title: Adsorption behavior of Hg2+ in aqueous solutions on a novel chelating cross-linked chitosan microsphere.
abstract: In this study, cross-linked chitosan microspheres (CCTS) was synthesized from chitosan and epichlorohydrin (ECH), then, 2-(chloromethyl) benzimidazole (CBM) was introduced to modify CCTS as the ligand. The resulting CBM-chitosan was characterized by EA, FTIR and TGA, and tested for metal adsorption. Results showed that CBM-chitosan has a relatively high selectivity toward Hg(2+). Equilibrium data were fitted well with Langmuir isotherms with the maximum adsorption capacity of 257.8 mg/g for Hg(2+). Both kinetics and thermodynamic parameters of the adsorption process were obtained. The data indicated that adsorption process was exothermic spontaneous reaction and kinetically proceeded according to Second-order kinetics model. CBM-chitosan can be eluted effectively using 1.0 mol/L HCl solution and it has a potential use for separation and preconcentration of Hg(2+) ions from contaminated natural waters.
authors.affiliation: Department of Applied Chemistry, Zhejiang Gongshang University, No. 149 Jiaogong Road, Hangzhou City, Zhejiang Province 310012, China. xiongch@163.com
authors.forename: Chunhua
authors.initials: C
authors.lastname: Xiong
authors.forename: Leilei
authors.initials: L
authors.lastname: Pi
authors.forename: Xinyi
authors.initials: X
authors.lastname: Chen
authors.forename: Liqun
authors.initials: L
authors.lastname: Yang
authors.forename: Chunan
authors.initials: C
authors.lastname: Ma
authors.forename: Xuming
authors.initials: X
authors.lastname: Zheng
mesh_terms: D000327:Adsorption; D001562:Benzimidazoles / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry*; D048271:Chitosan / Q000138:chemical synthesis / Q000737:chemistry*; D004811:Epichlorohydrin / Q000737:chemistry; D005504:Food Analysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008628:Mercury / Q000737:chemistry* / Q000302:isolation & purification*; D008863:Microspheres; D012996:Solutions; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D001562:Benzimidazoles; D002614:Chelating Agents; D012996:Solutions; D014874:Water Pollutants, Chemical; D014867:Water; D004811:Epichlorohydrin; D048271:Chitosan; D008628:Mercury
keywords: Adsorption; Chitosan microsphere; Desorption; Hg(2+); Selectivity