Assessment of synthetic zeolite Na A–X as sorbing barrier for strontium in a radioactive disposal facility

Rahman, Rehab O. Abdel; Ibrahim, H.A.; Hanafy, M.; Monem, N.M. Abdel

doi:10.1016/j.cej.2009.10.057

Cited by 96 publications

(26 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…on clay at equilibrium (mg/g) and k 2 is the constant rate of pseudo-second order adsorption (g/ mg min). The kinetic intra-particle model has been extensively used to describe sorption rates in various types of materials [24,[26][27][28]. In this case, uptake varies with t 1/2 rather than with the contact time, according to Eq.…”

Section: Kinetics Modelsmentioning

confidence: 99%

“…Pseudo-second order model [23][24][25] is derived on the basis of the sorption capacity of the solid and could be expressed by the linear Eq. 5:…”

Section: Kinetics Modelsmentioning

confidence: 99%

“…in the beginning and the end of the adsorption process, V is the solution volume used during batch experiments (14.00 mL) and m is the mass of clay used (0.050 g). The equilibrium parameter constant (R L ) used as an indicator to assess the extent of adsorption was calculated using the Langmuir constant [2,24,35,36] according with Eq. 10:…”

Section: Modeling Of the Isothermsmentioning

confidence: 99%

See 2 more Smart Citations

Influence of pH, concentration and ionic strength during batch and flow-through continuous stirred reactor experiments of Sr2+-adsorption onto montmorillonite

Guimarães¹,

Azenha²,

Rocha

et al. 2014

J Radioanal Nucl Chem

View full text Add to dashboard Cite

Sorption/desorption experiments in batch and continous flow-through stirred reactor under different experimental conditions were carried out using montmorillonite (\2 lm clay fractions). The Sr 2? amount desorbed at pH 4 is only half of the amount desorbed at pH 8, revealing that the retention of Sr 2? onto montmorillonite was enhanced at pH 4. The largest adsorption value was obtained at pH 8.0 ([KNO 3 ] = 10 -3 mol/L) with q m = 41.49 mg Sr 2? /g from the Langmuir isotherm. The gradient of concentration acted as an increasing driving force since the amount of Sr 2? adsorbed increased as increasing of Sr 2? concentration during the flow-through experiments.

show abstract

Section: Kinetics Modelsmentioning

confidence: 99%

“…Pseudo-second order model [23][24][25] is derived on the basis of the sorption capacity of the solid and could be expressed by the linear Eq. 5:…”

Section: Kinetics Modelsmentioning

confidence: 99%

Section: Modeling Of the Isothermsmentioning

confidence: 99%

See 1 more Smart Citation

Influence of pH, concentration and ionic strength during batch and flow-through continuous stirred reactor experiments of Sr2+-adsorption onto montmorillonite

Guimarães¹,

Azenha²,

Rocha

et al. 2014

J Radioanal Nucl Chem

View full text Add to dashboard Cite

show abstract

“…Moreover, inorganic wastes match well with classical waste confinement networks, such as vitrification or cement plants. In the case of inorganic sorbents for strontium-ion adsorption from aqueous solutions, naturally occurring materials, such as bentonite (clays) (Bochkarev and Pushkareva 2009;Bascetin and Atun 2010), zeolites (Rahman et al 2010;Boyd et al 1947), other nanoporous framework or hybrid materials (Li et al 2010), and hydrous metal oxides (Kirillov et al 2006) have been studied for metal separation applications. Another interesting class of inorganic sorbents proposed in the literature includes titanate and silicotitanates (Behrens et al 1998;DeFilippi et al 1997;Clearfield and Lehto 1988;Duff et al 2004;Masaki et al 2002;Graziano 1998), which could allow the adsorption of Sr 2+ from aqueous solution.…”

Section: Introductionmentioning

confidence: 99%

Effect of the synthesis temperature of sodium nonatitanate on batch kinetics of strontium-ion adsorption from aqueous solution

et al. 2011

View full text Add to dashboard Cite

Sodium titanate materials are promising inorganic ion exchangers for the adsorption of strontium from aqueous solutions. Sodium nonatitanate exhibits a layered structure consisting of titanate layers and exchangeable sodium ions between the layers. The materials used in this study include samples synthesized by a hydrothermal method at temperatures between 60°C and 200°C. Their structure, composition, and morphology were investigated with X-Ray diffraction measurements; thermogravimetric, compositional and surface area analyses, and scanning electron microscopy. The structure, composition, and morphology depended on the synthesis temperature. Batch kinetics experiments for the removal of strontium from aqueous solutions were performed, and the data were fitted by a pseudo-second-order reaction model and a diffusive model. The strontium extraction capacity also depended on the synthesis temperature and exhibited a maximum for samples synthesized at 100°C. The sorption process occurs in one or two diffusion-controlled steps that also depend on the synthesis temperature. These diffusion-limited steps are the boundary-layer diffusion and intra-particle diffusion in the case of pure nonatitanate synthesized at temperatures lower than 170°C, and only intra-particle diffusion in the case of nonatitanate synthesized at 200°C.

show abstract

“…Langmuir isotherm plot for the sorption of cesium on clay colloid at different L [ 1)(Rahman et al 2010). The ranges of R L values…”

mentioning

confidence: 99%

Sorption of Cesium on Clay Colloids: Kinetic and Thermodynamic Studies

Rani

Sasidhar

2012

Aquat Geochem

View full text Add to dashboard Cite

Sorption of radionuclides onto stable colloids can significantly enhance their transport in groundwater. Batch adsorption studies were performed to evaluate the influence of various experimental parameters like initial pH, contact time, temperature and concentration of Na ? and Ca 2? ions on the sorption of Cs on clay. The sorption process is dependent on pH of the solution with distribution coefficient (K d ) found to increase with increase in pH. The kinetic experiments were carried out at different temperatures, and the results have shown that the sorption process fits well into a pseudo-second-order mechanism with apparent activation energy of 45.7 kJ/mol. The rate constant was found to decrease with increase in temperature. The thermodynamic parameters such as DG 0 , DH 0 and DS 0 were calculated. The negative value of DH 0 indicates that the reaction is exothermic. The negative values obtained for DG 0 indicated that the sorption of cesium on clay was spontaneous at all studied concentrations. The distribution coefficient was found to decrease with increasing concentration of Na ? and Ca 2? ions. The cesium sorption data were fitted to Freundlich, Langmuir, Temkin and Dubinin-Radushkevich (D-R) isotherms. The values of Langmuir separation factor (R L ) indicate a favorable Cs adsorption. The values of mean free energy of sorption (E) at various temperatures ranged from 10.5 to 11.1 kJ/mol, which indicates that the sorption process follows chemisorption.

show abstract

Assessment of synthetic zeolite Na A–X as sorbing barrier for strontium in a radioactive disposal facility

Cited by 96 publications

References 42 publications

Influence of pH, concentration and ionic strength during batch and flow-through continuous stirred reactor experiments of Sr2+-adsorption onto montmorillonite

Influence of pH, concentration and ionic strength during batch and flow-through continuous stirred reactor experiments of Sr2+-adsorption onto montmorillonite

Effect of the synthesis temperature of sodium nonatitanate on batch kinetics of strontium-ion adsorption from aqueous solution

Sorption of Cesium on Clay Colloids: Kinetic and Thermodynamic Studies

Contact Info

Product

Resources

About