title: Adsorptive removal of Congo red from aqueous solutions using crosslinked chitosan and crosslinked chitosan immobilized bentonite.
abstract: Batch experiments were executed to investigate the removal of Congo red (CR) from aqueous solutions using the crosslinked chitosan (CCS) and crosslinked chitosan immobilized bentonite (CCS/BT composite). The CCS and CCS/BT composite were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. The removal of CR was examined as a function of pH value of CR solution, contact time, and inorganic sodium salt and ionic strength. The equilibrium data of CCS and CCS/BT composite agreed well with the Langmuir model. The adsorption capacities of CCS and CCS/BT composite at 298K and natural pH value were 405 and 500 mg/g, respectively. The kinetic data correlated well with the pseudo-second-order model. The adsorption of CR onto the CCS was mainly controlled by chemisorption while the adsorption of CR onto the CCS/BT composite was controlled by chemisorption and the electrostatic attraction.
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
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.
authors.forename: Pan
authors.initials: P
authors.lastname: Hu
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D003224:Congo Red / Q000737:chemistry* / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009994:Osmolar Concentration; D012492:Salts / Q000737:chemistry; D012996:Solutions; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification*
chemical_list: D012492:Salts; D012996:Solutions; D014874:Water Pollutants, Chemical; D014867:Water; D001546:Bentonite; D003224:Congo Red; D048271:Chitosan
keywords: Adsorption isotherm; Bentonite; Chitosan