CATION EXCHANGE CAPACITY AND TOTAL ACIDITY OF ALLOPHANE AND VOLCANIC ASH SOILS

Abstract

Absolute cation exchange capacity or total acidity of allophane were determined by barium hydroxide consumption in aqueous suspension and by titration curve with “blank correction”, and obtained more than several hundred milliequivalents per 100g. for the CEC or total acidity and 11.5-11.9 for the pK value. Silanol groups were calculated to be 7-9 per mμ² of allophane surface and all of which were concluded to react with alkalies. Clays other than allophaner silicagels, and soil materials were used for these experiments and the results were discussed together.