Collboration: Interfacial Soil Chemistry of Radionuclides in the Unsaturated Zone

[摘要] The principal goal of this project was to assess the molecular nature and stability of radionuclide immoblization during weathering reactions in bulk Hanford sediments and their high surface area clay mineral constituents. We focused on the unique aqueous geochemical conditions that are representative of waste-impacted locations in the Hanford site vadose zone; high ionic strength, high pH and high Al concentrations. The specific objectives of the work were to measure the coupling of clay mineral weathering and contaminant uptake kinetics of Cs, Sr and I; determine the molecular structure of contaminant binding sites and their change with weathering time during and after exposure to synthetic tank waste leachate; establish the stability of neoformed weathering products and their sequestered contaminbants upon exposure of the solids to more natural soil solutaions afer remofal of the caustic waste source; and integrate macroscopic, microscopic and spectroscopic data to distinguish labile from non-labile contaminant binding environments, including their dependence on system composition and weathering time.

[发布日期] 2006-12-11 [发布机构] Pennsylvania State University

[关键词] Removal;Surface Area;Sediments;Clays;Molecular Structure