HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by van Reeuwijk, L. P. Articles by de Villiers, J. M. Search for Related Content PubMed Articles by van Reeuwijk, L. P. Articles by de Villiers, J. M. Agricola Articles by van Reeuwijk, L. P. Articles by de Villiers, J. M.

Potassium Fixation by Amorphous Aluminosilica Gels¹

ABSTRACT

Synthetic aluminosilica gels fixed potassium in varying amounts against replacement by common alkali and alkaline earth cations; the larger the solvated size of the replacing cation the greater was the amount of K retained. Replacing power thus followed the lyotropic series NH₄ > Na > Ba > Ca > Mg. The amounts of K fixed against exchange by a particular ion increased with total cation-exchange capacity (in turn dependent on gel composition) and with the pH value at which K-saturation originally took place. A marked increase in capacity to fix K was shown to result from drying the gels prior to K-saturation. Drying presumably increased the rigidity of channels in the gel structure which restrict the passage of larger hydrated cations and which, as with zeolites, are responsible for the fixation phenomenon. For xerogels, wet- and dry-fixation measurements yielded results of the same order of magnitude.

¹ Contribution from the Department of Soil Science, University of Natal, Pietermaritzburg, S. Africa. Supported in part by the Department of Agricultural Technical Services of the Republic of South Africa.

² Graduate Assistant on exchange from the State Agricultural University, Wageningen, The Netherlands, and Senior Lecturer, respectively.

Received for publication August 21, 1967. Accepted for publication December 18, 1967.