Uranium sorption to natural substrates-insights provided by isotope exchange, selective extraction and surface complexation modelling approaches

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:140973

Waite, T D; Payne, T E ^[1]; Davis, J A ^[2]

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1. Australian Nuclear Science and Technology Organisation, New South Wales (Australia)
2. Geological Survey, Menlo Park, CA (United States)

An extensive experimental program has been conducted over the last three years into the interaction of U(VI) with both single oxides and clays and complex natural substrates from the weathered zone in the vicinity of a uranium ore body in northern Australia. While iron oxides have frequently been considered to account for much of the uptake on such natural substrates, the results of laboratory {open_quotes}pH edge{close_quotes} studies and of isotope exchange and selective extraction studies suggest that other phases must also play a significant role in controlling the partitioning of U(VI) between solid and solution phases. Supporting studies on kaolinite, the dominant clay in this system, provide insight into the most appropriate method of modelling the interaction of U(VI) with these natural substrates. The problems still remaining in adequately describing sorption of radionuclides and trace elements to complex natural substrates are discussed.

• OSTI ID: 140973
• Report Number(s): CONF-930304--
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
EXTRACTION
GEOCHEMISTRY
IRON OXIDES
ISOTOPIC EXCHANGE
KAOLINITE
SORPTION
SUBSTRATES
SURFACE PROPERTIES
URANIUM COMPLEXES