Interfacial Soil Chemistry of Radionuclides in the Unsaturated Zone

[摘要] A number of previous studies focused on dissolution and precipitation rates of clay systems in acidic to neutral conditions without the presence of radionuclides (1-5). However, there is lack of information concerning sorption, dissolution and precipitation kinetics of clays at high pH and ionic strength with radionuclides present, which is representative of the actual conditions in the study area. We are focusing on the behavior of clays and sediments under these geochemical conditions by: (1) investigating dynamics of Cs and Sr uptake over time during the reaction of synthetic tank waste leachate (STWL) with specimen clays and Hanford sediments through batch experiments (2) studying the weathering behavior of clays and Hanford sediments under the extreme geochemical conditions imposed by STWL (3) investigating the dissolution and precipitation behavior of layer silicates using XRD, SEM/EDS, FTIR, TG/DTA, AFM and HRTEM and (4) investigating the surface chemistry and sorption sites of clay minerals using XPS, NMR and XAFS.

[发布日期] 2001-06-01 [发布机构] The Pennsylvania State University, Science Program, University Park, PA (United States)

[关键词] Weathering;X-Ray Diffraction;Sediments;X-Ray Photoelectron Spectroscopy;37 Inorganic, Organic, Physical And Analytical Chemistry