Spectroscopic Study of Cm(III) Sorption onto γ-Alumina

Stumpf, Th.; Rabung, Thomas; Klenze, R.; Geckeis, Horst; Kim, J.I.

doi:10.1006/jcis.2001.7490

Cited by 73 publications

(69 citation statements)

References 16 publications

(35 reference statements)

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“…4A and B, the I 593 /I 617 peak ratio clearly depends on the pH of the suspension and decreases with increasing pH. This behaviour is in good agreement with the results of many studies (Stumpf et al, 2001;Stumpf et al, 2002a,b;Kowal-Fouchard et al, 2004;Rabung et al, 2005). We attribute this effect to a pH-related change in the atomic environment of the sorbed Eu(III), as suggested by the fluorescence time measurements.…”

Section: Trlfs Spectrum Of Sorbed Eu(iii)supporting

confidence: 89%

“…Previous studies on lanthanide/clay systems using similar experimental protocols (Stumpf et al, 2001(Stumpf et al, , 2002aCoppin et al, 2002;Kowal-Fouchard et al, 2004;Rabung et al, 2005) have shown that Ln(III)-bearing phases do not precipitate during sorption experiments conducted at 25°C. This was suggested by the consistence of the sorption data and further supported by TRLFS data (Stumpf et al, 2002a,b;Kowal-Fouchard et al, 2004).…”

Section: Trlfs Spectrum Of Sorbed Eu(iii)mentioning

confidence: 94%

“…As described in the experimental section, we performed some experiments at 25 and 80°C to study the sorption of Eu(III) onto simple oxides: alumina (c-Al 2 O 3 ), gibbsite (a-Al(OH) 3 ), quartz (SiO 2 ) and solid amorphous silica. The runs were conducted at 25 and 80°C at neutral pH (7.0 at 25°C; 6.3 at 80°C), where there is known to be almost complete sorption of trivalent metals (Kosmulski, 1997;Rabung et al, 2000;Wang et al, 2000;Stumpf et al, 2001;Kowal-Fouchard et al, 2004). Under such pH conditions, sorption is mainly attributed to surface complexation on aluminol sites (for alumina and gibbsite) or silanol sites (for quartz and amorphous silica).…”

Section: Trlfs Spectrum Of Sorbed Eu(iii)mentioning

confidence: 99%

“…Thus, it can even be applied at high temperature, since previous spectroscopic data are only available at room temperature: e.g. Stumpf et al, 2001; for Cm(III) onto kaolinite and montmorillonite; Chisholm-Brause et al, 2004 andKowal-Fouchard et al, 2004; for Eu(III) and uranyl onto montmorillonite.…”

Section: Introductionmentioning

confidence: 98%

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Europium retention onto clay minerals from 25 to 150°C: Experimental measurements, spectroscopic features and sorption modelling

