Function of Colloidal and Nanoparticles in the Sorption of Radionuclides

Romanchuk, Anna Yu.; Kalmykov, Stepan N.

doi:10.1007/978-981-15-0679-6_6

Cited by 3 publications

(2 citation statements)

References 95 publications

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“…Knowledge of the speciation and chemical behaviors of intrinsic thorium oxide nanoparticles/colloids has potential implications for the behavior of Th(IV) and, by analogy, An(IV) in the environment. Carrier-or pseudo-colloids formed by the adsorption of actinides onto natural aquatic colloids such as mineral fragments, humic substances and microorganisms might also increase the mobility of Pu(IV) in the far-field environment of a high-level nuclear waste repository (Romanchuk & Kalmykov, 2020;Kersting, 2013;Abdel-Fattah et al, 2013). Colloids, in the form of amorphous or microcrystalline An(OH) 4 (am) or AnO 2 ÁxH 2 O(s), are solubility-limiting phases that play a key role in transporting the actinides to the near-field environment (Dumpala et al, 2021;Nishikawa et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

SAXS study of the formation and structure of polynuclear thorium(IV) colloids and thorium dioxide nanoparticles

Zhai

Tian

et al. 2022

J Synchrotron Rad

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Stable actinide colloids and nanoparticles are of interest because of their potential to affect the transportation of radionuclides in the near-field of a nuclear waste repository. At high concentrations, thorium(IV) can precipitate to form intrinsic colloids. In the present study, polynuclear thorium colloids and thorium dioxide crystallites, formed by the condensation of hydrolyzed Th4+ solutions (3 mM; initial pH 5.5) aged for up to 18 months, were studied using small-angle X-ray scattering. Scattering profiles were fitted using a unified Guinier/power-law model (Beaucage model) to extract the radii of gyration and Porod exponents. Analysis of the scattering profiles from a dispersion aged for 5 months indicated that both polymer coils and more compacted structures (radius of gyration R g ≃ 10 nm) were present, which translated in the Kratky plots as a plateau and a peak maximum, respectively. After 18 months, the SAXS data were consistent with the presence of agglomerates of ThO2 particles suspended in aqueous solution (pH 3.2; [Th] = 1.45 mM). The measured radius of gyration (R g) of the agglomerates was 5.8 nm, whereas the radius of the ThO2 particles was 2.5 nm.

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Section: Introductionmentioning

confidence: 99%

SAXS study of the formation and structure of polynuclear thorium(IV) colloids and thorium dioxide nanoparticles

Zhai

Tian

et al. 2022

J Synchrotron Rad

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“…Various approaches to describe the sorption of radionuclides onto minerals have been discussed for a long time. The interest in this matter never ceased because sorption on environmental minerals is one of the main processes affecting radionuclides and heavy metals transport in the environment (Schindler and Stumm, 1987;Dzombak and Morel, 1990;Hochella and White, 1990;Appelo and Postma, 1993;OECD/NEA, 2012;Geckeis et al, 2013;Kersting, 2013;Payne et al, 2013;Romanchuk and Kalmykov, 2020). Therefore, understanding and numerical description of these processes are essential in the context of radioecology, remediation of contaminated areas, and safety assessment of radioactive waste storage and disposal facilities of different types.…”

Section: Introductionmentioning

confidence: 99%

U(VI), Np(V), Eu(III) sorption on goethite: A wide-ranging multiradionuclide dataset and uncertainty-aware parametrization of surface complexation models

Romanchuk¹,

Svitelman²,

Blinov³

et al. 2022

Front. Nucl. Eng.

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Obtaining reliable thermodynamic sorption data is essential for establishing databases that can be used for the numerical safety evaluations of radioactive waste storage and disposal facilities. For this purpose, new experimental data on the sorption of U(VI), Np(V), and Eu(III) onto synthesized goethite in a wide range of experimental conditions were collected. Thermodynamic surface complexation models based on different approaches were developed and parametrized to fit a large dataset, including experimental data from the current work as well as available literature data. The proposed heuristic optimization procedure allowed identifying and comparing different parametrization variants and their uncertainties for considered models. The developed models pass the test on additional Cd(II) and Zn(II) data, simultaneously providing a reliable description of the sorption process for five cations and could probably be extended using the obtained linear free energy relationship.

