Extraction of U(VI) from Perchlorate Solutions with Diantipyrylmethane Derivatives

Extraction of U(VI) from perchlorate solutions with diantipyrylmethane derivatives in chloroform and dichloroethane is studied. The composition of extractable complexes is [UO₂L₂](ClO₄)₂. The extraction constants are estimated. The maximal extractive power is shown by diantipyrylmethane in dichloroethane. Introduction of substituents at the methylene carbon of the extractant molecule makes the extraction worse.     

Extraction of U(VI) with antipyrine in the presence of aminone pyrazolone dye

Extraction of U(VI) with a solution of antipyrine in chloroform in the presence of aminone [a pyrazolone dye, di(p-dimethylaminophenyl)(1-p-sulfophenyl-3-methylpyrazol-5-on-4-yl)carbinol ammonium salt] was studied. A procedure was suggested for extraction-chromatographic determination of 2–30 μg of U(VI). The extractable complex has the composition UO₂L₂A₂; ?₄₇₀ = 4.5 × 10⁴. Th, Sc, In, Fe(III), REE, Zr, Mo(VI), and some other elements in a 500-fold molar excess do not interfere with the determination.     

Sorption-barrier properties of granitoids and andesite-basaltic metavolcanites with respect to Am(III) and Pu(IV): 1. Absorption of Am and Pu from groundwater on monolithic samples of granitoids and andesite-basaltic metavolcanites

A model study is made of the sorption-barrier properties of intact monolithic samples of granitoids and andesite-basaltic metavolcanites with respect to Am(III) and Pu(IV). In sorption from simulated groundwater (pH 8.3), the surface distribution coefficient in surface sorption K _a was determined to be 8–37 and 4–80 cm for Am and Pu, respectively. The mineral components of the rocks responsible for the radionuclide sorption were identified by autoradiography. The rocks tested are characterized by high retention capacity for Am and Pu.     

Effect of colloidal component in solutions on adsorption of actinides [Am(III), Pu(IV)] from simulated groundwater by glass and granodiorite

The effect of the colloidal component in solutions on Am(III) and Pu(IV) adsorption from simulated groundwater on glass and monolithic granitoid samples was examined. For the systems under consideration, the presence of colloids in solutions affects the initial step of Am(III) sorption on glass and rocks, decelerating it. As the system approaches the equilibrium state, the role of the colloidal component becomes less significant. When forecasting conditions of underground isolation of transuranium elements, their colloidal form exhibiting increased migration ability in aqueous solutions should be taken into account.     

Sorption-barrier properties of granitoids and andesite-basaltic metavolcanites with respect to Am(III) and Pu(IV): 2. Absorption of Am and Pu from groundwater on crushed samples of granitoids and andesite-basaltic metavolcanites and also on their rock-forming minerals

A model study is made of the sorption-barrier properties of crushed samples of granitoids and andesite-basaltic metavolcanites with respect to Am(III) and Pu(IV). In sorption from simulated groundwater (pH 8.3), the volume distribution coefficient K _d of Am was determined to be (0.8–1.6) × 10³ and (3.4–7.0) × 10³ cm³ g^?1, and that of Pu, (0.5–1.7) × 10³ and (1.0–10.0) × 10² cm³ g^?1 for metavolcanites and granitoids, respectively, suggesting good sorption-barrier properties of these rocks. The sorption power of the basic rock-forming minerals of granitoids decreases in the order biotite > feldspar > quartz. The results obtained in this study can be used as input data in predicting the rates of Am and Pu migration with groundwater.