Changes in U(VI) speciation upon sorption onto montmorillonite from aqueous and organic solutions

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5119404

Chisholm-Brause, C; Morris, D E; Eller, P G; Buscher, T; Conradson, S D

The speciation of UO{sub 2}{sup 2+} and UO{sub 2}{sup 2+} Tributylphosphate (TBP) mixtures has been investigated in solution and intercalated with the reference smectite clay SAz-1 using x-ray absorption, Raman, and luminescence spectroscopies. Neither aquated UO{sub 2}{sup 2+} nor its TBP complex undergoes any detectable changes in uranium oxidation state on intercalation. Further, at the pH values employed in this work, there is no evidence for hydrolysis of the uranium species to generate dimeric or higher order uranium oligomers. However, we do find indications that the structures of the solution complexes are altered on intercalation, particularly for the UO{sub 2}{sup 2+}/TBP system. In addition, several lines of evidence suggest that, at the loading levels used in this study, the uranyl species may be interacting with two or more spectroscopically distinguishable sites on SAz-1. 29 refs., 3 figs., 2 tabs.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5119404
• Report Number(s): LA-UR-91-3175; CONF-911123--1; ON: DE92002420
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
54 ENVIRONMENTAL SCIENCES
540230 -- Environment
Terrestrial-- Radioactive Materials Monitoring & Transport-- (1990-)
ABSORPTION SPECTROSCOPY
ACTINIDE COMPOUNDS
AQUEOUS SOLUTIONS
BUTYL PHOSPHATES
CATALYSIS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
CLAYS
DIMERIZATION
DISPERSIONS
ESTERS
GEOCHEMISTRY
LASER SPECTROSCOPY
MINERALS
MIXTURES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANIC SOLVENTS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
PHOSPHORIC ACID ESTERS
POLYMERIZATION
RAMAN SPECTROSCOPY
SILICATE MINERALS
SMECTITE
SOLUTIONS
SOLVENTS
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
SURFACE PROPERTIES
TBP
URANIUM COMPOUNDS
URANIUM DIOXIDE
URANIUM OXIDES
VALENCE
X-RAY SPECTROSCOPY