Tertre

Berger

Simoni

et al. 2006

Geochimica et Cosmochimica Acta

176

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The sorption of Eu(III) onto kaolinite and montmorillonite was investigated up to 150°C. The clays were purified samples, saturated with Na in the case of montmorillonite. Batch experiments were conducted at 25, 40, 80 and 150°C in 0.5 M NaClO 4 solutions to measure the distribution coefficients (Kd) of Eu as a trace element (<10 À6 mol/L) between the solution and kaolinite. For the Na-montmorillonite, we used Kd results from a previous study [Tertre, E., Berger, G., Castet, S., Loubet, M., Giffaut, E., 2005. Experimental study of adsorption of Ni 2+ , Cs + and Ln 3+ onto Na-montmorillonite up to 150°C. Geochim. Cosmochim. Acta 69, 4937-4948] obtained under exactly the same conditions. The number and nature of the Eu species sorbed onto both clay minerals were investigated by time resolved laser fluorescence spectroscopy (TRLFS) in specific experiments in the same temperature range. We identified a unique inner-sphere complex linked to the aluminol sites in both clays, assumed to be @AlOEu 2+ at the edge of the particles, and a second exchangeable outersphere complex for montmorillonite, probably in an interlayer position. The Kd values were used to adjust the parameters of a surface complexation model (DLM: diffuse layer model) from 25 to 150°C. The number of Eu complexes and the stoichiometry of reactions were constrained by TRLFS. The acidity constants of the amphoteric aluminol sites were taken from another study [Tertre, E., Castet, S., Berger, G., Loubet, M., Giffaut, E. Acid/base surface chemistry of kaolinite and Na-montmorillonite at 25 and 60°C: experimental study and modelling. Geochim. Cosmochim. Acta, in press], which integrates the influence of the negative structural charge of clays on the acid/base properties of edge sites as a function of temperature and ionic strength. The results of the modelling show that the observed shift of the sorption edge towards low pH with increasing temperature results solely from the contribution of the @AlOEu 2+ edge complexes. Finally, we successfully tested the performance of our model by confronting the predictions with experimental Kd data. We used our own data obtained at lower ionic strength (previous study) or higher suspension density and higher starting concentration (TRLFS runs, this study), as well as published data from other experimental studies [Bradbury, M.H., Baeyens, B., 2002. Sorption of Eu on Na and Ca-montmorillonite: experimental investigations and modeling with cation exchange and surface complexation. Geochim. Cosmochim. Acta 66, 2325-2334; Kowal-Fouchard, A., 2002. Etude des mécanismes de rétention des ions U(IV) et Eu(III) sur les argiles: influence des silicates. Ph.D. Thesis, Université Paris Sud, France, 330p].

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Section: Trlfs Spectrum Of Sorbed Eu(iii)supporting

confidence: 89%

Section: Trlfs Spectrum Of Sorbed Eu(iii)mentioning

confidence: 94%

Section: Trlfs Spectrum Of Sorbed Eu(iii)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Europium retention onto clay minerals from 25 to 150°C: Experimental measurements, spectroscopic features and sorption modelling

Tertre

Berger

Simoni

et al. 2006

Geochimica et Cosmochimica Acta

176

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“…Although the incorporation of radionuclides into the bulk structure represents another very important mechanism for their retardation, very little is known about these processes. Only a very few systematic studies for investigating the incorporation mechanisms in the trace concentration range have been performed (7)(8)(9). As a consequence these processes are in general neglected in the performance assessment of a nuclear waste repository.…”

Section: Introductionmentioning

confidence: 99%

A Time-Resolved Laser Fluorescence Spectroscopy (TRLFS) Study of the Interaction of Trivalent Actinides (Cm(III)) with Calcite

Stumpf

Fanghänel

2002

Journal of Colloid and Interface Science

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Americium and Curium: Radionuclides

Runde

2005

Encyclopedia of Inorganic Chemistry

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Following the element plutonium, americium and curium are the sixth and seventh elements in the actinide series. The primordial americium and curium isotopes that formed during the creation of the solar system billions of years ago have decayed away. Today, residual amounts of americium and curium isotopes present in nature are anthropogenic, originating from human activities such as nuclear weapons testing or nuclear energy generation. All americium and curium isotopes are highly radioactive and pose extreme health hazards to humans, especially when ingested or inhaled. Complexation reactions with environmentally relevant ligands, separation chemistry, the mechanistic studies of the processes that Am(III) and Cm(III) undergo at the solid–liquid interface in nature, and innovative process applications have been the focus of many studies during recent decades. In general, the trivalent oxidation state of americium and curium is the most stable under environmental conditions. As hard cations, the Am 3+ and Cm 3+ ions form strong complexes with hard donor ligands and adsorb readily on surfaces. In the absence of carbonate, hydrolysis leads to sparingly soluble Am(III) and Cm(III) hydroxide complexes. Americium and curium are commonly used in home smoke detectors and for oil‐well logging ( 241 Am), and as radioisotope thermoelectric generators ( 244 Cm).

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Spectroscopic Study of Cm(III) Sorption onto γ-Alumina

Cited by 73 publications

References 16 publications

Europium retention onto clay minerals from 25 to 150°C: Experimental measurements, spectroscopic features and sorption modelling

Europium retention onto clay minerals from 25 to 150°C: Experimental measurements, spectroscopic features and sorption modelling

A Time-Resolved Laser Fluorescence Spectroscopy (TRLFS) Study of the Interaction of Trivalent Actinides (Cm(III)) with Calcite

Americium and Curium: Radionuclides

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