Investigation into the extraction speciation of rare-earth radioisotopes from aqueous solution using polyoxometalates

Burton‐Pye, Benjamin P.; Cutler, Cathy S.; Howell, Robertha C.; Francesconi, Lynn C.

doi:10.1016/j.ica.2011.09.022

Cited by 6 publications

(4 citation statements)

References 38 publications

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“…In our previous work, we observed that when the reduced Tc is associated with the POM, for example, when the Tc V is incorporated into a defect site, such as in the α 2 P 2 W 17 , the activity is observed at or near the origin with significant tailing . We have also observed that radiolanthanides incorporated into the defect of α 2 P 2 W 17 exhibit similar ITLC data, where activity remains at the origin . In our work reported here (Figure ) and in the literature, reduced Tc migrates close to the solvent front, R f : 0.9.…”

Section: Resultssupporting

confidence: 83%

Strategies for the Photoreduction of Tc‐99 Pertechnetate to Low‐Valent Tc by Keggin Polyoxometalates

et al. 2020

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Technetium‐99 (half‐life of 2.1 × 105 yrs, βmax = 0.29 MeV) is a hazardous radiological contaminant, which, in its predominant form of pertechnetate (TcO4–), is highly mobile in the environment. Most strategies for the removal of pertechnetate from the environment involve uptake and/or absorption of pertechnetate using resins, clays, cationic metal‐organic frameworks and even thorium borate ceramic like materials. Alternative approaches have involved the reduction and subsequent sequestration of lower valent technetium species using iron, sulfides, or iron sulfides. Our lab has explored this strategy using the lacunary alpha‐2 Wells–Dawson polyoxometalate (α2‐[P2W17O61]10–) to both reduce and sequester lower valent technetium, and we have reported on the ligand features that stabilize the reduced species. In this work we investigate the potential of “plenary” Keggin POMs (XW12O40n–) (X = P, Si, Al, n = 3, 4, 5, respectively) to both reduce TcO4– and stabilize the reduced Tc species. Specifically, we report on the mechanism by which the reduction of technetium occurs and find that PW12, SiW12, and AlW12 promote the reduction of TcO4– to lower valent states. X‐ray absorption spectroscopy was used to confirm a combination of TcIV {in the form of TcO2·2H2O and Tc2(µ‐O)24+} and TcV, which is subsequently complexed into a POM defect as a TcV=O species.

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Section: Resultssupporting

confidence: 83%

Strategies for the Photoreduction of Tc‐99 Pertechnetate to Low‐Valent Tc by Keggin Polyoxometalates

et al. 2020

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“…Tc complexed by the binding site of a Wells‐Dawson POM to form Tc V =O P 2 W 17 O 61 10− is retained at the origin [18] . We have also found similar behavior with radiolanthanides bound into POMs [25] . With no specific binding sites, the plenary POMs (Keggin ions, PW 12 O 40 3− , SiW 12 O 40 4− and AlW 12 O 40 5− ) stabilize Tc(IV), with the Tc 2 (μ‐O) 2 4+ species being the most prevalent [18b] .…”

Section: Resultssupporting

confidence: 66%

“…[18] We have also found similar behavior with radiolanthanides bound into POMs. [25] With no specific binding sites, the plenary POMs (Keggin ions, PW ) stabilize Tc(IV), with the Tc 2 (μ-O) 2 4 + species being the most prevalent. [18b] This small polymeric Tc(IV) species migrates with the solvent front with a R f of 0.9, consistent with our current results.…”

Section: Lr Tcmentioning

confidence: 99%

Reduction of Pertechnetate by Chemical and Photochemical Approaches and Incorporation of Tc(IV) into Titanium Dioxide

et al. 2022

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Technetium-99 is a prevalent fission product from nuclear waste. The long half-life (211,000 yr) and environmental mobility of pertechnetate (TcO 4 À ) render Tc particularly challenging to isolate and stabilize. Here we present two approaches for development of potential wasteforms using titanium dioxide, TiO 2 . Approach 1 is a low temperature chemical synthesis of TiO 2 doped with Tc(IV) from TcO 4 À intended to mimic the Tc waste stream from the UREX family of separations and removes 98.5 % of the Tc, mainly present as edge-shared Tc(IV) pairs. Approach 2 utilizes TiO 2 to photocatalytically reduce TcO 4 À to Tc(IV) stabilized on the surface of or within the TiO 2 lattice. The %Tc removed from solution and adsorbed to TiO 2 is pH dependent, with the maximum Tc(IV) adsorbed at pH 3-4 as either TcO 2 or edge-sharing Tc(IV) octahedra. The Tc(IV)-TiO 2 composites materials formed by both approaches are suitable for consolidation into a dense wasteform by Hot Isostatic Pressing (HIPing).

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“…Neutron bombardment in a low power research reactor has been used 42 to make iodine-131, proton bombardment of lanthanum used to make 43 isotopes of cerium (mostly Ce137m) and when natural praseodymium is subjected to a carbon-12 beam 44 gadolinium-149 results. Enriched targets 45 (e.g., in ytterbium-176) have been developed 46…”

Section: Isotope Productionmentioning

confidence: 99%

Radiochemistry

Urch

2013

Annu. Rep. Prog. Chem., Sect. A: Inorg. Chem.

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In this year's review of recent progress in radiochemistry, new radiochemical methods for isotope production, advances in labelling procedures, radioactive isotopes in the environment and miscellaneous topics of radiochemical interest, will be covered but not radiation chemistry, neutron activation analysis and the chemistry of elements that happen to be radioactive. HighlightsThe incorporation of radioisotopes into, sometimes onto, nanoparticles, is becoming increasingly important in nuclear medicine, for therapy and also in diagnosis (ref. 108, 109, 148, 149, 153 and 261-264). Another important piece of work was the use of density functional theory to predict the properties and behaviour of a labelled molecule (ref. 130). General introductionIt is with great sadness that the death of Michael J. Welch in May of 2012 must be recorded. He it was who brought radiochemistry to the medical world, who demonstrated, to a sceptical audience, the potential that radioactive molecules had, when combined with tomography, for diagnosis and tumour location. For forty years he ceaselessly developed nuclear medicine, extending its range to more and more positron emitting isotopes and developing new chemical ways of incorporating them into increasingly complex bio-molecules, 'radiopharmaceuticals'.No new books on radiochemistry in 2012, but a review 1 of the discovery of artificial radioactivity and the report 2 of a conference on the synthesis and applications of labelled compounds have been published. Other conferences have been more focused on specific aspects of the preparation and uses of radioactive compounds, for medical diagnosis and therapy, 3 for autoradiography 4 and to study drug metabolism. 5 A history of the use of radio-iodine has published 6 and the design of bifunctional chelating molecules, 7,8 which can both encapsulate a radioactive atom and join benignly (one hopes so) to a protein or other bio-molecule, reviewed.

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Investigation into the extraction speciation of rare-earth radioisotopes from aqueous solution using polyoxometalates

Cited by 6 publications

References 38 publications

Strategies for the Photoreduction of Tc‐99 Pertechnetate to Low‐Valent Tc by Keggin Polyoxometalates

Strategies for the Photoreduction of Tc‐99 Pertechnetate to Low‐Valent Tc by Keggin Polyoxometalates

Reduction of Pertechnetate by Chemical and Photochemical Approaches and Incorporation of Tc(IV) into Titanium Dioxide

Radiochemistry

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