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Ion-Exchange Modeling of Divalent Cation Adsorption on SWy-3 Montmorillonite

Published online by Cambridge University Press:  01 January 2024

Yayu W. Li*
Affiliation:
Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT 06269-4067, USA
Cristian P. Schulthess
Affiliation:
Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT 06269-4067, USA
*
*E-mail address of corresponding author: yayu.li@uconn.edu

Abstract

Ion-exchange modeling is used widely to describe and predict ion-adsorption data on clay minerals. Although the model parameters are usually optimized by curve fitting experimental data, this approach does not confirm the identity of the adsorption sites. The purpose of the present study was to extend to divalent cations a previous study on the retention of monovalent cations on Na-saturated montmorillonite (NaMnt) which optimized some of the model parameters using density functional theory (DFT) simulations. The adsorption strength of divalent cations increased in the order Mg2+ < Cd2+ < Ca2+ < Sr2+ < Ba2+. After adding adsorption of metal hydroxide species (MOH+), the three-site ion-exchange model was able to describe adsorption data over a wide pH range (pH 1–10) on NaMnt. X-ray diffraction (XRD) analyses were conducted to investigate the interlayer dimension of clay samples under various conditions. The cation retention strengths of divalent cations did not correlate with interlayer dimensions. The XRD analyses of the Mnt showed a d001 value of 19.6 Å when saturated with alkaline earth cations, 22.1 Å with Cd2+, 15.6 Å with Na+, and 15.2 Å with H+. In the case of Na+, the 15.6 Å peak decreased gradually and disappeared, and new peaks at 22.1 and 19.6 Å appeared when the percentages of Mg2+ and Ba2+ adsorbed increased on NaMnt. The peak shifted from 22.1 to 20.3 and 19.6 Å when the pH increased for all cations except Cd2+, which stayed constant at 22.1 Å. The coexistence of multiple d001 peaks in the XRD patterns suggested that the interlayer cations were segregated, and that the interlayer ion–ion interactions among different types of ions were minimized.

Type
Article
Copyright
Copyright © Clay Minerals Society 2021

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References

Bala, P., Samantaray, B. K., & Srivastava, S. K. (2000). Dehydration transformation in Ca-montmorillonite. Bulletin of Materials Science, 23, 6167.CrossRefGoogle Scholar
Baeyens, B., & Bradbury, M. H. (1997). A mechanistic description of Ni and Zn sorption on Na-montmorillonite Part I: Titration and sorption measurements. Journal of Contaminant Hydrology, 27, 199222.CrossRefGoogle Scholar
Baeyens, B., & Bradbury, M. H. (2004). Cation exchange capacity measurements on illite using the sodium and cesium isotope dilution technique: Effects of the index cation, electrolyte concentration and competition: Modeling. Clays and Clay Minerals, 52, 421431.CrossRefGoogle Scholar
Barbier, F., Duc, G., & Petit-Ramel, M. (2000). Adsorption of lead and cadmium ions from aqueous solution to the montmorillonite/water interface. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 166, 153159.CrossRefGoogle Scholar
Benson, L.V. (1980). Tabulation and evaluation of ion exchange data on smectites, certain zeolites and basalt (No. LBL-10541). California Univ., Berkeley (USA). Lawrence Berkeley Lab.CrossRefGoogle Scholar
Berghout, A., Tunega, D., & Zaoui, A. (2010). Density functional theory (DFT) study of the hydration steps of Na+/ Mg2+/Ca2+/Sr2+/Ba2+-exchanged montmorillonites. Clays and Clay Minerals, 58, 174187.CrossRefGoogle Scholar
