title: Enhanced adsorption of congo red from aqueous solutions by chitosan hydrogel beads impregnated with cetyl trimethyl ammonium bromide.
abstract: The adsorption of congo red (CR) onto chitosan (CS) beads impregnated by a cationic surfactant (CTAB, cetyl trimethyl ammonium bromide) was investigated. Chitosan beads impregnated at a ratio of 1/20 of CTAB to CS (0.05% of CTAB and 1% of CS) increased the CR adsorption capacity by 2.2 times from 162.3 mg/g (0% CTAB) to 352.5 mg/g (0.05% CTAB). The CR adsorption decreased with an increase in pH of the CR solution from 4.0 to 9.0. The Sips isotherm model showed a good fit with the equilibrium experimental data and the values of the heterogeneity factor (n) indicated heterogeneous adsorption of CR onto CS/CTAB beads, as well as CS beads. The kinetic data showed better fit to the pseudo second-order rate model than to the pseudo first-order rate model. The impregnation of CS beads by cationic surfactants showed the highest adsorption capacities of CR compared to any other adsorbents and would be a good method to increase adsorption efficiency for the removal of anionic dyes in a wastewater treatment process.
authors.affiliation: Department of Chemical Engineering, Hanbat National University, San 16-1, Deokmyeong-Dong, Yuseong-Gu, Daejeon 305-719, Republic of Korea.
authors.forename: Sudipta
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Dae S
authors.initials: DS
authors.lastname: Lee
authors.forename: Min W
authors.initials: MW
authors.lastname: Lee
authors.forename: Seung H
authors.initials: SH
authors.lastname: Woo
mesh_terms: D000327:Adsorption; D048271:Chitosan / Q000737:chemistry*; D003198:Computer Simulation; D003224:Congo Red / Q000737:chemistry / Q000302:isolation & purification*; D005374:Filtration / Q000379:methods; D020100:Hydrogels / Q000737:chemistry; D008863:Microspheres; D008956:Models, Chemical; D012996:Solutions; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D020100:Hydrogels; D012996:Solutions; D014874:Water Pollutants, Chemical; D014867:Water; D003224:Congo Red; D048271:Chitosan