Abstrato

Kinetic, thermodynamic and isothermal parameters of biosorption of Cr (VI) and Pb (II) ions from aqueous solution by biosorbent prepared from corncob biomass

Adeogun A.Idowu, Andrew E.Ofudje, Idowu M.Abidemi, Ahmed S.Akinyeye

The kinetics, equilibrium and thermodynamic of the biosorption of Cr (VI) and Pb (II) ions onto corncob from aqueous solution were investigated. Optimumexperimental parameters were determined to be pH 5.8 for Pb (II) and pH 2.0 for Cr (VI), contact time of 80 min, and temperature 25 C. The maximum biosorption capacity of the biomass was found to be 8.07 mg g-1 for Cr (VI) and 9.05 mg g-1 for Pb (II). Upon treatment with oxalic acid, the values ofmaximumbiosorption capacity for Cr (VI) and Pb (II) were found to be 10.74 and 10.27 mg g-1 respectively. The kinetic studies showed that the biosorption process of the metal ions fitted well with second order model. The calculated thermodynamic parameters (G, H and S) showed that the biosorption of Cr (VI) and Pb (II) ions onto corncob biomass is feasible, spontaneous and exothermic in nature.