Date of Award
Fall 12-18-2020
Degree Type
Thesis
Degree Name
Master of Science (MS)
Department
Geosciences
First Advisor
Dr. W. Crawford Elliott
Second Advisor
Dr. Daniel M. Deocampo
Third Advisor
Dr. Hasan A. Babaie
Fourth Advisor
Dr. Brian A. Powell
Abstract
The Clay Mineral Society SWy-2 Na-montmorillonite clay was reacted for 90 days with 15 mM K+ at 200°C, the temperature/solution conditions of deep geologic repository near-field regions. X-ray diffraction of alteration products indicated that a minor amount of interstratification occurred in the clay. Hydrothermally altered samples sorbed stable Eu and 237Np almost as effectively as the unaltered clay. Average Kd values were 1.79 × 102 kg/L – 2.37 × 105 kg/L (Euonto altered clay), 3.05 × 102 kg/L – 1.54 × 106 kg/L (237Np onto altered clay), 3.55 × 104 kg/L – 1.30 × 106 kg/L (Euonto unaltered clay), and 1.04 × 103 kg/L (237Np onto unaltered clay). Speciation models indicated that Eu(III) and Np(V) complexation was influenced by the presence of chloride and hydroxide, but the largest observed impact on Eu and Np(V) sorption was solution pH which altered the affinity of Eu and Np(V) for the mineral surface.
DOI
https://doi.org/10.57709/19105525
Recommended Citation
Kwong-Moses, Dominique S., "Determining the Effects of Hydrothermal Alteration on the Sorption of Neptunium and Europium onto Bentonites." Thesis, Georgia State University, 2020.
doi: https://doi.org/10.57709/19105525
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