Amaku F. J. and Onwu F. K.
The biosorption of single metal system of Cr(III) and binary metal systems (Cr-Pb, Cr-Cd and Cr-Ni) from aqueous solutions using Luffa cylindrica fibre biomass was investigated as a function of biomass dose and contact time. Results showed that maximum adsorption of single Cr(III) ions was obtained at biomass dosage of 500 mg/L. In the binary solutions of Cr(III)-Cd(II), 63.45% of Cd(II) and 66.5% of Cr(III) were adsorbed at a biomass dosage of 1100 mg/L. At 300 mg/L dosage, 70.70% of Cr(III) and 94.27% of Pb(II) were obtained as the maximum metal-ion adsorbed in the binary metal systems of Cr-Pb. The optimum biomass dosage of Cr-Ni binary system was found to be 900 mg/L. All the optimum dosages obtained were used for kinetic experiment on both the single and binary mixtures. Studies on the effect of contact time on the adsorption of the metal ions were used to access the kinetics of the adsorption process. Both pseudo-first order and pseudo-second order kinetic models were applied to the experimental adsorption data and results showed that the biosorption process for the systems studied followed pseudo-second order kinetics
