title: Chromium (VI) ion adsorption features of chitosan film and its chitosan/zeolite conjugate 13X film.
abstract: 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.
authors.affiliation: Rede Nordeste de Biotecnologia (RENORBIO), Universidade Estadual do Ceará, Av. Paranjana, 1.700, Campus do Itaperi, 60740-000 Fortaleza, CE, Brazil.
authors.forename: Anabelle C L
authors.initials: AC
authors.lastname: Batista
authors.forename: Emílio R
authors.initials: ER
authors.lastname: Villanueva
authors.forename: Rosa Valéria S
authors.initials: RV
authors.lastname: Amorim
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Tavares
authors.forename: Galba M
authors.initials: GM
authors.lastname: Campos-Takaki
mesh_terms: D000327:Adsorption; D048271:Chitosan / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D008567:Membranes, Artificial; D017641:Zeolites / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D002857:Chromium; D017641:Zeolites; D048271:Chitosan