Bhattacharyya, K. G., & Gupta, S. S. (2008). Influence of acid activation on adsorption of Ni (II) and Cu (II) on kaolinite and montmorillonite: kinetic and thermodynamic study. Chemical Engineering Journal, 136, 113.CrossRefGoogle Scholar
Bradbury, M. H., & Baeyens, B. (2005). Experimental measurements and modeling of sorption competition on montmorillonite. Geochimica et Cosmochimica Acta, 69, 41874197.CrossRefGoogle Scholar
Charlet, L., & Tournassat, C. (2005). Fe (II)-Na (I)-Ca (II) cation exchange on montmorillonite in chloride medium: Evidence for preferential clay adsorption of chloride-metal ion pairs in seawater. Aquatic Geochemistry, 11, 115137.CrossRefGoogle Scholar
Chen, T., Yuan, Y., Zhao, Y., Rao, F., & Song, S. (2019). Preparation of montmorillonite nanosheets through freezing/thawing and ultrasonic exfoliation. Langmuir, 35, 23682374.CrossRefGoogle ScholarPubMed
Chiou, C. T., & Rutherford, D. W. (1997). Effects of exchanged cation and layer charge on the sorption of water and EGME vapors on montmorillonite clays. Clays and Clay Minerals, 45, 867880.CrossRefGoogle Scholar
Cullen, J. T. & Maldonado, M. T. (2013). Biogeochemistry of cadmium and its release to the environment. Pp. 3162 in: Cadmium: From Toxicity to Essentiality (Sigel, A., Sigel, H., and Sigel, R. K.O., editors). Springer, Dordrecht, Netherlands.CrossRefGoogle Scholar
Davies, C. W. (1938). The extent of dissociation of salts in water. Part VIII. An equation for the mean ionic activity coefficient of an electrolyte in water, and a revision of the dissociation constants of some sulphates. Journal of the Chemical Society, Part II, 20932098.Google Scholar
Dazas, B., Ferrage, E., Delville, A., & Lanson, B. (2014). Interlayer structure model of tri-hydrated low-charge smectite by X-ray diffraction and Monte Carlo modeling in the Grand Canonical ensemble. American Mineralogist, 99, 17241735.CrossRefGoogle Scholar
Di Leo, P., & Cuadros, J. (2003). 113Cd, 1H MAS NMR and FTIR analysis of Cd2+ adsorption on dioctahedral and trioctahedral smectite. Clays and Clay Minerals, 51, 403414.CrossRefGoogle Scholar
Dzene, L., Ferrage, E., Hubert, F., Delville, A., & Tertre, E. (2016). Experimental evidence of the contrasting reactivity of external vs. interlayer adsorption sites on swelling clay minerals: The case of Sr2+-for-Ca2+ exchange in vermiculite. Applied Clay Science, 132, 205215.CrossRefGoogle Scholar
Efron, B. (1978). Regression and ANOVA with zero-one data: Measures of residual variation. Journal of the American Statistical Association, 73, 113121.CrossRefGoogle Scholar
Farrah, H., Hatton, D., & Pickering, W. F. (1980). The affinity of metal ions for clay surfaces. Chemical Geology, 28, 5568.CrossRefGoogle Scholar
Fehervari, A., Gates, W. P., Bouazza, A., & Shackelford, C. D. (2019). Assessment of bentonite compatibility with salinity using centrifugation-based water retention. Geotechnical Testing Journal, 42, 275295.CrossRefGoogle Scholar
Fernandes, M. M., & Baeyens, B. (2019). Cation exchange and surface complexation of lead on montmorillonite and illite including competitive adsorption effects. Applied Geochemistry, 100, 190202.CrossRefGoogle Scholar
Ferrage, E., Lanson, B., Sakharov, B. A., & Drits, V. A. (2005a). Investigation of smectite hydration properties by modeling experimental X-ray diffraction patterns: Part I. Montmorillonite hydration properties. American Mineralogist, 90, 13581374.CrossRefGoogle Scholar
Ferrage, E., Tournassat, C., Rinnert, E., Charlet, L., & Lanson, B. (2005b). Experimental evidence for Ca-chloride ion pairs in the interlayer of montmorillonite. An XRD profile modeling approach. Clays and Clay Minerals, 53, 348360.CrossRefGoogle Scholar
Ferrage, E., Tournassat, C., Rinnert, E., & Lanson, B. (2005c). 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, 27972812.CrossRefGoogle Scholar
