Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
581872 | Journal of Hazardous Materials | 2009 | 9 Pages |
Abstract
A series of new chemical-modified lawny grass adsorbents were prepared and the feasibility of absorbents to remove Pb(II) ion from aqueous solution was examined. The absorbents were characterized by FTIR spectra and elemental analysis. Kinetics, equilibrium, thermodynamics, column adsorption and mechanism were studied. The optimum pH is in the range of 5.0-5.8 for all adsorbents. The sorption system follows pseudo-second-order kinetic model and equilibrium time is obtained after 60Â min. The maximum adsorption capacities obtained from Langmuir-Freundlich model are 1.55 and 1.26Â mol/kg by using 1Â CG and 0.6Â CG (lawny grass modified by 1Â mol/L or 0.6Â mol/L citric acid, respectively). Thermodynamic parameters such as ÎG, ÎH and ÎS are evaluated for the adsorption process. The results indicates that the adsorption of Pb(II) is spontaneous and endothermic. The breakthrough point is achieved at 100Â BV (bed volume) by a column of 0.6Â CG. Desorption of Pb(II) and regeneration of the column is achieved by 0.1Â mol/L HCl elution. After 3 adsorption/desorption cycles, the breakthrough point remains around 100Â BV, which shows that grass adsorbent is regenerated easily and used repeatedly. Above results indicates that lawny grass have a good potential for removal of lead from dilute aqueous solution in the future.
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Authors
Dandan Lu, Qilin Cao, Xiuju Cao, Fang Luo,