Adsorption of Cr(VI) using Fe-crosslinked chitosan complex (Ch-Fe).

Autor: Zimmermann AC; Núcleo de Investigações Químico-Farmacêuticas (NIQFAR), Universidade do Vale do Itajaí, Itajaí, 88302-202, Santa Catarina, Brazil., Mecabô A, Fagundes T, Rodrigues CA
Jazyk: angličtina
Zdroj: Journal of hazardous materials [J Hazard Mater] 2010 Jul 15; Vol. 179 (1-3), pp. 192-6. Date of Electronic Publication: 2010 Mar 06.
DOI: 10.1016/j.jhazmat.2010.02.078
Abstrakt: In the present investigation, Fe-chitosan crosslinked is used as adsorbent for the removal of chromium from aqueous solutions. The influence of pH, temperature and other ions was evaluated. pH 2.0 was found to be the optimum pH for adsorption of Cr(VI) onto Ch-Fe. Coordination of unsaturated sites for the iron(III) complex of polymer were considered to be the adsorption sites for Cr(VI) species, the predominant species being HCrO(4)(-). The Langmuir and Langmuir-Freundlich adsorption isotherm models were applied to describe the isotherm parameter for Cr(VI) adsorption. The results indicate that the Langmuir-Freundlich adsorption model and maximum adsorption capacity was calculated as 295 mg/g at 25 degrees C, with pH 4.7. Cr(VI) uptake on the adsorbent decreased from 295 mg/g at 25 degrees C to 209 mg/g at 65 degrees C. Rate constants as a function of temperature were evaluated with the help of a proposed second order kinetic model. The other coexisting ions, nitrate, chlorides and sulphate influenced Cr(VI) adsorption.
(2010 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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