title: Nitrate removal from aqueous solutions by cross-linked chitosan beads conditioned with sodium bisulfate.
abstract: The investigation of adsorption of nitrate onto chitosan beads modified by cross-linking with epichlorohydrin (ECH) and surface conditioning with sodium bisulfate was performed. The results indicated that both cross-linking and conditioning increased adsorption capacity compared to normal chitosan beads. The maximum adsorption capacity was found at a cross-linking ratio of 0.4 and conditioning concentration of 0.1mM NaHSO(4). The maximum adsorption capacity was 104.0 mg g(-1) for the conditioned cross-linked chitosan beads at pH 5, while it was 90.7 mg g(-1) for normal chitosan beads. The Langmuir isotherm model fit the equilibrium data better than the Freundlich model. The mean adsorption energies obtained from the Dubinin-Radushkevich isotherm model for all adsorption systems were in the range of 9.55-9.71 kJ mol(-1), indicating that physical electrostatic force was potentially involved in the adsorption 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*; D003432:Cross-Linking Reagents; D009566:Nitrates / Q000302:isolation & purification*; D055672:Static Electricity; D013431:Sulfates / Q000737:chemistry*; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*
chemical_list: D003432:Cross-Linking Reagents; D009566:Nitrates; D013431:Sulfates; D014874:Water Pollutants, Chemical; C012036:sodium sulfate; D048271:Chitosan