Influence of Boom Clay organic matter on the adsorption of Eu3+ by illite – geochemical modelling using the component additivity approach
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C. Bruggeman
Abstract
The solid–liquid distribution of europium (Eu) between an adsorptive surface and a solution phase containing a competitive colloid is the result of a delicate balance between several individual chemical reactions. In this study, adsorption isotherms of Eu in presence of dissolved Boom Clay natural organic matter were experimentally determined under conditions relevant for a geological repository (trace Eu concentrations, anoxic conditions, ∼0.014 mol l−1 NaHCO3 background electrolyte). It was found that both the concentration and size distribution (or operational cut-off used to discriminate between “mobile” and “immobile” colloids) of natural organic matter has a strong influence on the observed solid–liquid distribution.
The experimental data were subsequently modelled using a component additive approach with two well-established sorption/interaction models: the 2 SPNE SC/CE model for describing Eu adsorption on illite, and Humic Ion-Binding Model VI for describing Eu complexation to natural organic matter. Model parameters were gathered from dedicated measurements in batch systems containing only Eu and the interacting phase under study, under similar conditions as in the ternary isotherm experiments. Mutual interactions between illite and natural organic matter were studied and quantified. Under the experimental conditions of this study, it was found that these interactions were only of minor importance.
The two models were subsequently combined to blind predict the Eu solid–liquid distribution in the ternary batch experiments. Within an error margin of 0.5logߙKd units, the additivity approach succeeded well in predicting Eu uptake in all experimental systems studied. A sensitivity analysis was performed to select the most important model parameters influencing the Eu uptake, and the robustness of the model. This study has shown that the component additivity approach for describing and predicting uptake of trivalent lanthanides/actinides under Boom Clay conditions, is promising, and may help in unraveling the complex behaviour of these radionuclides witnessed in migration experiments.
© by Oldenbourg Wissenschaftsverlag, Mol, Germany
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- Preface
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- Solubility of triuranyl diphosphate tetrahydrate (TDT) and Na autunite at 23 and 50 °C
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- 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
