Documents disponibles écrits par cet auteur

Batch removal of aqueous Cu2+ ions using nanoparticles of zero-valent iron / Duygu Karabelli in Industrial & engineering chemistry research, Vol. 47 n°14 (Juillet 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°14 (Juillet 2008) . - p. 4758–4764 Titre : Batch removal of aqueous Cu2+ ions using nanoparticles of zero-valent iron : a study of the capacity and mechanism of uptake Type de document : texte imprimé Auteurs : Duygu Karabelli, Auteur ; Çagri Üzüm, Auteur ; Talal Shahwan, Auteur ; Ahmet E. Eroglu, Auteur Année de publication : 2008 Article en page(s) : p. 4758–4764 Langues : Anglais (eng) Mots-clés : Cu2+  ions;  Zero-valent  iron;  X-ray  photoelectron  spectroscopy;  X-ray  diffraction Résumé : In this study, nZVI prepared by borohydride reduction was applied for the removal of Cu2+ ions under a variety of experimental conditions. The uptake experiments investigated the effects of initial concentration, contact time, pH, and repetitive loading on the extent of retardation of Cu2+ ions. Within the applied conditions, the sorbent demonstrated fast uptake kinetics and outstanding fixation abilities up to an initial Cu2+ concentration of 200.0 mg/L. Partitioning of Cu2+ ions between liquid and solid phases demonstrated an isotherm of L-type. Within the studied conditions, the capacity of uptake was found to be 250 mg of Cu2+ per g of nZVI. According to X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) results, Cu2+ ions were sorbed primarily via a redox mechanism that resulted in the formation of Cu2O and Cu0. The contact of iron nanoparticles with aqueous media caused extensive formation of iron oxide. However, the material did not completely lose its removal capacity and was repeatedly applied at low concentrations for further uptake trials. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800081s [article] Batch removal of aqueous Cu2+ ions using nanoparticles of zero-valent iron : a study of the capacity and mechanism of uptake [texte imprimé] / Duygu Karabelli, Auteur ; Çagri Üzüm, Auteur ; Talal Shahwan, Auteur ; Ahmet E. Eroglu, Auteur . - 2008 . - p. 4758–4764. Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°14 (Juillet 2008) . - p. 4758–4764 Mots-clés : Cu2+  ions;  Zero-valent  iron;  X-ray  photoelectron  spectroscopy;  X-ray  diffraction Résumé : In this study, nZVI prepared by borohydride reduction was applied for the removal of Cu2+ ions under a variety of experimental conditions. The uptake experiments investigated the effects of initial concentration, contact time, pH, and repetitive loading on the extent of retardation of Cu2+ ions. Within the applied conditions, the sorbent demonstrated fast uptake kinetics and outstanding fixation abilities up to an initial Cu2+ concentration of 200.0 mg/L. Partitioning of Cu2+ ions between liquid and solid phases demonstrated an isotherm of L-type. Within the studied conditions, the capacity of uptake was found to be 250 mg of Cu2+ per g of nZVI. According to X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) results, Cu2+ ions were sorbed primarily via a redox mechanism that resulted in the formation of Cu2O and Cu0. The contact of iron nanoparticles with aqueous media caused extensive formation of iron oxide. However, the material did not completely lose its removal capacity and was repeatedly applied at low concentrations for further uptake trials. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800081s

Synthesis of aminopropyl triethoxysilane - functionalized silica and its application in speciation studies of vanadium(IV) and vanadium (V) / Asli Erdem in Chemical engineering journal, Vol. 174 N° 1 (Octobre 2011) 

Public ISBD [article]  in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp.76-85 Titre : Synthesis of aminopropyl triethoxysilane - functionalized silica and its application in speciation studies of vanadium(IV) and vanadium (V) Type de document : texte imprimé Auteurs : Asli Erdem, Auteur ; Talal Shahwan, Auteur ; Ali Cagir, Auteur Année de publication : 2012 Article en page(s) : pp.76-85 Note générale : Génie chimique Langues : Anglais (eng) Mots-clés : Vanadium(IV)  Vanadium(V)Amine-functionalized  silica  Speciation  Inductively  coupled  plasma  mass  spectrometry Résumé : A solid phase extraction sorbent, aminopropyltriethoxysilane-functionalized silica was prepared and used for vanadiumspeciation prior to inductively coupled plasma mass spectrometric determination. The necessary sorption parameters such as sorption pH, reaction temperature, sorbent amount and sample volume were optimized. The sorption for V(V) and V(IV) under the optimized conditions was 98% (±1) and was lower than 10%, respectively. The sorption process was investigated both from a kinetic perspective and also in terms of Freundlich, Dubinin-Radushkevich and Langmuir isotherm models to characterize the uptake of vanadate ion by the functionalized silica. Desorption from the sorbent was realized with 0.5 mol L−1 thiourea prepared in 0.2 mol L−1 HCl. Among the possible interfering species tested, Te(IV), Se(IV), Se(VI) and Fe(III) showed interference effects with V(V) signal. The validity of the method was first checked via spike recovery experiments with four different types of water; namely ultra pure, bottled drinking, tap, and sea water for different concentrations of V(V). The percent recovery values changed between 87 and 108 for all water types. The accuracy of the proposed methodology was also checked by analyzing a standard reference material (NIST, SRM 1643e) and a good agreement was found between the determined and the certified value. The proposed methodology has also been shown to be applicable for the separate sorption of V(V) in the absence/presence of V(IV) and for the sorption of both V(IV) and V(V) in waters. The amount of V(IV) can then be determined from the difference. ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science/article/pii/S1385894711009958 [article] Synthesis of aminopropyl triethoxysilane - functionalized silica and its application in speciation studies of vanadium(IV) and vanadium (V) [texte imprimé] / Asli Erdem, Auteur ; Talal Shahwan, Auteur ; Ali Cagir, Auteur . - 2012 . - pp.76-85. Génie chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp.76-85 Mots-clés : Vanadium(IV)  Vanadium(V)Amine-functionalized  silica  Speciation  Inductively  coupled  plasma  mass  spectrometry Résumé : A solid phase extraction sorbent, aminopropyltriethoxysilane-functionalized silica was prepared and used for vanadiumspeciation prior to inductively coupled plasma mass spectrometric determination. The necessary sorption parameters such as sorption pH, reaction temperature, sorbent amount and sample volume were optimized. The sorption for V(V) and V(IV) under the optimized conditions was 98% (±1) and was lower than 10%, respectively. The sorption process was investigated both from a kinetic perspective and also in terms of Freundlich, Dubinin-Radushkevich and Langmuir isotherm models to characterize the uptake of vanadate ion by the functionalized silica. Desorption from the sorbent was realized with 0.5 mol L−1 thiourea prepared in 0.2 mol L−1 HCl. Among the possible interfering species tested, Te(IV), Se(IV), Se(VI) and Fe(III) showed interference effects with V(V) signal. The validity of the method was first checked via spike recovery experiments with four different types of water; namely ultra pure, bottled drinking, tap, and sea water for different concentrations of V(V). The percent recovery values changed between 87 and 108 for all water types. The accuracy of the proposed methodology was also checked by analyzing a standard reference material (NIST, SRM 1643e) and a good agreement was found between the determined and the certified value. The proposed methodology has also been shown to be applicable for the separate sorption of V(V) in the absence/presence of V(IV) and for the sorption of both V(IV) and V(V) in waters. The amount of V(IV) can then be determined from the difference. ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science/article/pii/S1385894711009958