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• W2801809306 endingPage "547" @default.
• W2801809306 startingPage "532" @default.
• W2801809306 abstract "Technetium contamination remains a major environmental problem at nuclear reprocessing sites, e.g., the Hanford Site, Washington, USA. At these sites, Tc is present in liquid waste destined for immobilization in a waste form or has been released into the subsurface environment. The high environmental risk associated with Tc is due to its long half-life (214 000 years) and the mobility of the oxidized anionic species Tc(VII)O4–. Under reducing conditions, TcO4– is readily reduced to Tc(IV), which commonly exists as a relatively insoluble and therefore immobile, hydrous Tc-oxide (TcO2·nH2O). The stability of Tc(IV) sequestered as solid phases depends on the solubility of the solid and susceptibility to reoxidation to TcO4–, which in turn depend on the (biogeo)chemical conditions of the environment and/or nuclear waste streams. Unfortunately, the solubility of crystalline TcO2 or amorphous TcO2·H2O is still above the maximum contaminant level (MCL) established by the U.S. EPA (900 pCi/L), and the kinetics of TcO2 oxidative dissolution can be on the order of days to years. In addition to oxygen, sulfur can form complexes that significantly affect the adsorption, solubility, and reoxidation potential of Tc, especially Tc(IV). The principal technetium sulfides are TcS2 and Tc2S7, but much less is known about the mechanisms of formation, stabilization, and reoxidation of Tc-sulfides. A common assumption is that sulfides are less soluble than their oxyhydrous counterparts. Determination of the molecular structure of Tc2S7 in particular has been hampered by the propensity of this phase to precipitate as an amorphous substance. Recent work indicates that the oxidation state of Tc in Tc2S7 is Tc(IV), in apparent contradiction to its nominal stoichiometry. Technetium is relatively immobile in reduced sediments and soils, but in many cases the exact sink for Tc has not been identified. Experiments and modeling have demonstrated that both abiotic and biologic mechanisms can exert strong controls on Tc mobility and that Tc binding or uptake into sulfide phases can occur. These and similar investigations also show that extended exposure to oxidizing conditions results in transformation of sulfide-stabilized Tc(IV) to a Tc(IV)O2-like phase without formation of measurable dissolved TcO4–, suggesting a solid-state transformation in which Tc(IV)-associated sulfide is preferentially oxidized before the Tc(IV) cation. This transformation of Tc(IV)-sulfides to Tc(IV)-oxides may be the main process that limits remobilization of Tc as Tc(VII)O4–. The efficacy of the final waste form to retain Tc also strongly depends on the ability of oxidizing species to enter the waste and convert Tc(IV) to Tc(VII). Many waste form designs are reducing (e.g., cementitious waste forms such as salt stone) and, therefore, attempt to restrict access of oxidizing species such that diffusion is the rate-limiting step in remobilization of Tc." @default.
• W2801809306 created "2018-05-17" @default.
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• W2801809306 date "2018-05-08" @default.
• W2801809306 modified "2023-09-26" @default.
• W2801809306 title "Technetium Stabilization in Low-Solubility Sulfide Phases: A Review" @default.
• W2801809306 cites W11903991 @default.
• W2801809306 cites W1503933299 @default.
• W2801809306 cites W1539366377 @default.
• W2801809306 cites W1596421938 @default.
• W2801809306 cites W180723877 @default.
• W2801809306 cites W1963766639 @default.
• W2801809306 cites W1964203679 @default.
• W2801809306 cites W1964210869 @default.
• W2801809306 cites W1964830212 @default.
• W2801809306 cites W1965862312 @default.
• W2801809306 cites W1966460349 @default.
• W2801809306 cites W1966935167 @default.
• W2801809306 cites W1968252730 @default.
• W2801809306 cites W1968588942 @default.
• W2801809306 cites W1971331133 @default.
• W2801809306 cites W1972101304 @default.
• W2801809306 cites W1979950159 @default.
• W2801809306 cites W198112206 @default.
• W2801809306 cites W1981461090 @default.
• W2801809306 cites W1988577472 @default.
• W2801809306 cites W1991496004 @default.
• W2801809306 cites W1993964276 @default.
• W2801809306 cites W1994821405 @default.
• W2801809306 cites W1995207224 @default.
• W2801809306 cites W2000952907 @default.
• W2801809306 cites W2004017522 @default.
• W2801809306 cites W2004202562 @default.
• W2801809306 cites W2006073002 @default.
• W2801809306 cites W2007312395 @default.
• W2801809306 cites W2008541122 @default.
• W2801809306 cites W2014648758 @default.
• W2801809306 cites W2018125903 @default.
• W2801809306 cites W2019947904 @default.
• W2801809306 cites W2020778130 @default.
• W2801809306 cites W2021320531 @default.
• W2801809306 cites W2024151781 @default.
• W2801809306 cites W2025570880 @default.
• W2801809306 cites W2025736763 @default.
• W2801809306 cites W2029972303 @default.
• W2801809306 cites W2033859133 @default.
• W2801809306 cites W2037774503 @default.
• W2801809306 cites W2041275855 @default.
• W2801809306 cites W2043081799 @default.
• W2801809306 cites W2043221043 @default.
• W2801809306 cites W2044142813 @default.
• W2801809306 cites W2044213852 @default.
• W2801809306 cites W2045675415 @default.
• W2801809306 cites W2047033656 @default.
• W2801809306 cites W2048848169 @default.
• W2801809306 cites W2050340608 @default.
• W2801809306 cites W2052734120 @default.
• W2801809306 cites W2053085449 @default.
• W2801809306 cites W2053111213 @default.
• W2801809306 cites W2054788533 @default.
• W2801809306 cites W2060426501 @default.
• W2801809306 cites W2067622049 @default.
• W2801809306 cites W2069355522 @default.
• W2801809306 cites W2074226774 @default.
• W2801809306 cites W2078420479 @default.
• W2801809306 cites W2080328742 @default.
• W2801809306 cites W2080628565 @default.
• W2801809306 cites W2081095733 @default.
• W2801809306 cites W2081317649 @default.
• W2801809306 cites W2085348992 @default.
• W2801809306 cites W2092899057 @default.
• W2801809306 cites W2094816458 @default.
• W2801809306 cites W2097109130 @default.
• W2801809306 cites W2100531439 @default.
• W2801809306 cites W2112446333 @default.
• W2801809306 cites W2117885339 @default.
• W2801809306 cites W2133293143 @default.
• W2801809306 cites W2142144535 @default.
• W2801809306 cites W2143781094 @default.
• W2801809306 cites W2144950249 @default.
• W2801809306 cites W2145818582 @default.
• W2801809306 cites W2147542863 @default.
• W2801809306 cites W2150797990 @default.
• W2801809306 cites W2150950804 @default.
• W2801809306 cites W2154242761 @default.
• W2801809306 cites W2154748461 @default.
• W2801809306 cites W2159542824 @default.
• W2801809306 cites W2301044713 @default.
• W2801809306 cites W2302387994 @default.
• W2801809306 cites W2314511103 @default.
• W2801809306 cites W2320397014 @default.
• W2801809306 cites W2322735803 @default.

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