Charge properties of some clays from soils with variable charge
| Autor: | Madrid, Luis, Díaz Barrientos, Encarnación, Cabrera, Francisco, Arambarri, Pablo de, Balbontín, J. |
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| Rok vydání: | 1982 |
| Předmět: | |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | 7 páginas, 3 figuras, 3 tablas, 14 referencias. The pH-dependence of surface charge density of the clay fraction of five horizons of a variable-charge soil has been studied by adsorption of potential-determining ions (p.d.i.) and by adsorption of electrolyte ions. In samples with a high proportion of clay minerals (mainly illite) it is not possible to reach the point of zero charge, but samples with lower contents in clay minerals and a higher proportion of metal oxides show a well-defined PZC. Adsorption of p.d.i. by those samples with a low content of clay minerals can be satisfactorily described by a model which considers a three - plane distribution of the electric potential. Some deviations found at acid pH values can be explained by the presence of minerals with a permanent negative charge. Results for adsorption of electrolyte ions are also consistent with the presence of permanent charge. |
| Databáze: | OpenAIRE |
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