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 Brown, R. E. Articles by Miller, R. H. Search for Related Content PubMed Articles by Brown, R. E. Articles by Miller, R. H. Agricola Articles by Brown, R. E. Articles by Miller, R. H.

Reactions of ¹⁴⁴Ce in Solution and Suspensions of Soil Humie Acid and Bentonite¹

ABSTRACT

A study was made of the formation of radiocolloids by ¹⁴⁴Ce and the adsorption of Ce by equilibrated suspensions of humic acid, bentonite clay, and a mixture of these two colloids saturated with either Ca or K and H. The availability of Ce in these suspensions was measured using excised roots. Ionic strength, Ce concentration, and pH were critical factors affecting the equilibrium between radiocolloidal and monomeric Ce. As ionic strength and Ce concentration decrease and as pH increases the equilibrium is shifted towards the radiocolloidal form of Ce. At pH 6.5 and ionic strength 10^-3 about 90% of the Ce in a solution is in the radiocolloidal form. A multiple regression equation was presented which showed the effects of pH, ionic strength, and Ce concentration on the formation of radiocolloidal Ce in salt solutions. Humic acid adsorbed much greater amounts of ¹⁴⁴Ce and restricted uptake by barley and soybean roots more than did bentonite in the Ca-H saturated system. However, humic acid and bentonite adsorbed similar amounts of ¹⁴⁴Ce in the K-H saturated systems. Mixing bentonite and humic acid produced a synergistic-type effect in regard to Ce adsorption. It was proposed that the strong bonding of Ce by Ca-humic acid and humic acid-bentonite mixtures resulted from a more favorable orientation of the humic acid molecule for chelation of Ce.

¹ Published with permission of the Director of the Ohio Agr. Res. & Devel. Center as Journal Article no. 3-69. A portion of the results were presented before Div. S-2, Soil Science Society of America, Stillwater, Okla., Aug. 23, 1966. The results were used by the senior author in partial fulfillment of the requirements for the M.S. degree. The Ohio State University, 1968. Supported by Public Health Service Research grant RH00124 from the Division of Radiological Health.

² Research Associate and Associate Professors, respectively, The Ohio Agr. Res. & Devel. Center and Ohio State University.

Received for publication March 27, 1969. Accepted for publication May 5, 1969.