Chromium (VI) ion adsorption features of chitosan film and its chitosan/zeolite...

• Author(s): Batista, Anabelle C. L. ; Villanueva, Emílio R. ; Amorim, Rosa Valéria S. ; Tavares, M. T. ; Takaki, G. M. Campos
• Date: 2011
• Persistent ID: http://hdl.handle.net/1822/16630
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Adsorption; Chitosan; Chromium; Chiyosan/zeolites conjugates
• Document Type: Article
• Language: English

Description

This research evaluated the importance of the adsorption properties of chitosan a chitosan/zeolite conjugate film for the removal of Cr(VI) ions from solutions in the 5–260 mg/L concentration range, when the pH was adjusted to 4.0 and 6.0. The uptake capacities of the films formed by chitosan and by the chitosan/zeolite conjugate were calculated by mass balance. The equilibrium isotherms were fitted to the Langmuir, Freundlich and Redlich-Peterson models. The chitosan film seems to be a good sorbent for Cr(VI) at pH 4, but its physical instability suggests the need for a more resilient support. Due to this fact zeolite was added to the chitosan matrix in solution and a chitosan/zeolite (CS/Zeo) film was thus formed. The solubility of the film and the characterization of the different matrices by FTIR, TGA and X-Ray showed that a cross-linked structure was formed between the chitosan and zeolite and the solubility of the film increased. In this study, the low manufacturing cost of the CS/Zeo matrix, the good uptake of Cr(VI) at acidic pH (17.28 mg/g) and the non desorption of Cr(VI) from the film in water suggests this combination should be tested in industrial environment.