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Kinetics and mechanism of tartrazine adsorption onto chitin and chitosan / Guilherme L. Dotto in Industrial & engineering chemistry research, Vol. 51 N° 19 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6862-6868 Titre : Kinetics and mechanism of tartrazine adsorption onto chitin and chitosan Type de document : texte imprimé Auteurs : Guilherme L. Dotto, Auteur ; Mery L. G. Vieira, Auteur ; Luiz A. A. Pinto, Auteur Année de publication : 2012 Article en page(s) : pp. 6862-6868 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption  Kinetics Résumé : In this work the kinetics and mechanisms of tartrazine adsorption onto chitin and chitosan were studied at different pH values (3, 5, 7, 9 and 11). Five models were employed to elucidate the adsorption kinetics. The adsorption mechanisms were verified by use of models based on mass transfer and elemental analysis. The adsorption capacity was increased with pH decrease, reaching maximum values at pH 3. The maximum values were 30 mg·g―1 and 350 mg·g―1 for chitin and chitosan, respectively. For both adsorbents a fast kinetic was observed, and the Avrami model was the more adequate to fitting the experimental data. Tartrazine adsorption onto chitin occurred only by film diffusion. In the chitosan case, adsorption occurred by film and intraparticle diffusion, however, intraparticle diffusion was the rate-limiting step. At pH 3, tartrazine adsorption onto chitin and chitosan occurred by chemical interactions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900239 [article] Kinetics and mechanism of tartrazine adsorption onto chitin and chitosan [texte imprimé] / Guilherme L. Dotto, Auteur ; Mery L. G. Vieira, Auteur ; Luiz A. A. Pinto, Auteur . - 2012 . - pp. 6862-6868. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 19 (Mai 2012) . - pp. 6862-6868 Mots-clés : Adsorption  Kinetics Résumé : In this work the kinetics and mechanisms of tartrazine adsorption onto chitin and chitosan were studied at different pH values (3, 5, 7, 9 and 11). Five models were employed to elucidate the adsorption kinetics. The adsorption mechanisms were verified by use of models based on mass transfer and elemental analysis. The adsorption capacity was increased with pH decrease, reaching maximum values at pH 3. The maximum values were 30 mg·g―1 and 350 mg·g―1 for chitin and chitosan, respectively. For both adsorbents a fast kinetic was observed, and the Avrami model was the more adequate to fitting the experimental data. Tartrazine adsorption onto chitin occurred only by film diffusion. In the chitosan case, adsorption occurred by film and intraparticle diffusion, however, intraparticle diffusion was the rate-limiting step. At pH 3, tartrazine adsorption onto chitin and chitosan occurred by chemical interactions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25900239