Filled Fibrous Sorbents Modified with Transition Metal Ferro- and Ferricyanides for Recovery of Americium and Rare-Earth Metals

Filled fibrous sorbents modified with transition metal ferro- and ferricyanides capable to recover americium(III) and rare-earth metals(III) from nitric acid solutions were prepared. The most complete and rapid recovery is attained on complex-forming and cation-exchange sorbents (as filled fibrous materials) saturated with nickel ions. The sorbents are characterized by good kinetic properties and can be used for recovery of the above metals.     

Solid-phase extractants based on taunit carbon nanotubes for actinide and REE preconcentration from nitric acid solutions

The sorption properties of solid-phase extractants (SPEs) prepared by impregnation of Taunit carbon nanotubes with adducts of diphenyl(dibutylcarbamoylmethyl)phosphine oxide (CMPO) and tri-n-octylphosphine oxide (TOPO) in HNO₃ solutions were studied. The SPEs exhibit high ability to sorb U(VI), Pu(IV), Np(V), Am(III), and Eu(III) from nitric acid solutions, with good kinetic properties. The impregnation conditions and distribution coefficients of the radionuclides in their recovery from 3 M HNO₃ were determined. The possibility of preparing SPEs by Taunit impregnation in HNO₃ solutions with adducts of tributyl phosphate (TBP) and N,N′-dimethyl-N,N′-dioctylhexylethoxymalonamide (DMDOHEMA) and with Cyphos IL-101 phosphonium ionic liquid was demonstrated.     

Sorption recovery of radionuclides from alkaline solutions using fibrous “filled” sorbents

The possibility of using POLIORGS 33-n and 34-n fibrous “filled” sorbents with amidoxime groups for recovering U(VI), Am(III), and Pu(IV) from alkaline solutions of various compositions was studied. These sorbents exhibit high performance and excellent kinetic properties in recovery of uranium and transuranium elements from alkaline solutions. The distribution coefficients in their sorption from alkaline solutions at various (even high) values of pH and salt content were determined. Original Russian Text N.P. Molochnikova, I.G. Tananaev, G.V. Myasoedova, B.F. Myasoedov, 2007, published in Radiokhimiya, 2007, Vol. 49, No. 1, pp. 58–60.     

Extraction and sorption preconcentration of U(VI), Am(III), and Pu(IV) from nitric acid solutions with alkylenediphosphine dioxides

The extraction of U(VI), Am(III), and Pu(VI) from nitric acid solutions in the form of complexes with alkylenebis(diphenylphosphine) dioxides and their sorption with POLIORGS F-6 sorbent prepared by noncovalent immobilization of methylenebis(diphenylphosphine) dioxide (MDPPD) on a KhAD-7M? polymeric matrix were studied. The preconcentration conditions and distribution coefficients of U(VI), Am(III), and Pu(IV) in their sorption from 3 M HNO₃ were determined. The possibility of concentrating actinides from multicomponent solutions was demonstrated. The composition and nature of complexes of U(VI) with MDPPD were determined from the ³¹P NMR data.     

Sorption preconcentration of radionuclides on Taunit carbon nanostructural material

The possibility of using Taunit carbon nanostructural material for sorption recovery of radionuclides from aqueous solutions was examined. Taunit efficiently recovers Am, Pu, Eu, U, and Tc from weakly acidic and neutral solutions. Taunit is a suitable support for preparing solid extractants based on a phosphonium ionic liquid and diphenyl(dibutylcarbamoylmethyl)phosphine oxide for recovery of actinides from nitric acid solutions.     

Sorption of neptunium in the highest oxidation states from alkaline solutions with complexing fibrous “filled” sorbents

Sorption of Np(VII), Np(VI), and Np(V) from 1 M NaOH by complexing fibrous “filled” sorbents was examined. POLIORGS 33-n and 34-n sorbents containing amidoxime and hydrazidine groups efficiently recover Np in the highest oxidation states and exhibit good kinetic properties. During sorption, Np(VII) is reduced with the sorbent to Np(VI) having a higher, under the actual conditions, distribution coefficient. The distribution coefficients, ml g^?1, were estimated at 4.6 × 10³ for Np(VII), 1.4 × 10⁴ for Np(VI), and 3.6 × 10² for Np(V).     

Preconcentration of uranium on POLIORGS 34-n fibrous filled sorbent from natural waters

Sorption preconcentration of U(VI) on POLIORGS 34-n fibrous filled sorbent with amidoxime groups from model solutions like natural water was studied under static and dynamic conditions. The equilibrium (distribution coefficient) and kinetic (diffusion coefficient) parameters of the sorption were determined. Parameters of dynamic preconcentration of uranium by sorption on disks and in a column packed with POLIORGS 34-n under indicated conditions were calculated by mathematical modeling using the experimental data.