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Effect of Na-Hexametaphosphate on the Hydraulic Conductivity of Kaolinite-Sand Mixtures

Published online by Cambridge University Press:  02 April 2024

G. J. Levy ,
I. Shainberg ,
N. Alperovitch  and
A. J. van der Merwe
G. J. Levy
Affiliation:
Institute of Soils and Water, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
I. Shainberg
Affiliation:
Institute of Soils and Water, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
N. Alperovitch
Affiliation:
Institute of Soils and Water, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
A. J. van der Merwe
Affiliation:
Soil and Irrigation Research Institute, Private Bag X79, Pretoria 0001, Republic of South Africa
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Abstract

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Mixtures of kaolinite clay and quartz sand were packed in columns and leached with NaCl-CaCl2 solutions of different concentrations (ranging from 0.5 M to distilled water) having sodium adsorption ratios (SAR) of 5, 10 and 20. Sodium hexametaphosphate (NaHMP) (10 g/m3) was added to each solution. Changes in the hydraulic conductivity (HC) and clay concentration in the effluent were measured, and the dispersion of the clay was evaluated. In the absence of NaHMP, using distilled water instead of 0.01 M solutions caused some reduction in the HC; the reduction became more severe as the SAR increased. At SAR 20 the HC dropped to 73% of that obtained when the 0.5 M salt solution was used. This reduction in HC was related to increases in the pH of the effluent and partial dispersion of the clay. On adding the NaHMP to the leaching solutions, a marked decrease in the HC and severe clay dispersion were observed at all SAR levels, if the kaolinite-sand mixtures were leached with dilute solutions and distilled water. The HC dropped to 40% of that obtained when leaching with 0.5 M salt solution, and dispersed clay in the effluent peaked at about 1% in the SAR 20 treatment following leaching with distilled water. The observed reduction in the HC of the kaolinite-sand mixture when NaHMP was added to the leaching solutions was due to the dispersive effect of NaHMP and sodium on the kaolinite. The polyanion NaHMP reduced the edge-to-face particle interactions, thereby enabling the dimise double-layer repulsion forces to predominate. Following addition of the polyphosphate, the response of kaolinite to sodium and electrolyte concentration was similar to that reported in the literature for smectite.

Keywords

DispersionHexametaphosphateHydraulic conductivityKaoliniteSandSodium adsorption ratio
Type
Research Article
Information
Clays and Clay Minerals , Volume 39 , Issue 2 , April 1991 , pp. 131 - 136
Copyright
Copyright © 1991, The Clay Minerals Society

Footnotes

1

Contribution from the Soil and Irrigation Research Institute, Private Bag X79, Pretoria 0001, Republic of South Africa.

References

Alperovitch, N., Shainberg, I., Keren, R. and Singer, M. J., 1985 Effect of clay mineralogy and aluminum and iron oxides on the hydraulic conductivity of clay-sand mixtures Clays & Clay Minerals 33 443 – 450.CrossRefGoogle Scholar
Bar-On, P. and Shainberg, I., 1970 Hydrolysis and decomposition of Na-montmorillonite in distilled water Soil Sci. 109 241 – 246.CrossRefGoogle Scholar
Durgin, P. B. and Chaney, J. G., 1984 Dispersion of ka-olinite by dissolved organic matter from Douglas-fir roots Can. J. Soil Sci. 64 445 – 455.CrossRefGoogle Scholar
Flegmann, A. W., Goodwin, J. W. and Ottewill, R. H., 1969 Rheological studies on kaolinite suspensions Proc. Brit. Ceram.Soc. 13 31 – 41.Google Scholar
Norrish, K. and Hutton, J. T., 1969 An accurate x-ray spectrographic method for the analysis of a wide range of geological samples Geochim. Cosmochim. Acta 33 431 – 453.CrossRefGoogle Scholar
Oster, J. D., Shainberg, I. and Wood, J. D., 1980 Floc-culation value and gel structure of Na/Ca montmorillonite and illite suspensions Soil Sci. Soc. Amer. J. 44 955 – 959.CrossRefGoogle Scholar
Quirk, J. P. and Schofield, R. K., 1955 The effect of electrolyte concentration on soil permeability J. Soil Sci. 6 163 – 178.CrossRefGoogle Scholar
Rand, B. and Melton, I. E., 1977 Particle interactions in aqueous kaolinite suspensions. 1. Effect of pH and electrolyte upon the mode of particle interaction in homoionic sodium kaolinite suspensions J. Colloid Interface Sci. 60 308 – 320.CrossRefGoogle Scholar
Schofield, R. K. and Samson, H. R., 1954 Flocculation of kaolinite due to the attraction of oppositely charged crystals faces Disc. Faraday Soc. 18 138 – 145.CrossRefGoogle Scholar
Shainberg, I., Bresler, E. and Klausner, Y., 1971 Studies on Na/Ca montmorillonite systems. I. The swelling pressure Soil Sci. III 214 – 219.CrossRefGoogle Scholar
Shainberg, I., Keren, R., Alperovitch, N. and Goldstein, D., 1987 Effect of exchangeable potassium on the hydraulic conductivity of smectite-sand mixtures Clays & Clay Minerals 35 305 – 310.CrossRefGoogle Scholar
Shainberg, I., Alperovitch, N. and Keren, R., 1988 Effect of magnesium on the hydraulic conductivity of Na-smec-tite-sand mixtures Clays & Clay Minerals 36 432 – 438.CrossRefGoogle Scholar
van Olphen, H., 1977 An Introduction to Clay Colloid Chemistry 2 New York Interscience 92 – 110.Google Scholar