Influence of technetium and rhenium speciation on their sorption on natural sorbents

Natural sorbents are mostly useful for retardation of the radionuclides. In this study, the possibility to apply the natural sorbents as carrier mater ials for radiopharmaceutical in vitro applications has been tested. The sor ption experiments with technetium-99 have been carried out on bentonite R. The K-d values have been determined using the batch method. The results of the comparative study of the determination of the distribution coefficient by radiometric and polarographic methods are discussed from point of view o f sorbed radionuclides speciation. The DPP polarografic reduction of ammoni um pertechnetate and potassium perrhenate has been studied in aqueous solut ion with a variety of supporting electrolytes. The formation of the rhenium and technetium complexes as a function of the aqueous; phase pH has been s tudied by the polarographic method.