title: Adsorption performance and mechanism in binding of Reactive Red 4 by coke waste.
abstract: The protonated coke waste was used as a new type of adsorbent for the removal of Reactive Red 4. To identify the binding sites in the protonated coke waste, the waste was potentiometrically titrated. As a result, four types of functional groups were present in the waste, which was confirmed by FT-IR analysis. Among functional groups, primary amine groups (-NH2) were likely the binding sites for anionic Reactive Red 4. It was also found that sulfonate, carboxyl and phosphonate groups played a role in electrostatic interference with the binding of dye molecules. The maximum adsorption capacities of the coke waste were 70.3+/-11.1 and 24.9+/-1.8 mg/g at pH 1 and 2, respectively. Kinetic study showed a pseudo-first-order rate of adsorption with respect to the solution. The uptake of Reactive Red 4 was not significantly affected by the high concentration of salts. These results of adsorption performance indicate the coke waste as a potentially economical adsorbent for dye removal.
authors.affiliation: Division of Environmental and Chemical Engineering, Chonbuk National University, Chonbuk 561-756, Republic of Korea.
authors.forename: Sung Wook
authors.initials: SW
authors.lastname: Won
authors.forename: Guiping
authors.initials: G
authors.lastname: Wu
authors.forename: Hui
authors.initials: H
authors.lastname: Ma
authors.forename: Qiong
authors.initials: Q
authors.lastname: Liu
authors.forename: Yao
authors.initials: Y
authors.lastname: Yan
authors.forename: Longzhe
authors.initials: L
authors.lastname: Cui
authors.forename: Chengfu
authors.initials: C
authors.lastname: Liu
authors.forename: Yeoung-Sang
authors.initials: YS
authors.lastname: Yun
mesh_terms: D000327:Adsorption; D003077:Coke; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D009282:Naphthalenesulfonates / Q000378:metabolism*; D011199:Potentiometry; D012965:Sodium Chloride / Q000494:pharmacology; D017550:Spectroscopy, Fourier Transform Infrared; D013783:Textile Industry; D014227:Triazines / Q000378:metabolism*
chemical_list: D003077:Coke; D007220:Industrial Waste; D009282:Naphthalenesulfonates; D014227:Triazines; D012965:Sodium Chloride