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Title: Chemical Speciation and Association of Plutonium with Bacteria, Kaolinite Clay, and Their Mixture

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Subsurface Biogeochemical Research (SBR)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER)
OSTI Identifier:
1154307
Resource Type:
Journal Article
Resource Relation:
Journal Name: Environmental Science&Technology; Journal Volume: 41; Journal Issue: 9
Country of Publication:
United States
Language:
English

Citation Formats

Toshihiko,Ohnuki, Takahiro,Yoshida, Takuo,Ozaki, Naofumi,Kozai, Fuminori,Sakamoto, Takuya,Nankawa, Yoshinori,Suzuki, and Arokiasamy J.,Francis. Chemical Speciation and Association of Plutonium with Bacteria, Kaolinite Clay, and Their Mixture. United States: N. p., 2007. Web. doi:10.1021/es061207g.
Toshihiko,Ohnuki, Takahiro,Yoshida, Takuo,Ozaki, Naofumi,Kozai, Fuminori,Sakamoto, Takuya,Nankawa, Yoshinori,Suzuki, & Arokiasamy J.,Francis. Chemical Speciation and Association of Plutonium with Bacteria, Kaolinite Clay, and Their Mixture. United States. doi:10.1021/es061207g.
Toshihiko,Ohnuki, Takahiro,Yoshida, Takuo,Ozaki, Naofumi,Kozai, Fuminori,Sakamoto, Takuya,Nankawa, Yoshinori,Suzuki, and Arokiasamy J.,Francis. Tue . "Chemical Speciation and Association of Plutonium with Bacteria, Kaolinite Clay, and Their Mixture". United States. doi:10.1021/es061207g.
@article{osti_1154307,
title = {Chemical Speciation and Association of Plutonium with Bacteria, Kaolinite Clay, and Their Mixture},
author = {Toshihiko,Ohnuki and Takahiro,Yoshida and Takuo,Ozaki and Naofumi,Kozai and Fuminori,Sakamoto and Takuya,Nankawa and Yoshinori,Suzuki and Arokiasamy J.,Francis},
abstractNote = {},
doi = {10.1021/es061207g},
journal = {Environmental Science&Technology},
number = 9,
volume = 41,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}
  • Radioactive strontium ({sup 90}Sr) is an important constituent of the complex wastes from past nuclear weapons production and has been stored in underground tanks at U.S. DOE sites (e.g., Hanford, WA). Using bulk and microfocused EXAFS spectroscopy, we examined temporal changes in solid-phase Sr speciation in kaolinite samples reacted for 1-369 d with high-pH, high ionic strength synthetic tank-waste leachate containing Sr{sup 2+} and Cs{sup +} at 10{sup -3} mol kg{sup -1}. Analyses of bulk EXAFS spectra showed that Sr initially forms a precipitate by 7 d with a local structure similar to SrCO{sub 3}(s). At 33 d, microfocused EXAFSmore » of individual particles in one sample revealed a mixture of hydrated and dehydrated Sr associated with neoformed sodalite-type phases. At aging times of 93 d and longer, bulk EXAFS spectra and supporting characterizations indicated nonexchangeable Sr with a local structure consistent with incorporation into increasingly crystalline aluminosilicate particles, particularly sodalite. These experimental studies suggest that irreversible trapping of radionuclides occurs if they are present during the formation and aging of feldspathoid alteration products of local Si-bearing sediment minerals. This may serve as an effective contaminant sequestration mechanism at sites such as Hanford.« less
  • Little spectroscopic evidence exists in the literature describing the surface complexation of cadmium (Cd) and lead (Pb) on kaolinite, the dominant clay mineral present in highly weathered soils of tropical and humid climates. X-ray absorption fine structure (XAFS) spectroscopy data at the Cd K and Pb LIII edges were collected on Cd- and Pb-sorbed kaolinite samples and compared to a suite of reference materials including Pb and Cd sorbed on amorphous (am-)gibbsite. Cadmium formed dominantly (>75%) outer sphere complexes on kaolinite and a small fraction of CdOHCl complexes. In contrast Cd adsorbed as an inner sphere complex on gibbsite, suggestingmore » that the Si tetrahedral sheet hindered Cd sorption to the Al octahedral sheet on kaolinite. Lead formed polymeric complexes, which bonded to kaolinite via edge sharing with surface Al octahedra. Two distinct Pb-Al edge-sharing distances on am-gibbsite, as opposed to one on kaolinite, suggested a similar steric hindrance effect for the surface complexation of polymeric Pb complexes on kaolinite. The results of this study show that the Si tetrahedral sheet limited the surface complexation of Cd and Pb on kaolinite, elevating kaolinite's permanent negative charge properties in retaining these heavy metals at its surface.« less
  • We provide evidence for hexadentate complexes of Pb2+ and Cd2+ with the trihydroxamate siderophore desferrioxamine B (DFO-B) at pH 7.5, and 9.0, respectively. Analysis of the species of Pb2+ and Cd2+ adsorbed at the surface of kaolinite clay under the same pH conditions and in the presence of DFO-B indicate that Pb2+ is sorbed as a metal-siderophore complex while Cd2+ is not.