Publications by authors named "V S Semenishchev"

The work describes an isotope generator of polonium-210 based on an extraction chromatographic resin SR Resin. It was shown that a high selectivity of 4,4'(5')-di-t-butylcyclohexano-18-crown-6, an active component of SR Resin, for lead allows a clear separation of Pb-210 from impurities, easy elution of Po-210 with 5-7 mL of 0.05 M nitric acid solution as well as good retention of Pb-210 in the generator.

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The paper describes a method of recovery of Ac tracer from an old thorium salt through sequential separation of Ra by sorption onto the MnO-CTA disk from thorium solution followed by Ac/Ra separation using the Axionit 507 extraction chromatographic resin. It was shown that the optimal conditions of radium separation from thorium nitrate solution are pH 4.7-6.

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In this work, we have studied sorption of Сs and Sr radionuclides from seawater under batch conditions by ferrocyanide sorbents based on hydrated titanium and zirconium dioxides (Т-35, NPF-HTD), clinoptilolite and glauconite (NPF-GL, NPF-CL) natural aluminosilicates, zirconium phosphate (T-3A), modified hydrated titanium dioxide (T-3K) as well as by manganese dioxide based on hydrated titanium dioxide (MD-HTD). Isotherms of sorption and dependences of cesium distribution coefficients on salt content and calcium concentration were obtained. Distribution coefficients of cesium and strontium were calculated.

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Environmental contamination by uranium (U) and other radionuclides is a serious problem worldwide, especially due to, e.g. mining activities.

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An assessment is given of the possibility of sorbents based on natural aluminosilicates (glauconite and clinoptilolite) being used for remediation of radioactively contaminated land with the aim of returning it to farming use. A comparative study of selectivity and reversibility of radiocaesium and radiostrontium sorption by natural aluminosilicates as well as by modified ferrocyanide sorbents based on these aluminosilicates was made. It was found that surface modification of aluminosilicates by ferrocyanides increases the selectivity of synthesized sorbents to caesium by 100-1000 times, increases sorption capacity and makes caesium sorption almost irreversible, whereas, selectivity of these sorbents to strontium radionuclides remains approximately the same as for natural aluminosilicates.

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