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Adsorption of chromium(VI) from aqueous solutions using an imidazole functionalized adsorbent / Hyung-Jun Park in Industrial & engineering chemistry research, Vol. 47 N°10 (Mai 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°10 (Mai 2008) . - p. 3401–3409 Titre : Adsorption of chromium(VI) from aqueous solutions using an imidazole functionalized adsorbent Type de document : texte imprimé Auteurs : Hyung-Jun Park, Auteur ; Lawrence L. Tavlarides, Auteur Année de publication : 2008 Article en page(s) : p. 3401–3409 Note générale : Bibliogr. p. 3408-3409 Langues : Anglais (eng) Mots-clés : Chromium(VI)  --  separation;  Imidazole  functionalized  adsorbent;  Sol-gel  synthesis  method Résumé : Separation of chromium(VI) from aqueous solutions is investigated using an imidazole functionalized sol−gel adsorbent. This adsorbent has been formed by the sol−gel synthesis method. The speciation diagram of Cr(VI) in an aqueous system with varying pH is studied by analyses of the equilibria equations. Batch adsorption equilibrium studies show a decrease in chromium uptake capacity with increase in pH in the range from 2 to 9, and the uptake capacity at pH 2.5 is found to be 2.93 mmol/g (152 mg/g). The Langmuir adsorption isotherm gives a satisfactory fit of the adsorption data. A kinetics study conducted with different concentrations of chromium(VI) in a batch reactor shows a rapid rate of adsorption. The adsorbent shows a high selectivity toward Cr(VI) and negligible adsorption of Cu(II), Ni(II), and Zn(II). Adsorption tests in a fixed bed column show a sharp breakthrough curve. Stripping of the chromium-loaded column bed is achieved using 4 M HNO3. Twenty cycles of adsorption and desorption process are performed for SOL-IPS adsorbent. The adsorbent maintains 90% of original capacity during 15 cycles, and loss of 25% of capacity until 20 cycles of operation. The imidazole functional adsorbent is demonstrated to be an effective sorbent material for the separation of chromium(VI) from aqueous solutions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie7017096 [article] Adsorption of chromium(VI) from aqueous solutions using an imidazole functionalized adsorbent [texte imprimé] / Hyung-Jun Park, Auteur ; Lawrence L. Tavlarides, Auteur . - 2008 . - p. 3401–3409. Bibliogr. p. 3408-3409 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°10 (Mai 2008) . - p. 3401–3409 Mots-clés : Chromium(VI)  --  separation;  Imidazole  functionalized  adsorbent;  Sol-gel  synthesis  method Résumé : Separation of chromium(VI) from aqueous solutions is investigated using an imidazole functionalized sol−gel adsorbent. This adsorbent has been formed by the sol−gel synthesis method. The speciation diagram of Cr(VI) in an aqueous system with varying pH is studied by analyses of the equilibria equations. Batch adsorption equilibrium studies show a decrease in chromium uptake capacity with increase in pH in the range from 2 to 9, and the uptake capacity at pH 2.5 is found to be 2.93 mmol/g (152 mg/g). The Langmuir adsorption isotherm gives a satisfactory fit of the adsorption data. A kinetics study conducted with different concentrations of chromium(VI) in a batch reactor shows a rapid rate of adsorption. The adsorbent shows a high selectivity toward Cr(VI) and negligible adsorption of Cu(II), Ni(II), and Zn(II). Adsorption tests in a fixed bed column show a sharp breakthrough curve. Stripping of the chromium-loaded column bed is achieved using 4 M HNO3. Twenty cycles of adsorption and desorption process are performed for SOL-IPS adsorbent. The adsorbent maintains 90% of original capacity during 15 cycles, and loss of 25% of capacity until 20 cycles of operation. The imidazole functional adsorbent is demonstrated to be an effective sorbent material for the separation of chromium(VI) from aqueous solutions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie7017096