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Effect of solution acidity on the crystallization of polychromates in uranyl-bearing systems: synthesis and crystal structures of Rb₂[(UO₂)(Cr₂O₇)(NO₃)₂] and two new polymorphs of Rb₂Cr₃O₁₀

Nazarchuk

Siidra

Charkin

et al. 2021

Zeitschrift Für Kristallographie - Crystalline Materials

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Three new rubidium polychromates, Rb2[(UO2)(Cr2O7)(NO3)2] (1), γ-Rb2Cr3O10 (2) and δ-Rb2Cr3O10 (3) were prepared by combination of hydrothermal treatment at 220 °C and evaporation of aqueous solutions under ambient conditions. Compound 1 is monoclinic, P 2 1 / c $P{2}_{1}/c$ , a = 13.6542(19), b = 19.698(3), c = 11.6984(17) Å, β = 114.326(2)°, V = 2867.0(7) Å3, R 1 = 0.040; 2 is hexagonal, P 6 3 / m $P{6}_{3}/m$ , a = 11.991(2), c = 12.828(3) Å, γ = 120°, V = 1597.3(5) Å3, R 1 = 0.031; 3 is monoclinic, P 2 1 / n $P{2}_{1}/n$ , a = 7.446(3), b = 18.194(6), c = 7.848(3) Å, β = 99.953(9)°, V = 1047.3(7) Å3, R 1 = 0.037. In the crystal structure of 1, UO8 bipyramids and NO3 groups share edges to form [(UO2)(NO3)2] species which share common corners with dichromate Cr2O7 groups producing novel type of uranyl dichromate chains [(UO2)(Cr2O7)(NO3)2]2−. In the structures of new Rb2Cr3O10 polymorphs, CrO4 tetrahedra share vertices to form Cr3O10 2− species. The trichromate groups are aligned along the 63 screw axis forming channels running in the ab plane in the structure of 2. The Rb cations reside between the channels and in their centers completing the structure. The trichromate anions are linked by the Rb+ cations into a 3D framework in the structure of 3. Effect of solution acidity on the crystallization of polychromates in uranyl-bearing systems is discussed.

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Function of Colloidal and Nanoparticles in the Sorption of Radionuclides

Cited by 3 publications

References 95 publications

SAXS study of the formation and structure of polynuclear thorium(IV) colloids and thorium dioxide nanoparticles

SAXS study of the formation and structure of polynuclear thorium(IV) colloids and thorium dioxide nanoparticles

U(VI), Np(V), Eu(III) sorption on goethite: A wide-ranging multiradionuclide dataset and uncertainty-aware parametrization of surface complexation models

Effect of solution acidity on the crystallization of polychromates in uranyl-bearing systems: synthesis and crystal structures of Rb₂[(UO₂)(Cr₂O₇)(NO₃)₂] and two new polymorphs of Rb₂Cr₃O₁₀

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Function of Colloidal and Nanoparticles in the Sorption of Radionuclides

Cited by 3 publications

References 95 publications

SAXS study of the formation and structure of polynuclear thorium(IV) colloids and thorium dioxide nanoparticles

SAXS study of the formation and structure of polynuclear thorium(IV) colloids and thorium dioxide nanoparticles

U(VI), Np(V), Eu(III) sorption on goethite: A wide-ranging multiradionuclide dataset and uncertainty-aware parametrization of surface complexation models

Effect of solution acidity on the crystallization of polychromates in uranyl-bearing systems: synthesis and crystal structures of Rb2[(UO2)(Cr2O7)(NO3)2] and two new polymorphs of Rb2Cr3O10

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Effect of solution acidity on the crystallization of polychromates in uranyl-bearing systems: synthesis and crystal structures of Rb₂[(UO₂)(Cr₂O₇)(NO₃)₂] and two new polymorphs of Rb₂Cr₃O₁₀