title: Adsorption of an anionic azo dye by cross-linked chitosan/bentonite composite.
abstract: In this study, cross-linked chitosan (CCS)/bentonite (BT) composite was prepared by the intercalation of chitosan in bentonite and the cross-linking reaction between chitosan and glutaraldehyde. CCS/BT composite was characterized by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermal gravimetric analyses (TGA). Their adsorption characteristics were assessed by using an azo dye (Amido Black 10B) as a model adsorbate. The adsorption of Amido Black 10B onto the CCS/BT composite was found to be optimal at pH 2. The adsorption isotherm was well described by the Langmuir model and the maximum adsorption capacity was 323.6 mg/g at 293K and pH 2. Amido Black 10B adsorption kinetics followed a pseudo-second-order kinetic model. The calculated thermodynamic parameters showed that the adsorption of Amido Black 10B by CCS/BT composite was spontaneous and endothermic in nature.
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Xi'an Institute of Geology and Mineral Resource, Xi'an, Shaanxi 710054, China.
authors.forename: Bingchao
authors.initials: B
authors.lastname: Yang
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Lujie
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: hrh20022002@163.com.
authors.forename: Ruihua
authors.initials: R
authors.lastname: Huang
mesh_terms: D000327:Adsorption; D000580:Amido Black / Q000302:isolation & purification*; D000838:Anions; D001546:Bentonite / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D004396:Coloring Agents / Q000302:isolation & purification*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D000838:Anions; D004396:Coloring Agents; D003432:Cross-Linking Reagents; D012996:Solutions; D001546:Bentonite; D048271:Chitosan; D000580:Amido Black
keywords: Adsorption; Amido Black 10B; CCS/BT composite; Isotherm models; Kinetics; Thermodynamics