title: Adsorption of basic dye from aqueous solution onto fly ash.
abstract: The fly ash treated by H2SO4 was used as a low-cost adsorbent for the removal of a typical dye, methylene blue, from aqueous solution. An increase in the specific surface area and dye-adsorption capacity was observed after the acid treatment. The adsorption isotherm and kinetics of the treated fly ash were studied. The experimental results were fitted using Langmuir and Freundlich isotherms. It shows that the Freundlich isotherm is better in describing the adsorption process. Two kinetic models, pseudo-first order and pseudo-second order, were employed to analyze the kinetic data. It was found that the pseudo-second-order model is the better choice to describe the adsorption behavior. The thermodynamic study reveals that the enthalpy (delta H0) value is positive (5.63 kJ/mol), suggesting an endothermic nature of the adsorption.
authors.affiliation: College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310027, PR China; College of Materials and Chemical Engineering, Zhejiang University, Hangzhou 310027, PR China.
authors.forename: J X
authors.initials: JX
authors.lastname: Lin
authors.forename: S L
authors.initials: SL
authors.lastname: Zhan
authors.forename: M H
authors.initials: MH
authors.lastname: Fang
authors.forename: X Q
authors.initials: XQ
authors.lastname: Qian
authors.forename: H
authors.initials: H
authors.lastname: Yang
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D060729:Coal Ash; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry*; D052638:Particulate Matter / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry*; D013816:Thermodynamics; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D060729:Coal Ash; D052638:Particulate Matter; D013464:Sulfuric Acids; D014874:Water Pollutants, Chemical; D002244:Carbon; C033158:sulfuric acid; D008751:Methylene Blue