectite clays. KBS Technical Report, 90–43, Swedish Nuclear Fuel and Waste Management Co., Stockholm.Google Scholar
Santyr, G.E., Henkelman, R.M. & Bronskill, M.J. (1988) Variation in measured transverse relaxation in tissue resulting from spin locking with the CPMG sequence. Journal of Magnetic Resonance, 79, 28–44.Google Scholar
Segad, M., Jönsson, B., Åkesson, T. & Cabane, B. (2010) Ca/Na montmorillonite: Structure, forces and swelling properties. Langmuir, 26, 5782–5790.10.1021/la9036293Google Scholar
Sposito, G. (1982) The diffuse-ion swarm near smectite particles suspended in 1:1 electrolyte solutions: modified Gouy-Chapman theory and quasicrystal formation. Pp. 127–156 in: Clay-Water Interface and its Rheological Implications (N. Güven & R.M. Pollastro, editors). Clay Minerals Society.CrossRefGoogle Scholar
Ståhlberg, J. (1999) Retention model for ions in chromatography. Journal of Chromatography A, 855, 3–55.10.1016/S0021-9673(99)00176-4Google Scholar
Suzuki, S., Sato, H., Ishidera, T. & 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, 23–37.10.1016/S0169-7722(03)00139-6Google Scholar
Tertre, E., Prêt, D & Ferrage, E. (2011a) Influence of the ionic strength and solid/solution ratio on Ca(II)-for- Na+ exchange on montmorillonite. Part 1: Chemical measurements, thermodynamic modelling and potential implications for trace elements geochemistry. Journal of Colloid and Interface Science, 353, 248–256.10.1016/j.jcis.2010.09.039Google Scholar
Tertre, E., Ferrage, E., Bihannic, I., Michot, L.J. & Prêt, D. (2011b) Influence of the ionic strength and solid/ solution ratio on Ca(II)-for-Na+ exchange on montmorillonite. Part 2: Understanding the effect of the m/V ratio. Implications for pore water composition and element transport in natural media. Journal of Colloid and Interface Science, 363, 334–347.10.1016/j.jcis.2011.07.003Google Scholar
Tournassat, C. & Appelo, C.A.J. (2011). Modelling approaches for anion-exclusion in compacted Nabentonite. Geochimica et Cosmochimica Acta, 75, 3698–3710.10.1016/j.gca.2011.04.001CrossRefGoogle Scholar
Van Loon, L.R., Glaus, M.A. & Müller, W. (2007) Anion exclusion effects in compacted bentonites: towards a better understanding of anion diffusion. Applied Geochemistry, 22, 2536–2552.10.1016/j.apgeochem.2007.07.008Google Scholar
van Olphen, H. (1977) An Introduction to Clay Colloid Chemistry. John Wiley & Sons, New York.Google Scholar
Warr, L. & Berger, J. (2007) Hydration of bentonite in natural waters: Application of “confined volume” wet-cell X-ray diffractometry. Physics and Chemistry of the Earth, 32, 247–258.Google Scholar
Wersin, P. (2003) Geochemical modelling of bentonite porewater in high-level waste repositories. Journal of Contaminant Hydrology, 61, 405–422.10.1016/S0169-7722(02)00119-5CrossRefGoogle ScholarPubMed