title: Adsorption of chromium (VI) by ethylenediamine-modified cross-linked magnetic chitosan resin: isotherms, kinetics and thermodynamics.
abstract: The adsorption of chromium (VI) ions from aqueous solution by ethylenediamine-modified cross-linked magnetic chitosan resin (EMCMCR) was studied in a batch adsorption system. Chromium (VI) removal is pH dependent and the optimum adsorption was observed at pH 2.0. The adsorption rate was extremely fast and the equilibrium was established within 6-10min. The adsorption data could be well interpreted by the Langmuir and Temkin model. The maximum adsorption capacities obtained from the Langmuir model are 51.813mgg(-1), 48.780mgg(-1) and 45.872mgg(-1) at 293, 303 and 313K, respectively. The adsorption process could be described by pseudo-second-order kinetic model. The intraparticle diffusion study revealed that film diffusion might be involved in the present case. Thermodynamic parameters revealed the feasibility, spontaneity and exothermic nature of adsorption. The sorbents were successfully regenerated using 0.1N NaOH solutions.
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Xin-jiang
authors.initials: XJ
authors.lastname: Hu
authors.forename: Jing-song
authors.initials: JS
authors.lastname: Wang
authors.forename: Yun-guo
authors.initials: YG
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Guang-ming
authors.initials: GM
authors.lastname: Zeng
authors.forename: Zheng-lei
authors.initials: ZL
authors.lastname: Bao
authors.forename: Xiao-xia
authors.initials: XX
authors.lastname: Zeng
authors.forename: An-wei
authors.initials: AW
authors.lastname: Chen
authors.forename: Fei
authors.initials: F
authors.lastname: Long
mesh_terms: D000327:Adsorption; D000465:Algorithms; D048271:Chitosan / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D003432:Cross-Linking Reagents; D004058:Diffusion; D005029:Ethylenediamines / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D013696:Temperature; D013816:Thermodynamics
chemical_list: D003432:Cross-Linking Reagents; D005029:Ethylenediamines; D002857:Chromium; C074702:chromium hexavalent ion; D048271:Chitosan