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Cation exchange capacity methodology II: A modified silver–thiourea method
AbstractThe silver–thiourea method for the determination of the cation exchange capacity (CEC) has been critically examined. The chemical instability of the exchange solution used causes silver sulphide precipitation on the walls of tubes resulting in a loss of the index cation. This produces misinterpretation and yields usually in an overestimation of the CEC. Furthermore, when expandable clay minerals are investigated excess adsorption occurs leading to unreliable CEC results dependent on solution/solid ratio and ionic strength of the exchange solution. A modified silver–thiourea method is proposed, which uses a chemically more stable exchange solution, eliminating silver sulphide precipitation and substantially lowering excess adsorption, which is abolished by additional washings. The results are comparable to the ammonium acetate method.
Cation exchange capacity methodology II: A modified silver–thiourea method
AbstractThe silver–thiourea method for the determination of the cation exchange capacity (CEC) has been critically examined. The chemical instability of the exchange solution used causes silver sulphide precipitation on the walls of tubes resulting in a loss of the index cation. This produces misinterpretation and yields usually in an overestimation of the CEC. Furthermore, when expandable clay minerals are investigated excess adsorption occurs leading to unreliable CEC results dependent on solution/solid ratio and ionic strength of the exchange solution. A modified silver–thiourea method is proposed, which uses a chemically more stable exchange solution, eliminating silver sulphide precipitation and substantially lowering excess adsorption, which is abolished by additional washings. The results are comparable to the ammonium acetate method.
Cation exchange capacity methodology II: A modified silver–thiourea method
Dohrmann, R. (Autor:in)
Applied Clay Science ; 34 ; 38-46
06.02.2006
9 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Cation exchange capacity methodology II: A modified silver–thiourea method
| Online Contents | 2006
Cation exchange capacity methodology II: A modified silver–thiourea method
| British Library Conference Proceedings | 2006
| British Library Conference Proceedings | 2006