Montmorillonite: Effect of pH on Its Adsorption of a Soil Humic Compound

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Science  01 Jul 1966:
Vol. 153, Issue 3731, pp. 70-71
DOI: 10.1126/science.153.3731.70


The d001 spacing of sodium montmorillonite increased from 9.87 to 17.50 angstroms after interaction of the compound with fulvic acid at pH 2.5. The magnitude of the spacing decreased with increase in pH between 2.5 and 6.0. A t pH 2.5 40 milligrams of Namontmorillonite adsorbed 31 mg of fulvic acid; at pH 6.0, only 15.8 mg.