Chitosan scaffold as an alternative adsorbent for the removal of hazardous food dyes from aqueous solutions

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:424

Article

Esquerdo, V. M.¹  Cadaval, T. R. S., Jr.¹  Dotto, G. L.²  Pinto, L. A. A.¹ 

[1] Fed Univ Rio Grande, Sch Chem & Food, Unit Operat Lab, FURG, BR-96201900 Rio Grande, RS, Brazil

[2] Univ Fed Santa Maria, Dept Chem Engn, BR-97105900 Santa Maria, RS, Brazil

关键词: Chitosan scaffold;    Dyes;    Thermodynamic;    Two-step Langmuir model;   

DOI  :  10.1016/j.jcis.2014.02.028

来源: Elsevier

【 摘 要 】

Hypothesis: The dye adsorption with chitosan is considered an eco-friendly alternative technology in relation to the existing water treatment technologies. However, the application of chitosan for dyes removal is limited, due to its low surface area and porosity. Then we prepared a chitosan scaffold with a megaporous structure as an alternative adsorbent to remove food dyes from solutions. Experiments: The chitosan scaffold was characterized by infrared spectroscopy, scanning electron microscopy and structural characteristics. The potential of chitosan scaffold to remove five food dyes from solutions was investigated by equilibrium isotherms and thermodynamic study. The scaffold-dyes interactions were elucidated, and desorption studies were carried out. Findings: The chitosan scaffold presented pore sizes from 50 to 200 gm, porosity of 92.2 +/- 1.2% and specific surface area of 1135 +/- 2 m(2) g(-1). The two-step Langmuir model was suitable to represent the equilibrium data. The adsorption was spontaneous, favorable, exothermic and enthalpy-controlled process. Electrostatic interactions occurred between chitosan scaffold and dyes. Desorption was possible with NaOH solution (0.10 mol L-1). The chitosan megaporous scaffold showed good structural characteristics and high adsorption capacities (788-3316 mg g(-1)). (C) 2014 Elsevier Inc. All rights reserved.

【 授权许可】

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