Synthesis and characterization of an analogue of heulandite: Sorption applications for thorium(IV), europium(III), samarium(II) and iron(III) recovery from aqueous waste

Sharma, Pankaj; Singh, Gurcharan; Tomar, Radha

doi:10.1016/j.jcis.2008.12.074

Cited by 75 publications

(27 citation statements)

References 60 publications

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“…Sorption of Th(IV) has been extensively studied on minerals and materials associated with host rock formations (Landa et al, 1995;Ö sthols, 1995;Ö sthols et al, 1997;Li and Tao, 2002;Zhang et al, 2006) and the geotechnical and technical barrier systems (Jakobsson, 1999;Guo et al, 2005;Reiller et al, 2005;Sheng et al, 2008;Rojo et al, 2009;Sharma et al, 2009;Talip et al, 2009;Qian et al, 2010). The majority of these studies focused on quantifying thorium adsorption through the amount of Th(IV) removed from the solution, as determined by radiological or spectrophotometric methods, to derive a distribution coefficient K d .…”

Section: Thorium Sorptionmentioning

confidence: 99%

Sorption of tetravalent thorium on muscovite

Schmidt

Lee

Wilson

et al. 2012

Geochimica et Cosmochimica Acta

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Adsorption of tetravalent thorium to the (0 0 1) basal surface of the phyllosilicate muscovite from an aqueous solution (1 Â 10 À4 mol/L Th(IV) in 1 Â 10 À1 mol/L NaCl, pH = 3.2) was studied by crystal truncation rod (CTR) and resonant anomalous X-ray reflectivity (RAXR) measurements. Th uptake to the muscovite surface from solutions with total Th concentrations [Th] tot = 1 Â 10 À6 -4.88 Â 10 À3 mol/L and 1 Â 10 À1 mol/L NaCl, pH = 3.2 was quantified by alpha-spectrometry. The uptake measurements showed that Th adsorption to the muscovite surface follows a Langmuir isotherm with an apparent adsorption constant K app = 2 Â 10 4 L/mol up to [Th] tot = 1.02 Â 10 À3 mol/L. The CTR and RAXR results identified one dominant Th species with a very broad distribution centered $10 Å above the surface, in agreement with strongly hydrated extended outer sphere sorption. The findings indicate that the large energy of hydration (DG hyd = À5815 kJ/mol (Marcus, 1991)) for the small and highly-charged Th 4+ cation is a controlling parameter in its surface speciation. The surface occupancy (0.4 Th per unit cell area, A UC ) measured by RAXR exceeds the expected level for surface charge compensation by tetravalent Th (0.25 Th/A UC ). However, the radiometric uptake measurements show smaller occupancies (0.21 Th/A UC ) after rinsing by deionized water, indicating a partial removability of sorbed thorium. Thorium oligomerization was observed at total Th concentrations [Th] tot P 2.0 Â 10 À3 mol/L in presence of the surface, although solubility studies suggest that Th is soluble under these solution conditions.

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Section: Thorium Sorptionmentioning

confidence: 99%

Sorption of tetravalent thorium on muscovite

Schmidt

Lee

Wilson

et al. 2012

Geochimica et Cosmochimica Acta

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“…There is a wide range of studies aiming to quantify the sorption of Th on various natural and synthetic minerals (Landa et al, 1995;Jakobsson, 1999;Li and Tao, 2002;Guo et al, 2005;Sharma et al, 2006Sharma et al, , 2009Zhang et al, 2006;Sheng et al, 2008;Rojo et al, 2009;Talip et al, 2009). Several studies have attempted to gain a more mechanistic understanding through the use of advanced spectroscopic techniques (Ö sthols, 1995; Ö sthols et al, 1997), or surface complexation modeling (Reiller et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

“…However, little attention is usually given to the choice of background electrolyte. Many studies are performed in NO 3 À media (Li and Tao, 2002;Guo et al, 2005;Reiller et al, 2005;Sharma et al, 2006Sharma et al, , 2009Zhang et al, 2006;Sheng et al, 2008;Talip et al, 2009), presumably due to its relevance in chemical-separations processes and its ubiquitous presence in groundwater. Studies in ClO 4 À media are also commonly found (Ö sthols, 1995;Ö sthols et al, 1997;Jakobsson, 1999;Reiller et al, 2005;Rojo et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Effects of the background electrolyte on Th(IV) sorption to muscovite mica