Fleischer, M. (1953). Recent estimates of the abundances of the elements in the earth's crust (No. 285). United States Department of the Interior, Geological Survey, Washington, D. C.Google Scholar
Fripiat, J. J., & Van Damme, H. (1983). Surface Mobility in Chemical Reactions and Catalysis. Surface Mobilities on Solid Materials, Fundamental concepts and applications. NATO ASI Series B: Physics, 86, 493526. Springer, Boston, MA, USA.CrossRefGoogle Scholar
Glaeser, R., & Méring, J. (1954). lsothermes d'hydratation des montmorillonites bi-ioniques (Na, Ca). Clay Minerals Bulletin, 2, 188193.CrossRefGoogle Scholar
Gu, X., Evans, L. J., & Barabash, S. J. (2010). Modeling the adsorption of Cd (II), Cu (II), Ni (II), Pb (II) and Zn (II) onto montmorillonite. Geochimica et Cosmochimica Acta, 74, 57185728.CrossRefGoogle Scholar
Holmboe, M., Wold, S., & Jonsson, M. (2012). Porosity investigation of compacted bentonite using XRD profile modeling. Journal of Contaminant Hydrology, 128, 1932.CrossRefGoogle ScholarPubMed
Iwasaki, T., & Watanabe, T. (1988). Distribution of Ca and Na ions in dioctahedral smectites and interstratified dioctahedral mica/smectites. Clays and Clay Minerals, 36, 7382.CrossRefGoogle Scholar
Jacquier, P., Ly, J., & Beaucaire, C. (2004). The ion-exchange properties of the Tournemire argillite: I. Study of the H, Na, K, Cs, Ca and Mg behaviour. Applied Clay Science, 26, 163170.CrossRefGoogle Scholar
Jones, J. B. Jr. (2012). Plant Nutrition and Soil Fertility Manual. . CRC Press, Boca Raton, Florida, USACrossRefGoogle Scholar
Kaufhold, S., & Dohrmann, R. (2008). Detachment of colloidal particles from bentonites in water. Applied Clay Science, 39, 5059.CrossRefGoogle Scholar
Kaufhold, S., Dohrmann, R., Stucki, J. W., & Anastácio, A. S. (2011). Layer charge density of smectites–closing the gap between the structural formula method and the alkyl ammonium method. Clays and Clay Minerals, 59, 200211.CrossRefGoogle Scholar
Klika, Z., Kraus, L., & Vopálka, D. (2007). Cesium uptake from aqueous solutions by bentonite: A comparison of multicomponent sorption with ion-exchange models. Langmuir, 23, 12271233.CrossRefGoogle ScholarPubMed
Kravchenko, J., Darrah, T. H., Miller, R. K., Lyerly, H. K., & Vengosh, A. (2014). A review of the health impacts of barium from natural and anthropogenic exposure. Environmental Geochemistry and Health, 36, 797814.CrossRefGoogle ScholarPubMed
Lagoutine, F., Legrand, J., & Bac, C. (1978). Half-lives of some radionuclides. International Journal of Applied Radiation and Isotopes, 29, 269272.CrossRefGoogle Scholar
Laird, D. A. (2006). Influence of layer charge on swelling of smectites. Applied Clay Science, 34, 7487.CrossRefGoogle Scholar
Laudelout, H., Van Bladel, R., Bolt, G. H., & Page, A. L. (1968). Thermodynamics of heterovalent cation exchange reactions in a montmorillonite clay. Transactions of the Faraday Society, 64, 14771488.CrossRefGoogle Scholar
Levy, R., & Francis, C. W. (1975). A quantitative method for the determination of montmorillonite in soils. Clays and Clay Minerals, 23, 8589.CrossRefGoogle Scholar
Li, W. Y. & Schulthess, C. P. (2020). Ion-exchange modeling of monovalent alkali cation adsorption on Montmorillonite. Clays and Clay Minerals, 68, 476490CrossRefGoogle Scholar
Li, W. Y., Schulthess, C. P., Co, K., Sahoo, S., & Alpay, S. P. (2020). Influence of octahedral cation distribution in montmorillonite on interlayer hydrogen counter-ion retention strength by DFT simulation. Clays and Clay Minerals, 110.Google Scholar
Libby, W. F. (1956). Radioactive fallout and radioactive strontium. Science, 123, 657660.CrossRefGoogle ScholarPubMed