Adsorption of neodymium(III) from aqueous solutions using a phosphorus functionalized adsorbent / Hyung-Jun Park in Industrial & engineering chemistry research, Vol. 49 N° 24 (Décembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12567–12575 Titre : Adsorption of neodymium(III) from aqueous solutions using a phosphorus functionalized adsorbent Type de document : texte imprimé Auteurs : Hyung-Jun Park, Auteur ; Lawrence L. Tavlarides, Auteur Année de publication : 2011 Article en page(s) : pp. 12567–12575 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Adsorption  neodymium  Aqueous  solutions Résumé : Separation of neodymium(III) from aqueous solutions is investigated using an phosphorus based sol−gel adsorbent. This adsorbent has been formed by the sol−gel synthesis method. The speciation diagram of Nd(III) in an aqueous phase with varying pH is studied by analyses of the equilibria equations. Batch adsorption equilibrium studies show an increase in neodymium uptake capacity with increase in pH in the range from pH 0.5 to pH 6.5, and the maximum uptake capacity at pH 6 is observed to be 1.13 mmol/g (160 mg/g). The equilibrium adsorption isotherm gives a satisfactory fit of the adsorption data. A kinetics study conducted with different concentrations and particle sizes of neodymium(III) in a batch reactor shows a high rate of adsorption. The adsorbent shows a capability of selectivity toward Nd(III) and other rare earths. Adsorption tests in a fixed bed column show a sharp breakthrough curve. Stripping of the neodymium-loaded column bed is achieved using 1 M HNO3. The material also has sustainable stability over repeated metal loading and stripping in a column. In addition to the experimental studies, the adsorption processes in batch and packed column systems are successfully modeled by using a pore diffusion model, and the results are presented. The organophosphorus functionalized adsorbent is demonstrated to be an effective sorbent material for the separation of neodymium(III) from aqueous solutions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100403b [article] Adsorption of neodymium(III) from aqueous solutions using a phosphorus functionalized adsorbent [texte imprimé] / Hyung-Jun Park, Auteur ; Lawrence L. Tavlarides, Auteur . - 2011 . - pp. 12567–12575. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12567–12575 Mots-clés : Adsorption  neodymium  Aqueous  solutions Résumé : Separation of neodymium(III) from aqueous solutions is investigated using an phosphorus based sol−gel adsorbent. This adsorbent has been formed by the sol−gel synthesis method. The speciation diagram of Nd(III) in an aqueous phase with varying pH is studied by analyses of the equilibria equations. Batch adsorption equilibrium studies show an increase in neodymium uptake capacity with increase in pH in the range from pH 0.5 to pH 6.5, and the maximum uptake capacity at pH 6 is observed to be 1.13 mmol/g (160 mg/g). The equilibrium adsorption isotherm gives a satisfactory fit of the adsorption data. A kinetics study conducted with different concentrations and particle sizes of neodymium(III) in a batch reactor shows a high rate of adsorption. The adsorbent shows a capability of selectivity toward Nd(III) and other rare earths. Adsorption tests in a fixed bed column show a sharp breakthrough curve. Stripping of the neodymium-loaded column bed is achieved using 1 M HNO3. The material also has sustainable stability over repeated metal loading and stripping in a column. In addition to the experimental studies, the adsorption processes in batch and packed column systems are successfully modeled by using a pore diffusion model, and the results are presented. The organophosphorus functionalized adsorbent is demonstrated to be an effective sorbent material for the separation of neodymium(III) from aqueous solutions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100403b

