Influence of calcium carbonate content on electrical charges distribution of calcareous soils surfaces [electronic resource].

Includes references.

Four clay minerals were identified in some clay fraction separated from three calcareous soils using x-ray diffraction analysis. Electrophoretic mobility Vel of these fractions was determined at different pH values and CaC03 contents. Zeta potential was computed from Vell values. The charge density was calculated through the cation exchange capacity and the surface area of the soil. The distribution of charges in the electrical double layer of these clay fractions was changed due to their CaC03 contents, and pH. Zeta potential was more pronouncing at lower CaC03 content. The specific adsorption charges (б '1) for the three soils were higher than the nonspecific adsorption charges (б'2) at the lower content of CaC03. This revealed that as CaC03 content decreased the charge density :increased.

Summary in Arabic.

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