An in situ method for remediating ¹³⁷Cs-contaminated wetlands using naturally occurring minerals

T. G. Hinton,¹ A. Knox,¹ D. Kaplan,² S. Serkiz,²

¹Savannah River Ecology Laboratory, Drawer E, Aiken, SC 209802, USA
²Westinghouse Savannah River Company, Aiken, SC, USA

Abstract
Cesium's enhanced bioavailability in contaminated wetlands on the U.S. Department of Energy's Savannah River Site (SRS) is thought to be due to the low clay fraction of SRS soils, and that the clay mineralogy is dominated by kaounites.  Remediation of the wetlands is problematic because current technologies are destructive to the sensitive ecosystems.  We tested 11 clay minerals (two micas, a vermiculite, six illites, a kaolinite. and a smectite) for their propensity to sorb and retain ¹³⁷Cs. Two minerals were subsequently chosen as candidates for in situ remediation amendment materials because they had ¹³⁷Cs distribution coefficients (Kd) well in excess of 10,000 ml-g^-1, and desorbed less than 20% of the Cs when mixed   in a 0.1 M NH₄CI solution. Incremental additions of the candidate minerals to  ¹³⁷ Cs-contaminated sediments appreciably intercepted and retained desorbed  ¹³⁷Cs in the presence of high levels of NH4. Implications for using the minerals as a nondestructive, in situ remediation technique are discussed.

SREL Reprint #2538

Hinton, T. G., K. A., D. Kaplan, and S. Serkiz. 2001. An in situ method of remediating 137Cs-contaminated wetlands using naturally occurring minerals. Journal of Radioanalytical and Nuclear Chemistry 249:197-202.

To request a reprint