Germanium(IV) adsorption from aqueous solution using a kelex-100 functional adsorbent / Hyung-Jun Park in Industrial & engineering chemistry research, Vol. 48 N° 8 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 8 (Avril 2009) . - pp. 4014–4021 Titre : Germanium(IV) adsorption from aqueous solution using a kelex-100 functional adsorbent Type de document : texte imprimé Auteurs : Hyung-Jun Park, Auteur ; Lawrence L. Tavlarides, Auteur Année de publication : 2009 Article en page(s) : pp. 4014–4021 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Germanium  Acid  solution  systems  Kelex-100  Sol−gel  adsorbent  Aqueous  solution Résumé : The removal of germanium from acid solution systems using a Kelex-100 [7-(4-ethyl-1-methyloctyl)-8-hydroxyquinoline] functional sol−gel adsorbent was investigated. Kelex-100 has been used for separating metals such as Ga(III), Co(II), Cd(II), Pb(II), and Cu(II) from aqueous solution by solvent extraction and liquid membranes. The goal of this work was to demonstrate that elutable mesoporous organo-ceramic adsorbents based on Kelex-100 can be synthesized for the selective separation of germanium from simulated leachate solution. The speciation diagram of Ge(IV) in an aqueous system with varying pH was prepared and evaluated by analysis of the equilibrium equations. The Langmuir adsorption isotherm was found to provide a satisfactory fit of the adsorption data, and the uptake capacity at pH 6.0 was found to be 0.33 mmol/g (23 mg/g). A kinetics study conducted on a germanium(IV) solution in a batch reactor at different pH values showed a high rate of adsorption relative to other adsorbents [Inukai et al. Anal. Sci.2001, 1, 1117−1120; Marco et al. Carbon2007, 45 (13), 2519−2528; Pokrovsky et al. Geochim. Cosmochim. Acta2006, 70, 3325−3341]. The adsorbent exhibited a high selectivity toward Ge(IV) and negligible adsorption of As(II), Sb(II), Ni(II), and Zn(II). Adsorption tests in a fixed-bed column showed a sharp breakthrough curve. Stripping of the germanium-loaded column bed was achieved using 1 M HCl. Eleven cycles of the adsorption and desorption process were performed with this Kelex-100 functional adsorbent, named SOL-KELEX. The adsorbent maintained 70% of its original capacity through six cycles and lost 50% of its capacity through 11 cycles of operation. The Kelex-100 functional adsorbent was found to be an effective sorbent material for the separation of germanium(IV) from aqueous solutions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801733d [article] Germanium(IV) adsorption from aqueous solution using a kelex-100 functional adsorbent [texte imprimé] / Hyung-Jun Park, Auteur ; Lawrence L. Tavlarides, Auteur . - 2009 . - pp. 4014–4021. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 8 (Avril 2009) . - pp. 4014–4021 Mots-clés : Germanium  Acid  solution  systems  Kelex-100  Sol−gel  adsorbent  Aqueous  solution Résumé : The removal of germanium from acid solution systems using a Kelex-100 [7-(4-ethyl-1-methyloctyl)-8-hydroxyquinoline] functional sol−gel adsorbent was investigated. Kelex-100 has been used for separating metals such as Ga(III), Co(II), Cd(II), Pb(II), and Cu(II) from aqueous solution by solvent extraction and liquid membranes. The goal of this work was to demonstrate that elutable mesoporous organo-ceramic adsorbents based on Kelex-100 can be synthesized for the selective separation of germanium from simulated leachate solution. The speciation diagram of Ge(IV) in an aqueous system with varying pH was prepared and evaluated by analysis of the equilibrium equations. The Langmuir adsorption isotherm was found to provide a satisfactory fit of the adsorption data, and the uptake capacity at pH 6.0 was found to be 0.33 mmol/g (23 mg/g). A kinetics study conducted on a germanium(IV) solution in a batch reactor at different pH values showed a high rate of adsorption relative to other adsorbents [Inukai et al. Anal. Sci.2001, 1, 1117−1120; Marco et al. Carbon2007, 45 (13), 2519−2528; Pokrovsky et al. Geochim. Cosmochim. Acta2006, 70, 3325−3341]. The adsorbent exhibited a high selectivity toward Ge(IV) and negligible adsorption of As(II), Sb(II), Ni(II), and Zn(II). Adsorption tests in a fixed-bed column showed a sharp breakthrough curve. Stripping of the germanium-loaded column bed was achieved using 1 M HCl. Eleven cycles of the adsorption and desorption process were performed with this Kelex-100 functional adsorbent, named SOL-KELEX. The adsorbent maintained 70% of its original capacity through six cycles and lost 50% of its capacity through 11 cycles of operation. The Kelex-100 functional adsorbent was found to be an effective sorbent material for the separation of germanium(IV) from aqueous solutions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801733d