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Adsorptive preconcentration of uranium in hydrogels from seawater and aqueous solutions / Sadananda Das in Industrial & engineering chemistry research, Vol. 48 N° 14 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 14 (Juillet 2009) . - pp. 6789–6796 Titre : Adsorptive preconcentration of uranium in hydrogels from seawater and aqueous solutions Type de document : texte imprimé Auteurs : Sadananda Das, Auteur ; Ashok K. Pandey, Auteur ; T. Vasudevan, Auteur Année de publication : 2009 Article en page(s) : pp. 6789–6796 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Cross-linked  hydrogels  Bulk  polymerization  Seawater  samples  Aqueous  solutions  Adsorption Résumé : Cross-linked hydrogels containing poly(ethylene glycol methacrylate phosphate) (EGMP), poly(2-acrylamido-2-methyl-1-propane sulfonate) (AMPS), poly(acrylamidoxime) (AO), and AO along with different acidic (acrylic acid (AA), methacrylic acid (MAA), AMPS, and EGMP) and basic (3-(acrylamido propyl) trimethylammonium chloride (APTAC)) comonomers were prepared by UV-initiated bulk polymerization. These hydrogels were characterized in terms of their chemical structure and U(VI)-uptake behavior from aqueous and seawater samples. Except AMPS hydrogel, all these hydrogels were found to sorb U(VI) quantitatively (≈90%) from the seawater. The U(VI)-sorption kinetics in EGMP and AO+MAA (60:40) hydrogels were found to be faster than other hydrogels under seawater conditions. The presence of a strong acid (−SO3H) comonomer with AO retards the overall kinetics involve in the U(VI) sorption from seawater. It was also observed that the U(VI) sorption kinetics was highly dependent on the composition of the acidic and AO groups in the hydrogel. The uptake of U(VI) from acidic solution in AO+MAA hydrogel was found to be dependent on the acidity of the feed solution, and there was no uptake of U(VI) in this hydrogel from solution containing 1 mol L−1 HNO3. Contrary to this, EGMP hydrogel could sorb the U(VI) from solution containing high concentration of HNO3. This indicated that EGMP hydrogel can also be used for U(VI) preconcentration from the nuclear waste. U(VI) complexed in EGMP hydrogel and AO+MAA could be desorbed by their equilibration with 0.5 mol L−1 Na2CO3 and 1 mol L−1 HCl/HNO3, respectively. The mechanism of sorption of U(VI) in the hydrogels was studied to understand the factors that control the U(VI) sorption from seawater. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801912n [article] Adsorptive preconcentration of uranium in hydrogels from seawater and aqueous solutions [texte imprimé] / Sadananda Das, Auteur ; Ashok K. Pandey, Auteur ; T. Vasudevan, Auteur . - 2009 . - pp. 6789–6796. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 14 (Juillet 2009) . - pp. 6789–6796 Mots-clés : Cross-linked  hydrogels  Bulk  polymerization  Seawater  samples  Aqueous  solutions  Adsorption Résumé : Cross-linked hydrogels containing poly(ethylene glycol methacrylate phosphate) (EGMP), poly(2-acrylamido-2-methyl-1-propane sulfonate) (AMPS), poly(acrylamidoxime) (AO), and AO along with different acidic (acrylic acid (AA), methacrylic acid (MAA), AMPS, and EGMP) and basic (3-(acrylamido propyl) trimethylammonium chloride (APTAC)) comonomers were prepared by UV-initiated bulk polymerization. These hydrogels were characterized in terms of their chemical structure and U(VI)-uptake behavior from aqueous and seawater samples. Except AMPS hydrogel, all these hydrogels were found to sorb U(VI) quantitatively (≈90%) from the seawater. The U(VI)-sorption kinetics in EGMP and AO+MAA (60:40) hydrogels were found to be faster than other hydrogels under seawater conditions. The presence of a strong acid (−SO3H) comonomer with AO retards the overall kinetics involve in the U(VI) sorption from seawater. It was also observed that the U(VI) sorption kinetics was highly dependent on the composition of the acidic and AO groups in the hydrogel. The uptake of U(VI) from acidic solution in AO+MAA hydrogel was found to be dependent on the acidity of the feed solution, and there was no uptake of U(VI) in this hydrogel from solution containing 1 mol L−1 HNO3. Contrary to this, EGMP hydrogel could sorb the U(VI) from solution containing high concentration of HNO3. This indicated that EGMP hydrogel can also be used for U(VI) preconcentration from the nuclear waste. U(VI) complexed in EGMP hydrogel and AO+MAA could be desorbed by their equilibration with 0.5 mol L−1 Na2CO3 and 1 mol L−1 HCl/HNO3, respectively. The mechanism of sorption of U(VI) in the hydrogels was studied to understand the factors that control the U(VI) sorption from seawater. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801912n