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פותח על ידי קלירמאש פתרונות בע"מ -
Effect of Na-hexametaphosphate on the hydraulic conductivity of kaolinite-sand mixtures
Year:
1991
Source of publication :
Clays and Clay Minerals
Authors :
אלפרוביץ', נחמן
;
.
לוי, גיא
;
.
שיינברג, יצחק
;
.
Volume :
39
Co-Authors:
Levy, G.J., Institute of Soils and Water, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Shainberg, I., Institute of Soils and Water, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Alperovitch, N., Institute of Soils and Water, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Van Der Merwe, A.J., Soil and Irrigation Research Institute, Private Bag X79, Pretoria 0001, South Africa
Facilitators :
From page:
131
To page:
136
(
Total pages:
6
)
Abstract:
Mixtures of kaolinite clay and quartz sand were packed in columns and leached with NaCI- CaC12 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 day 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 diffuse 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. © 1991, The Clay Minerals Society.
Note:
Related Files :
Breweries
Dispersion (waves)
Distilled water
electrolyte concentration
Leaching solution
Sand
Sodium adsorption ratio
עוד תגיות
תוכן קשור
More details
DOI :
10.1346/CCMN.1991.0390203
Article number:
0
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
27653
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:32
Scientific Publication
Effect of Na-hexametaphosphate on the hydraulic conductivity of kaolinite-sand mixtures
39
Levy, G.J., Institute of Soils and Water, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Shainberg, I., Institute of Soils and Water, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Alperovitch, N., Institute of Soils and Water, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel
Van Der Merwe, A.J., Soil and Irrigation Research Institute, Private Bag X79, Pretoria 0001, South Africa
Effect of Na-hexametaphosphate on the hydraulic conductivity of kaolinite-sand mixtures
Mixtures of kaolinite clay and quartz sand were packed in columns and leached with NaCI- CaC12 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 day 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 diffuse 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. © 1991, The Clay Minerals Society.
Scientific Publication
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