Mamy, J., & Gaultier, J. P. (1979). Etude comparee de l'evolution des montmorillonites biioniques K-Ca de Camp-Berteaux et du Wyoming sous l'effet des cycles d'humectation et de dessiccation. Clay Minerals, 14, 181192.CrossRefGoogle Scholar
Martin, L. A., Wissocq, A., Benedetti, M. F., & Latrille, C. (2018). Thallium (Tl) sorption onto illite and smectite: Implications for Tl mobility in the environment. Geochimica et Cosmochimica Acta, 230, 116.CrossRefGoogle Scholar
Milodowski, A. E., Norris, S., & Alexander, W. R. (2016). Minimal alteration of montmorillonite following long-term interaction with natural alkaline groundwater: Implications for geological disposal of radioactive waste. Applied Geochemistry, 66, 184197.CrossRefGoogle Scholar
Missana, T., Benedicto, A., García-Gutiérrez, M., & Alonso, U. (2014). Modeling cesium retention onto Na-, K-and Ca-smectite: Effects of ionic strength, exchange and competing cations on the determination of selectivity coefficients. Geochimica et Cosmochimica Acta, 128, 266277.CrossRefGoogle Scholar
Missana, T., & García-Gutiérrez, M. (2007). Adsorption of bivalent ions (Ca (II), Sr (II) and Co (II)) onto FEBEX bentonite. Physics and Chemistry of the Earth, Parts A/B/C, 32, 559567.CrossRefGoogle Scholar
Molera, M., Eriksen, T. & Wold, S. (2002). Modeling strontium sorption in natural and purified bentonite clay. TRePro workshop of the Forschungszentrum Karlsruhe, March 2002: Modelling of Coupled Transport Reaction Processes. 6064.Google Scholar
Montemore, M. M., van Spronsen, M. A., Madix, R. J., & Friend, C. M. (2017). O2 activation by metal surfaces: Implications for bonding and reactivity on heterogeneous catalysts. Chemical Reviews, 118, 28162862.CrossRefGoogle ScholarPubMed
Morodome, S., & Kawamura, K. (2011). In situ X-ray diffraction study of the swelling of montmorillonite as affected by exchangeable cations and temperature. Clays and Clay Minerals, 59, 165175.CrossRefGoogle Scholar
Motellier, S., Ly, J., Gorgeon, L., Charles, Y., Hainos, D., Meier, P., & Page, J. (2003). Modelling of the ionexchange properties and indirect determination of the interstitial water composition of an argillaceous rock. Application to the Callovo-Oxfordian low-water-content formation. Applied Geochemistry, 18, 15171530.CrossRefGoogle Scholar
Nash, V. E. & Marshall, C. E. (1956). The Surface Reactions of Silicate Minerals: The Reactions of Feldspar Surfaces with Acidic Solutions. Agricultural Experiment Station, College of Agriculture, University of Missouri, USA, Bulletin 613.Google Scholar
Nilsson, A., & Book, S. A. (1987). Occurrence and distribution of bone tumors in beagle dogs exposed to 90Sr. Acta Oncologica, 26, 133138.CrossRefGoogle ScholarPubMed
Nolin, D. (1997). Rétention de radioéléments à vie longue par des matériaux argileux. Influence d'anions contenus dans les eaux naturelles. Ph.D. dissertation, Universite Pierre et Marie Curie, Paris 6, France.Google Scholar
Nordberg, G. F. (2004). Cadmium and health in the 21st century–historical remarks and trends for the future. Biometals, 17, 485489.CrossRefGoogle ScholarPubMed
Norrish, K., & Quirk, J. P. (1954). Crystalline swelling of montmorillonite: Use of electrolytes to control swelling. Nature, 173, 255256.CrossRefGoogle Scholar
Oueslati, W., Rhaiem, H. B., & Amara, A. B. H. (2011). XRD investigations of hydrated homoionic montmorillonite saturated by several heavy metal cations. Desalination, 271, 139149.CrossRefGoogle Scholar
Oueslati, W., Rhaiem, H. B., & Amara, A. B. H. (2012). Effect of relative humidity constraint on the metal exchanged montmorillonite performance: An XRD profile modeling approach. Applied Surface Science, 261, 396404.CrossRefGoogle Scholar