Schmidt

Hellebrandt

Knope

et al. 2015

Geochimica et Cosmochimica Acta

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The adsorption of tetravalent thorium on the muscovite mica (0 0 1) basal plane was studied by X-ray crystal truncation rod (CTR) and resonant anomalous X-ray reflectivity (RAXR) measurements and alpha spectrometry in the presence of perchlorate background electrolytes LiClO 4 , NaClO 4 , and KClO 4 ([Th(IV)] = 0.1 mM, I = 0.1 M or 0.01 M, pH = 3.3 ± 0.3). RAXR data directly reveal a strong influence of the background electrolyte on the actinide sorption. No significant Th adsorption was observed in 0.1 M NaClO 4 , i.e., the Th coverage h(Th), the number of Th per unit cell area of the muscovite surface (A UC = 46.72 Å 2 ), was 60.01 Th/A UC , whereas limited uptake (h(Th) $ 0.04 Th/A UC ) was detected at a lower ionic strength (I = 0.01 M). These results are in stark contrast to the behavior of Th in 0.1 M NaCl which showed a coverage of 0.4 Th/A UC (Schmidt et al., 2012a). Th uptake was also influenced by the electrolyte cation. Weak adsorption was observed in 0.1 M KClO 4 (h(Th) $ 0.07 Th/A UC ) similar to the results in NaClO 4 at lower ionic strength. In contrast, strong adsorption was found in 0.1 M LiClO 4 , with h(Th) = 4.9 Th/A UC , a $10-fold increase compared with that previously reported in NaCl. These differences are confirmed independently by ex situ alpha spectrometry, which shows no measurable Th coverage in 0.1 M NaClO 4 background in contrast to a large coverage of 1.6 Th/A UC in 0.1 M LiClO 4 . Alpha spectrometry cannot be obtained in situ, but sample preparation requires several washing steps that may affect Th(IV) sorption, RAXR, however, is considered to reflect the in situ sorption structure. The CTR/RAXR analyses of Th-LiClO 4 show the sorption structure consisting of Th species that are broadly distributed, centered at heights of 4.1 Å and 29 Å distance from the interface. Neither the very large distribution height of the second species nor the high coverage can be explained with (hydrated) ionic adsorption, suggesting that the enhanced uptake is presumably due to the formation and sorption of Th nanoparticles.

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“…On the other hand barium and europium are frequently used as natural homologues of Ra and trivalent actinides (e.g. Am, Cm) respectively [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Thermally modified molybdenum oxide as a potential sorbent for the removal of metal cations from aqueous solutions

Kapnisti

Noli

Arvanitidis

et al. 2015

J Radioanal Nucl Chem

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The effectiveness of a low cost sorbent produced by thermal modification of ammonium heptamolybdate (AHM) in adsorption of radionuclides and heavy metals was investigated. The product was characterized by XRD, SEM and Raman spectroscopy. Sorption experiments were performed in Pb, U, Cs, Ba and Eu solutions (pH 2.0-6.0). The obtained isotherms were simulated by Langmuir and Freundlich isotherms and kinetics data were used in order to evaluate the sorption mechanism. The results showed the high and selective efficiency of the AHM-derived MoO 3 especially in Pb and U removal whereas the desorption experiments revealed its environmental applicability under real conditions for the investigated metal cations.

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Synthesis and characterization of an analogue of heulandite: Sorption applications for thorium(IV), europium(III), samarium(II) and iron(III) recovery from aqueous waste

Cited by 75 publications

References 60 publications

Sorption of tetravalent thorium on muscovite

Sorption of tetravalent thorium on muscovite

Effects of the background electrolyte on Th(IV) sorption to muscovite mica

Thermally modified molybdenum oxide as a potential sorbent for the removal of metal cations from aqueous solutions

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