Comparison of complexed species of Eu in alumina-bound and free polyacrylic acid: A spectroscopic study

Montavon, G.; Hennig, Christoph; Janvier, Pascal; Grambow, Bernd

doi:10.1016/j.jcis.2006.04.053

Cited by 20 publications

(17 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar species is therefore expected in EuPAA and EuPAA ads complexes. All these conclusions are in agreement with those reported in a previous study performed with Eu as a function of r by laser-induced fluorescence spectroscopy using 7 F 0 → 5 D 0 excitation spectra [16].…”

Section: Effect Of Metal Ion Loadingsupporting

confidence: 93%

See 1 more Smart Citation

Modeling the complexation properties of mineral-bound organic polyelectrolyte: An attempt at comprehension using the model system alumina/polyacrylic acid/M (M = Eu, Cm, Gd)

Montavon

Markai

Ribet

et al. 2007

Journal of Colloid and Interface Science

Self Cite

View full text Add to dashboard Cite

This paper contributes to the comprehension of kinetic and equilibrium phenomena governing metal ion sorption on organic-matter-coated mineral particles. Sorption and desorption experiments were carried out with Eu ion and polyacrylic acid (PAA)-coated alumina colloids at pH 5 in 0.1 M NaClO(4) as a function of the metal ion loading. Under these conditions, M interaction with the solid is governed by sorbed PAA (PAA(ads)). The results were compared with spectroscopic data obtained by time-resolved laser-induced fluorescence spectroscopy (TRLFS) with Cm and Gd. The interaction between M and PAA(ads) was characterized by a kinetically controlled process: after rapid metal adsorption within less than 1 min, the speciation of complexed M changed at the particle surface till an equilibrium was reached after about 4 days. At equilibrium, one part of complexed M was shown to be not exchangeable. This process was strongly dependent on the ligand-to-metal ratio. Two models were tested to explain the data. In model 1, the kinetically controlled process was described through successive kinetically controlled reactions that follow the rapid metal ion adsorption. In model 2, the organic layer was considered as a porous medium: the kinetic process was explained by the diffusion of M from the surface into the organic layer. Model 1 allowed a very good description of equilibrium and kinetic experimental data. Model 2 could describe the data at equilibrium but could not explain the kinetic data accurately. In spite of this disagreement, model 2 appeared more realistic considering the results of the TRLFS measurements.

show abstract

Section: Effect Of Metal Ion Loadingsupporting

confidence: 93%

“…Data are already available for Eu [16]. In this study, the previous data were completed with Cm, which has the advantage of being more sensitive than Eu.…”

Section: With [M] P Being the Concentration Of Complexed M Andmentioning

confidence: 99%

Modeling the complexation properties of mineral-bound organic polyelectrolyte: An attempt at comprehension using the model system alumina/polyacrylic acid/M (M = Eu, Cm, Gd)

Montavon

Markai

Ribet

et al. 2007

Journal of Colloid and Interface Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…Fan et al [28] studied Eu(III) sorption onto attapulgite in different KNO 3 solutions, and found that the sorption was dependent on ionic strength at pH \5.5 and independent of pH at pH[5.5. Similar sorption behavior were also found for Eu(III) interaction with other kinds of materials such as carbon nanotube/iron oxide magnetic composites [33], graphene oxides [34,35], montmorillonite [36] and alumina oxides [37][38][39][40][41].…”

Section: Effect Of Ionic Strength and Phsupporting

confidence: 74%

Sorption and desorption properties of Eu(III) on attapulgite

Chen

2015

J Radioanal Nucl Chem

View full text Add to dashboard Cite

The sorption-desorption of Eu(III) on attapulgite was studied using batch technique. The sorption of Eu(III) on attapulgite was strongly dependent on pH and ionic strength at low pH, and independent of ionic strength at high pH. The interaction was dominated by outer-sphere surface complexation/ion exchange at low pH, and by inner-sphere surface complexation at high pH. The irreversible sorption-desorption curves also suggested the formation of strong surface complexes. The high sorption capacity of attapulgite suggested that the attapulgite is a suitable material for the efficient elimination of Eu(III) from aqueous solutions in nuclear wastewater management.