Oueslati, W., Chorfi, N., & Abdelwahed, M. (2017). Effect of mechanical constraint on the hydration properties of Namontmorillonite: Study under extreme relative humidity conditions. Powder Diffraction, 32, S160–S167.CrossRefGoogle Scholar
Peynet, V. (2003). Rétention d'actinides et de produits de fission par des phases solides polyminérales. Ph.D. dissertation, Universite Paris 6, France.Google Scholar
Pils, J. R., Laird, D. A., & Evangelou, V. P. (2007). Role of cation demixing and quasicrystal formation and breakup on the stability of smectitic colloids. Applied Clay Science, 35, 201211.CrossRefGoogle Scholar
Poli, A. L., Batista, T., Schmitt, C. C., Gessner, F., & Neumann, M. G. (2008). Effect of sonication on the particle size of montmorillonite clays. Journal of Colloid and Interface Science, 325, 386390.CrossRefGoogle ScholarPubMed
Pinot, F., Kreps, S. E., Bachelet, M., Hainaut, P., Bakonyi, M., & Polla, B. S. (2000). Cadmium in the environment: Sources, mechanisms of biotoxicity, and biomarkers. Reviews on Environmental Health, 15, 299324.CrossRefGoogle ScholarPubMed
Reijonen, H. M., & Alexander, W. R. (2015). Bentonite analogue research related to geological disposal of radioactive waste: Current status and future outlook. Swiss Journal of Geosciences, 108, 101110.CrossRefGoogle Scholar
Robin, V., Tertre, E., Beaucaire, C., Regnault, O., & Descostes, M. (2017). Experimental data and assessment of predictive modeling for radium ion-exchange on beidellite, a swelling clay mineral with a tetrahedral charge. Applied Geochemistry, 85, 19.CrossRefGoogle Scholar
Robin, V., Tertre, E., Beaufort, D., Regnault, O., Sardini, P., & Descostes, M. (2015). Ion exchange reactions of major inorganic cations (H+, Na+, Ca2+, Mg2+ and K+) on beidellite: Experimental results and new thermodynamic data-base. Toward a better prediction of contaminant mobility in natural environments. Applied Geochemistry, 59, 7484.CrossRefGoogle Scholar
Salles, F., Bildstein, O., Douillard, J. M., Jullien, M., & Van Damme, H. (2007). Determination of the driving force for the hydration of the swelling clays from computation of the hydration energy of the interlayer cations and the clay layer. The Journal of Physical Chemistry C, 111, 1317013176.CrossRefGoogle Scholar
Salles, F., Douillard, J. M., Bildstein, O., Gaudin, C., Prelot, B., Zajac, J., & Van Damme, H. (2013). Driving force for the hydration of the swelling clays: Case of montmorillonites saturated with alkaline-earth cations. Journal of Colloid and Interface Science, 395, 269276.CrossRefGoogle ScholarPubMed
Savoye, S., Beaucaire, C., Grenut, B., & Fayette, A. (2015). Impact of the solution ionic strength on strontium diffusion through the Callovo-Oxfordian clayrocks: An experimental and modeling study. Applied Geochemistry, 61, 4152.CrossRefGoogle Scholar
Schatzberg, P. (1967). Molecular diameter of water from solubility and diffusion measurements. The Journal of Physical Chemistry, 71, 45694570.CrossRefGoogle Scholar
Schoonheydt, R. A., Johnston, C. T., Brigatti, M. F. & Mottana, A. (2011). The surface properties of clay minerals. Pp. 337373 in: Layered Structures and their Application in Advanced Technologies (Brigatti, M.F. and Mottana, A., editors). EMU Notes in Mineralogy, 11, European Mineralogical Union and the Mineralogical Society of Great Britain & Ireland.Google Scholar
Schulthess, C. P. (2005). Soil Chemistry with Applied Mathematics. Trafford, Victoria, British Columbia, Canada.Google Scholar
Schulthess, C. P., & Huang, C. P. (1990). Adsorption of heavy metals by silicon and aluminum oxide surfaces on clay minerals. Soil Science Society of America Journal, 54, 679688.CrossRefGoogle Scholar
