Thorium sorption onto magnetite and ferrihydrite in acidic conditions

Rojo, Isabel; Seco, F.; Rovira, Miquel; Giménez, Javier; Cervantes, G. Garcia; Martí, Vicenç; Pablo, Joan de

doi:10.1016/j.jnucmat.2008.12.014

Cited by 44 publications

(22 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…None of the 11 different adsorbents presented higher adsorption capacities than natural and modified clays for Th(IV) uptake, indicating that these adsorbents could be successfully employed for removal of this metallic specie from aqueous solution. 5,8,[27][28][29][30][31][32][33] As observed, the present series of results obtained from natural and modified Amazon clays present the same order of magnitude as those obtained with the magnetite, 28 ferridrite 28 and perlite. 29 From calorimetric titration data, the net thermal effects resulted in corresponding well-behaved isotherms that were fitted to the Sips model, as shown in Figures 6a and 6b.…”

Section: Adsorption and Thermodynamic Studiessupporting

confidence: 78%

Adsorption of thorium(IV) on chemically modified Amazon clays

Guerra¹,

Viana²,

Airoldi³

2009

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Amostras de caulinita e esmectita oriundas da região Amazônica, Brasil, foram modificadas com 2-mercaptobenzimidazol (MBI) usando rotas homogênea e heterogênea. As amostras de argilas modificadas (K HOM, S HOM , K HET e S HET ) foram caracterizadas por análise textural, MEV e espectroscopia 13 C NMR. As argilas modificadas quimicamente apresentaram modificações em suas propriedades físico-químicas incluindo: área específica 48,0 (S) para 869,8 m 2 g -1 (S HET ). A habilidade destes materiais para remover tório(IV) em soluções aquosas foi investigada por um série de isotermas de adsorção ajustadas pela equação de Sips em temperatura ambiente e pH 2,0. O número máximo de mols adsorvidos foi determinado em 8,29,8,86,9,57 e 9,89 10 -1 mmol g -1 para K HOM , K HET , S HOM e S HET , respectivamente. Os efeitos energéticos causados pela adsorção do cation tório(IV) foram determinados através de metodologia calorimétrica.Kaolinite and smectite clay samples from the Amazon region, Brazil, were modified with 2-mercaptobenzimidazole (MBI) using homogeneous and heterogeneous routes. The modified clay samples (K HOM , S HOM , K HET and S HET ) were characterized by textural analysis, SEM and 13 C NMR spectroscopy. The chemically modified clay samples showed modifications of their physicalchemical properties including: specific area 48.0 (S) to 869.8 m 2 g -1 (S HET ). The ability of these materials to remove thorium(IV) from aqueous solution was followed by a series of adsorption isotherms adjusted to a Sips equation at room temperature, and pH 2.0. The maximum number of moles adsorbed was determined to be 8. 29, 8.86, 9.57 and 9.89 10 -1 mmol g -1 for K HOM , K HET , S HOM and S HET , respectively. The energetic effects (∆ int H, ∆ int G and ∆ int S) caused by thorium(IV) cation adsorption were determined through calorimetry.

show abstract

Section: Adsorption and Thermodynamic Studiessupporting

confidence: 78%

Adsorption of thorium(IV) on chemically modified Amazon clays

Guerra¹,

Viana²,

Airoldi³

2009

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…Thorium binding was optimised using the data of Rojo et al (2009), who presented three pH adsorption envelopes for Th on HFO in the pH range 1.5-4.5. Three concentrations of thorium -0.95µM, 1.1µM and 1.7µM -were used, and an HFO concentrations HFO of 10 g dm -3 .…”

Section: Optimisation Of Thorium Bindingmentioning

confidence: 99%

Assessment of co-contaminant effects on uranium and thorium speciation in freshwater using geochemical modelling

Lofts

Février

Horemans

et al. 2015

Journal of Environmental Radioactivity

View full text Add to dashboard Cite

“…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

View full text Add to dashboard Cite

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.

show abstract

Thorium sorption onto magnetite and ferrihydrite in acidic conditions

Cited by 44 publications

References 30 publications

Adsorption of thorium(IV) on chemically modified Amazon clays

Adsorption of thorium(IV) on chemically modified Amazon clays

Assessment of co-contaminant effects on uranium and thorium speciation in freshwater using geochemical modelling

Sorption of tetravalent thorium on muscovite

Contact Info

Product

Resources

About