SREL Reprint #2212

Determination of site specific binding environments of surface sorbed cesium on clay minerals by Cs-EXAFS

K.M. Kemner1, D.B. Hunter2, P.M. Bertsch2, J.P. Kirkland3, and W.T. Elam1

1Naval Research Laboratory, Code 6685, Washington, DC 20375, USA
2Advanced Analytical Center for Environmental Sciences, University of Georgia/SREL, Aiken SC, USA
3SFA Inc., Landover, MD, USA

Abstract: Transport behavior of 137Cs in the environment is regulated by surface sorption reactions on clay mineral surfaces. To provide greater understanding of Cs transport processes, XAFS investigations of the local environments of 133Cs sorbed to clay minerals were conducted on Cs-Ca exchanged clay suspensions at the Cs LIII-edge. With surface loadings of Cs, the Cs local environment exhibited increased long range order beyond 6 Å. Identification of Cs in expanded, semi-collapsed and collapsed interlayer environments was determined by correlating radial distances and Fourier transform peak amplitudes representing Cs-0 and Cs-Al/Si in the octahedral and tetrahedral layers. Despite the difficulties of analyzing XAFS data of adsorbed atoms in multiple environments, isolation of Cs in more specific sites by selective exchange should allow detailed analysis and identification of predominant binding environments of cations to clay surfaces.

SREL Reprint #2212

Kemner, K.M., D.B. Hunter, B.M. Bertsch, J.P. Kirkland, and W.T. Elam. 1997. Determination of site specific binding environments of surface sorbed cesium on clay minerals by Cs-EXAFS. Journal de Physique IV France 7:777-779.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).