Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-28T04:14:29.875Z Has data issue: false hasContentIssue false

Charge Density and Na-K-Ca Exchange on Smectites

Published online by Cambridge University Press:  02 April 2024

I. Shainberg
Affiliation:
Institute of Soils and Water, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50-250, Israel
N. I. Alperovitch
Affiliation:
Institute of Soils and Water, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50-250, Israel
R. Keren
Affiliation:
Institute of Soils and Water, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50-250, Israel
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.

Ca-K.-, Na-K-, and Ca-Na-exchange isotherms on four reference smectites were studied. The electric charge on the four smectites was due predominantly to cationic substitution in the octahedral layer and varied between 90 and 122 meq/g (cmole(+)/kg) clay. The affinity of the clays for K increased with a decrease in the fraction of K in the exchange phase. The selectivity coefficients of the smectites for K increased with an increase in charge density. The effect was similar in the Na-K- and Ca-K-exchange isotherms. Charge densities on the smectites had no effect on the Ca-Na-exchange isotherm. The electrostatic attraction forces between the platelets increased with increase in charge density. The low hydration energy of adsorbed K was apparently not enough to overcome these attraction forces as the charge density on the smectites increased. Equilibrium between the low hydration energy of adsorbed K and the electrostatic attraction energies between the platelets is postulated to explain the results.

Type
Research Article
Copyright
Copyright © 1987, The Clay Minerals Society

Footnotes

Contribution No. 1707E, 1986 Series, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel.

References

Blackmore, A. V. and Miller, R. D., 1961 Tactoid size and osmotic swelling in Ca-montmorillonite Soil Sci. Soc. Amer. Proc. 25 169173.CrossRefGoogle Scholar
Bolt, G. H., Summer, M. E. and Kamphorst, A., 1963 A study of equilibria between three categories of potassium in illitic soil Soil Sci. Soc. Amer. Proc. 27 294299.CrossRefGoogle Scholar
Carson, D. C. and Dixon, J. B., 1972 Potassium selectivity in certain montmorillonite soil clays Soil Sci. Soc. Amer. Proc. 36 838843.CrossRefGoogle Scholar
Keren, R., 1979 Na-Ca exchange in the presence of hydroxy Al Clays & Clay Minerals 27 303304.CrossRefGoogle Scholar
Low, P. F., 1980 The swelling of clay: II. Montmorillonites Soil Sci. Soc. Amer. J. 44 667676.CrossRefGoogle Scholar
Murray, R. S. and Quirk, J. P., 1984 The physical swelling of clays in solvents Soil Sci. Soc. Amer. J. 48 865868.Google Scholar
Norrish, K., 1954 The swelling of montmorillonite Disc. Faraday Soc. 18 120134.CrossRefGoogle Scholar
Schramm, L. L. and Kwak, J. C. T., 1982 Influence of exchangeable cation composition on the size and shape of montmorillonite particles in dilute suspension Clays & Clay Minerals 30 4048.CrossRefGoogle Scholar
Shainberg, I. and Kemper, W. D., 1966 Hydration status of adsorbed cations Soil Sci. Soc. Amer. Proc. 30 707713.CrossRefGoogle Scholar
Shainberg, I., Oster, J. D. and Wood, J. D., 1980 Sodium/calcium exchange in montmorillonite and illite suspensions Soil Sci. Soc. Amer. J. 44 960964.CrossRefGoogle Scholar
Shaviv, A., Mattigod, S. V., Pratt, P. F. and Joseph, H., 1985 Potassium exchange in five southern Californian soils with high potassium fixation capacity Soil Sci. Soc. Amer. J. 49 11281133.CrossRefGoogle Scholar
Talibudeen, O. and Goulding, K. W. T., 1983 Charge heterogeneity in the smectites Clays & Clay Minerals 31 3742.CrossRefGoogle Scholar
U.S. Salinity Laboratory Staff (1954) Diagnosis and improvement of saline and alkali soils: U.S. Dept. Agriculture Handbook 60, U.S. Government Printing Office, Washington, D.C., 160 pp.Google Scholar
van Bladel, R., Cavira, G., Laudelout, H. and Serratosa, J. M., 1972 A comparison of the thermodynamic, double-layer theory and empirical studies of the Na-Ca exchange equilibria in clay water systems Proc. Int. Clay Conf., Madrid, Spain, 1972 Madrid Div. Ciencias C.S.I.C 385398.Google Scholar