Organometallic functionalized clays for technetium immobilization

Organometallic functionalized clays for technetium immobilization

Nuclear waste repository designs require backfill materials to contain long-lived radionuclides, including technetium-99, present as the pertechnetate anion (TcO4−) under oxic repository conditions and mobile in the environment. Bentonite has been proposed as a suitable backfill material, and it is...

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Bibliographic Details
Published in:Applied clay science Vol. 261; no. C; p. 107588
Main Authors: Maulden, Emily, Gager, Elizabeth, Ta, An T., Wood, Rachel F., Boglaienko, Daria, Nino, Juan C., Pearce, Carolyn I., Phillpot, Simon R., Szecsody, James E., Wall, Nathalie A.
Format: Journal Article
Language:English
Published: Netherlands Elsevier B.V 01-12-2024
Elsevier
Subjects:
Copper
Montmorillonite
Organoclay
Pertechnetate
Zirconium
Zirconium
Montmorillonite
Copper
Pertechnetate
Organoclay
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Summary:Nuclear waste repository designs require backfill materials to contain long-lived radionuclides, including technetium-99, present as the pertechnetate anion (TcO4−) under oxic repository conditions and mobile in the environment. Bentonite has been proposed as a suitable backfill material, and it is composed of montmorillonite clay, which can be functionalized to optimize its performance for TcO4− sorption. In the current work, bentonite clay is functionalized with organic and inorganic moieties, and the impact of dual functionalization on TcO4− sorption is investigated. The results show that the ordering of the functionalization is essential and that adding metal to an organoclay improves TcO4− sorption compared to either the reverse ordering or the organic/inorganic clay alone. Furthermore, the TcO4− sorption to the organometallic clays was consistent with either chemisorption or cooperative sorption, with a multi-step mechanism determining the kinetics of sorption. [Display omitted] •Bentonite clay backfill functionalized for TcO4− sorption.•Adding metal to organoclay improves TcO4− sorption compared to functionalizing clay-metal system.•TcO4− –organometallic clay sorption consistent with cooperative sorption or chemisorption.•Sorption consistent with a multi-step mechanism determining sorption kinetics.
Bibliography:USDOE Office of Nuclear Energy (NE)
31310021\u202FM0036; 20-19198
ISSN:0169-1317
DOI:10.1016/j.clay.2024.107588