Schulthess, C. P., Taylor, R. W., & Ferreira, D. R. (2011). The nanopore inner sphere enhancement effect on cation adsorption: Sodium and nickel. Soil Science Society of America Journal, 75, 378388.CrossRefGoogle Scholar
Siroux, B., Beaucaire, C., Tabarant, M., Benedetti, M. F., & Reiller, P. E. (2017). Adsorption of strontium and caesium onto an Na-MX80 bentonite: Experiments and building of a coherent thermodynamic modelling. Applied Geochemistry, 87, 167175.CrossRefGoogle Scholar
Smith, D. W. (1977). Ionic hydration enthalpies. Journal of Chemical Education, 54, 540.CrossRefGoogle Scholar
Starichenko, V. I. (2011). Accumulation of 90Sr in the bone tissue of northern mole voles in the head portion of the East Ural Radioactive Trace. Russian Journal of Ecology, 42, 6470.CrossRefGoogle Scholar
Tajeddine, L., Gailhanou, H., Blanc, P., Lassin, A., Gaboreau, S., & Vieillard, P. (2015). Hydration–dehydration behavior and thermodynamics of MX-80 montmorillonite studied using thermal analysis. Thermochimica Acta, 604, 8393.CrossRefGoogle Scholar
Teppen, B. J., & Miller, D. M. (2006). Hydration energy determines isovalent cation exchange selectivity by clay minerals. Soil Science Society of America Journal, 70, 3140.CrossRefGoogle Scholar
Tertre, E., Beaucaire, C., Coreau, N., & Juery, A. (2009). Modelling Zn (II) sorption onto clayey sediments using a multi-site ion-exchange model. Applied Geochemistry, 24, 18521861.CrossRefGoogle Scholar
Tertre, E., Ferrage, E., Bihannic, I., Michot, L. J., & Prêt, D. (2011). 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, 334347.CrossRefGoogle Scholar
The Clay Mineral Society (2020). Physical and chemical data of source clays, http://www.clays.org/sourceclays_data.html, viewed 2 November 2020.Google Scholar
Tournassat, C., Neaman, A., Villiéras, F., Bosbach, D., & Charlet, L. (2003). Nanomorphology of montmorillonite particles: Estimation of the clay edge sorption site density by low-pressure gas adsorption and AFM observations. American Mineralogist, 88, 19891995.CrossRefGoogle Scholar
Tournassat, C., Ferrage, E., Poinsignon, C., & Charlet, L. (2004a). The titration of clay minerals: II. Structure-based model and implications for clay reactivity. Journal of Colloid and Interface Science, 273, 234246.CrossRefGoogle ScholarPubMed
Tournassat, C., Greneche, J. M., Tisserand, D., & Charlet, L. (2004b). The titration of clay minerals: I. Discontinuous backtitration technique combined with CEC measurements. Journal of Colloid and Interface Science, 273, 224233.CrossRefGoogle ScholarPubMed
Tournassat, C., Bizi, M., Braibant, G., & Crouzet, C. (2011). Influence of montmorillonite tactoid size on Na–Ca cation exchange reactions. Journal of Colloid and Interface Science, 364, 443454.CrossRefGoogle ScholarPubMed
Van Spronsen, M. A., Frenken, J. W., & Groot, I. M. (2017). Observing the oxidation of platinum. Nature Communications, 8, 17.CrossRefGoogle ScholarPubMed
Wissocq, A., Beaucaire, C., & Latrille, C. (2018). Application of the multi-site ion exchanger model to the sorption of Sr and Cs on natural clayey sandstone. Applied Geochemistry, 93, 167177.CrossRefGoogle Scholar
Xia, M., Jiang, Y., Zhao, L., Li, F., Xue, B., Sun, M., Liu, D., & Zhang, X. (2010). Wet grinding of montmorillonite and its effect on the properties of mesoporous montmorillonite. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 356, 19.CrossRefGoogle Scholar
Yu, S., Mei, H., Chen, X., Tan, X., Ahmad, B., Alsaedi, A., Hayat, T. & Wang, X. (2015). Impact of environmental conditions on the sorption behavior of radionuclide 90Sr (II) on Na-montmorillonite. Journal of Molecular Liquids, 203, 3946.CrossRefGoogle Scholar