Chromium (VI) ion adsorption features of chitosan film and its chitosan/zeolite conjugate 13X film

• Published in: Molecules (Basel, Switzerland) Vol. 16; no. 5; pp. 3569 - 3579
• Main Authors: Batista, Anabelle C L, Villanueva, Emílio R, Amorim, Rosa Valéria S, Tavares, Maria Teresa, Campos-Takaki, Galba M
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 28-04-2011; MDPI
• Subjects: Adsorption; chitosan; Chitosan - chemistry; chromium; Chromium - chemistry; Heavy metals; Hydrogen bonds; Membranes, Artificial; Vibration; zeolite; Zeolites; Zeolites - chemistry; Brazil
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules16053569

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.