show abstract

“…An illustration of both coordination modes is given in figure S3, for the case of the Yb-actetate complex. Indeed, lanthanides or actinides\O bond distances in the case of COO bi are generally longer than for COO mono as shown for Eu-polyacrylic acid (Montavon et al, 2006) or as discussed for U(VI) (Schmeide et al, 2003;and references therein). This is particularly well illustrated in the structure of Yb-formate determined by XRD (Furmanova et al, 1983), where formate coordinated to Yb in both modes.…”

Section: Exafs Analysis Of the Reference Yb-ligand Complexesmentioning

confidence: 77%

Effect of loading on the nature of the REE–humate complexes as determined by Yb3+ and Sm3+ LIII-edge EXAFS analysis

et al. 2015

View full text Add to dashboard Cite

International audienceHumic substances are major natural complexing agents that strongly influence the cycling of metal cations in the environment. The metal to humic acid (HA) concentration ratio (metal loading) can significantly impact the overall HA complexation properties in natural soils and waters. At low metal loading, cations bind to strong multi-carboxylate or -phenolate sites of HA. In addition, these strong sites might contain soft Lewis bases such as N or S, the contribution of which is still a matter of debate. Based on the possible ability of Rare Earth Elements (REE) to trace HA binding properties, the present study aimed at evaluating the influence of REE-loading on the HA binding mechanisms of two hard Lewis acids, Sm3+ and Yb3+. Extended X-ray Absorption Fine Structure (EXAFS) at the Sm and Yb LIII edge was used to analyze the local coordination of these intermediate and heavy REE ions, respectively, in a low and a high REE-loading HA sample. Data were interpreted by comparison with EXAFS data for a series of aqueous REE complexes with iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA) and a carboxylic-grafted resin. In all these samples, both a Yb–O (~ 2.31 Å) and a Yb–N (~ 2.50 Å) backscattering path could be identified in the first coordination shell of Yb. At low REE loading, the first coordination shell around the Yb bond to HA is described by a single Yb–O backscattering path, i.e. the presence of N could not be evidenced. By contrast, the carboxylic-grafted resin exhibits both a short (2.31 Å) and a long Yb–O average distance (2.44 Å), suggesting the coordination of carboxylate is bidentate. The Fourier transform of the high loading HA samples exhibits a broad first shell peak possibly described by two Yb–O distances (2.29 and 2.43 Å) suggesting two coordination modes of the carboxylic groups. Different Yb–HA complex structures can therefore be observed at different metal loadings. Unfortunately, the Sm EXAFS spectra could only be recorded up to k = 10 Å−1. There was no evidence of either a clear difference between the metal loadings or with Yb–HA complex structures. A comparison between the EXAFS results, PHREEQC-Model VI simulations, and the pattern of the REE complexation constants with simple organic ligands (REE:ligand 1:1 and 1:2 complexes) provides evidence that, at high loading, REE are bound to HA through bi-ligand complexes without any chelation effect in which REE may potentially act as a cation bridge between two organic molecules. At low loading, the fact that N could not be detected in the Yb first shell suggests that, at low loading, Yb binds to O-containing groups of HA rather than N-containing groups. This may call into question the definition of HA strong sites for REE binding such as soft Lewis base-containing sites

show abstract

Comparison of complexed species of Eu in alumina-bound and free polyacrylic acid: A spectroscopic study

Cited by 20 publications

References 30 publications

Modeling the complexation properties of mineral-bound organic polyelectrolyte: An attempt at comprehension using the model system alumina/polyacrylic acid/M (M = Eu, Cm, Gd)

Modeling the complexation properties of mineral-bound organic polyelectrolyte: An attempt at comprehension using the model system alumina/polyacrylic acid/M (M = Eu, Cm, Gd)

Sorption and desorption properties of Eu(III) on attapulgite

Effect of loading on the nature of the REE–humate complexes as determined by Yb3+ and Sm3+ LIII-edge EXAFS analysis

Contact Info

Product

Resources

About