Colloid-Facilitated Transport of Radionuclides through the Vadose Zone
This project seeks to improve the basic understanding of the role of colloids in facilitating the transport of contaminants in the vadose zone. We focus on three major thrusts: (1) thermodynamic stability and mobility of colloids formed by reactions of sediments with highly alkaline tank waste solutions, (2) colloid-contaminant interactions, and (3) in situ colloid mobilization and colloid-facilitated contaminant transport occurring in both contaminated and uncontaminated Hanford sediments. The specific objectives that will be addressed are: (1) Determine the liability and thermodynamic stability of colloidal materials, which form after reacting Hanford sediments with simulated Hanford Tank Waste. (2) Determine the potential of Hanford sediments for in situ mobilization of colloids for different types of sediments and different leaching scenarios. (3) Characterize the interactions between initially-formed colloids, their dissolution/alteration products, and native colloidal particles with contaminants in batch experiments under various ionic strength and pH conditions. (4) Evaluate colloid-facilitated radionuclide transport through sediments under different degrees of water saturation in packed and undisturbed sediment columns. (5) Implement colloid-facilitated contaminant transport mechanisms and thermodynamic stability constants into a reactive chemical transport model, and verify model simulations with experimental transport data. Results of this project will help to understand the fundamental mechanisms of Cs transport under the leaking Hanford tanks, and thus contribute to the long-term clean-up strategies at the Hanford site.
- Research Organization:
- Washington State University, Pullman, WA (US); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); University of Tennessee, Knoxville, TN (US); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC) (US)
- DOE Contract Number:
- FG07-02ER62882; FG07-02ER63496
- OSTI ID:
- 836447
- Report Number(s):
- EMSP-86814-2003A; R&D Project: EMSP 86814; TRN: US200503%%701
- Resource Relation:
- Other Information: PBD: 13 Jun 2002
- Country of Publication:
- United States
- Language:
- English
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Colloid-Facilitated Transport of Radionuclides through the Vadose Zone
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