Studies on some divalent metal α-isosaccharinic acid complexes
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Peter Warwick
Summary
The presence of organic complexants, such as α-isosaccharinic acid (ISA) in an intermediate-level radioactive-waste (ILW) repository may have a detrimental effect on the sorption of radionuclides by forming organic complexes in solution. To assess this, stability constants are required for the complexes formed. Constants have been determined for the divalent metal ions, Cd2+, Co2+ and UO22+ with α-isosaccharinic acid (ISA) in near-neutral and alkaline conditions. The effect of these complexes on radionuclide solubility in the near-field and alkaline-disturbed zone is shown. The constants were measured by the ion-exchange (Schubert) method [1] with the exception of U(VI) at pH 13.3, for which the solubility product method [2] was used. At pH7 each complex was of the form M1ISA1, with log β values suggestive of salt formation. At high pH, log β values were between 13 and 20. The number of hydroxide ions involved in the complexation reactions was determined using Bjerrum plots, conductometric titrations and spectrophotometric methods [1]. The constants have enabled speciation calculations to be performed showing the effect of ISA on the metal's solubility. Solubility is predicted to increase in the presence of ISA from pH 9 to 13.5, suggesting that it may have an impact on radionuclide behaviour. The largest solubility increases are for Cd and Co, the smallest for U(VI).
© by Oldenbourg Wissenschaftsverlag, München
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- Preface - Special Issue: NUCAR 2005
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- Extraction of neptunium(IV) by a mixture of 3-phenyl-4-acetyl-5-isoxazolone and tri-n-octyl phosphine oxide
- Third phase formation in the extraction of Th(NO3)4 by tri-2-methyl butyl phosphate from nitric acid media
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- Transport of uranium from nitric acid solution by non-dispersive solvent extraction using a hollow fibre contactor
- Fixation of some major fission products in NaZr2P3O12 ceramic employing microwave heating
- Synthesis, characterization and structural refinement of polycrystalline uranium substituted zirconolite CaZr0.9U0.1Ti2O7
- Effect of glass composition on diffusion of cesium in borosilicate glass
- Studies on diffusional mobility and selectivity of I− ion in plasticized anion-exchange membrane using radiotracer
- BEHSA grafted polymer for selective extraction of U(VI), Th(IV) and La(III) from acidic matrices and environmental samples – a green process
- Studies on the dissolution behaviour of ThO2 and (U,Th)O2 by a solid state reaction method
- Studies on some divalent metal α-isosaccharinic acid complexes
- Effect of humic acid on cesium sorption on silica colloids
- Preparation and preliminary biological evaluation of a 177Lu labeled nitroimidazole derivative for possible use in targeted tumor therapy
Articles in the same Issue
- Preface - Special Issue: NUCAR 2005
- Incomplete fusion mechanism in 16O + 93Nb reaction at 6 MeV/nucleon: Recoil range measurements
- Extraction of actinides using N, N, N′, N′-tetraoctyl diglycolamide (TODGA): a thermodynamic study
- Extraction of neptunium(IV) by a mixture of 3-phenyl-4-acetyl-5-isoxazolone and tri-n-octyl phosphine oxide
- Third phase formation in the extraction of Th(NO3)4 by tri-2-methyl butyl phosphate from nitric acid media
- Solvent extraction behaviour of some fission product elements with N,N-dihexyl octanamide and tri-n-butyl phosphate under simulated PUREX process conditions
- Transport of uranium from nitric acid solution by non-dispersive solvent extraction using a hollow fibre contactor
- Fixation of some major fission products in NaZr2P3O12 ceramic employing microwave heating
- Synthesis, characterization and structural refinement of polycrystalline uranium substituted zirconolite CaZr0.9U0.1Ti2O7
- Effect of glass composition on diffusion of cesium in borosilicate glass
- Studies on diffusional mobility and selectivity of I− ion in plasticized anion-exchange membrane using radiotracer
- BEHSA grafted polymer for selective extraction of U(VI), Th(IV) and La(III) from acidic matrices and environmental samples – a green process
- Studies on the dissolution behaviour of ThO2 and (U,Th)O2 by a solid state reaction method
- Studies on some divalent metal α-isosaccharinic acid complexes
- Effect of humic acid on cesium sorption on silica colloids
- Preparation and preliminary biological evaluation of a 177Lu labeled nitroimidazole derivative for possible use in targeted tumor therapy
