A comparative batch sorption and time-resolved laser fluorescence spectroscopy study on the sorption of Eu(III) and Cm(III) on synthetic and natural kaolinite
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N. Huittinen
Abstract
Eu(III) and Cm(III) sorption onto synthetic and natural kaolinite (St. Austell, UK) were studied by batch sorption experiments and time-resolved laser fluorescence spectroscopy (TRLFS). All investigations were performed under argon atmosphere (O2<1 ppm). 0.1 M NaClO4 and 0.25 g/L kaolinite were used as electrolyte and solid concentrations, respectively, throughout the study. Batch sorption experiments were performed with Eu(III), a homologue to trivalent actinides at three different metal ion concentrations between 6.6×10−8 and 6.6×10−6 M. pH-dependent sorption was found to be congruent for the two lowest Eu(III) concentrations (6.6×10−8 and 6.6×10−7 M) while a shift of the sorption distribution coefficient, Kd, to higher pH values was observed for the highest metal ion concentration (6.6×10−6 M). Furthermore, the natural kaolinite showed higher uptake of Eu(III) for the lowest metal ion concentration at pH<5 as compared to the synthetic product. This difference is believed to arise from a higher amount of Eu(III) being sorbed as outer-sphere species on the natural kaolinite due to its negative surface charge being higher than that of the synthetic mineral. The spectroscopic investigations were performed with 2×10−7 M Cm(III) as a luminescent probe. Four single component spectra could be extracted from the recorded emission spectra for both the synthetic and the natural kaolinite, with peak positions in average at 598.8, 602.7, 607.4 and 611.0 nm. The three first emission peaks appearing between pH 5 and 13 were assigned to three inner-sphere Cm-complexes. The fourth emission peak appearing in the alkaline pH range (>9) is assumed to be a result of Cm(III) incorporation by a surface precipitate of hitherto unknown composition.
© by Oldenbourg Wissenschaftsverlag, University of Helsinki, Germany
Articles in the same Issue
- Preface
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- Solubility of triuranyl diphosphate tetrahydrate (TDT) and Na autunite at 23 and 50 °C
- Effect of reduction on the stability of Pu(VI) hydrolysis species
- Retention and redox behaviour of uranium(VI) by siderite (FeCO3)
- Neptunium(V) complexation by natural pyoverdins and related model compounds
- Complexation of Nd(III) with tetraborate ion and its effect on actinide(III) solubility in WIPP brine
- Complexation of Tc(IV) with acetate at varying ionic strengths
- Uranyl photochemistry: decarboxylation of gluconic acid
- Influence of Boom Clay organic matter on the adsorption of Eu3+ by illite – geochemical modelling using the component additivity approach
- The role of green rust in the migration of radionuclides: An overview of processes that can control mobility of radioactive elements in the environment using as examples Np, Se and Cr
- A comparative batch sorption and time-resolved laser fluorescence spectroscopy study on the sorption of Eu(III) and Cm(III) on synthetic and natural kaolinite
- U(VI) sorption on granite: prediction and experiments
- Quantum chemical study of inner-sphere complexes of trivalent lanthanide and actinide ions on the corundum (0001) surface
- Quantum chemical modeling of uranyl adsorption on mineral surfaces
- Interaction of PuO2 thin films with water
- Molecular interactions of plutonium(VI) with synthetic manganese-substituted goethite
- Chlorine speciation in nuclear graphite: consequences on temperature release and on leaching
- Chemical status of U(VI) in cemented waste forms under saline conditions
- Influence of iron redox transformations on plutonium sorption to sediments
- Modelling of a large-scale in-situ migration experiment with 14C-labelled natural organic matter in Boom Clay
- Sorption and diffusion of Eu in sedimentary rock in the presence of humic substance
- Diffusion and sorption of neptunium(V) in compacted montmorillonite: effects of carbonate and salinity
- Uranium(VI) diffusion in low-permeability subsurface materials
- Distribution of Cs and Am in the solution-bentonite colloids-granite ternary system: effect of addition order and sorption reversibility
- Mechanisms of plutonium sorption to mineral oxide surfaces: new insights with implications for colloid-enhanced migration
- Understanding uranium behaviour at the Askola uranium mineralization
Articles in the same Issue
- Preface
- Solubility of tetravalent actinides in alkaline CaCl2 solutions and formation of Ca4[An(OH)8]4+ complexes: A study of Np(IV) and Pu(IV) under reducing conditions and the systematic trend in the An(IV) series
- Solubility of triuranyl diphosphate tetrahydrate (TDT) and Na autunite at 23 and 50 °C
- Effect of reduction on the stability of Pu(VI) hydrolysis species
- Retention and redox behaviour of uranium(VI) by siderite (FeCO3)
- Neptunium(V) complexation by natural pyoverdins and related model compounds
- Complexation of Nd(III) with tetraborate ion and its effect on actinide(III) solubility in WIPP brine
- Complexation of Tc(IV) with acetate at varying ionic strengths
- Uranyl photochemistry: decarboxylation of gluconic acid
- Influence of Boom Clay organic matter on the adsorption of Eu3+ by illite – geochemical modelling using the component additivity approach
- The role of green rust in the migration of radionuclides: An overview of processes that can control mobility of radioactive elements in the environment using as examples Np, Se and Cr
- A comparative batch sorption and time-resolved laser fluorescence spectroscopy study on the sorption of Eu(III) and Cm(III) on synthetic and natural kaolinite
- U(VI) sorption on granite: prediction and experiments
- Quantum chemical study of inner-sphere complexes of trivalent lanthanide and actinide ions on the corundum (0001) surface
- Quantum chemical modeling of uranyl adsorption on mineral surfaces
- Interaction of PuO2 thin films with water
- Molecular interactions of plutonium(VI) with synthetic manganese-substituted goethite
- Chlorine speciation in nuclear graphite: consequences on temperature release and on leaching
- Chemical status of U(VI) in cemented waste forms under saline conditions
- Influence of iron redox transformations on plutonium sorption to sediments
- Modelling of a large-scale in-situ migration experiment with 14C-labelled natural organic matter in Boom Clay
- Sorption and diffusion of Eu in sedimentary rock in the presence of humic substance
- Diffusion and sorption of neptunium(V) in compacted montmorillonite: effects of carbonate and salinity
- Uranium(VI) diffusion in low-permeability subsurface materials
- Distribution of Cs and Am in the solution-bentonite colloids-granite ternary system: effect of addition order and sorption reversibility
- Mechanisms of plutonium sorption to mineral oxide surfaces: new insights with implications for colloid-enhanced migration
- Understanding uranium behaviour at the Askola uranium mineralization
