Kinetic and Equilibrium Adsorption Studies of Pb and Zn ions from Aqueous Solution onto Plantain Stalk ( Musa Paradisiaca )

摘要

This study presents the sorption of Pb2+ and Zn2+ from aqueous solution by Musa Paradisiaca (plantainstalk) with respect to its equilibrium and kinetic behaviour. The optimum pH was found to be 5.0 and 6.0 for the sorptionof the Pb (II) and Zn (II) ions respectively. At pH 5.0, the biomass sorbed 91.7% Pb(II) and 89.85% Zn(II), while at pH6.0, the biomass sorbed 91.16% Pb (II) and 89.55% Zn (II). The contact time for the sorption was found to be rapid in thefirst 5mins. The amount of metal ion sorbed was found to be rapid from the lowest concentration, 10 mg/L to the highestconcentration, 500 mg/L. The Langmuir and Freundlich model for dynamic metal ion uptake proposed were well fittedfor Pb2+ and not well fitted for Zn2+. The structural groups of the adsorbent were characterized by Fourier transforminfrared (FTIR) Spectrometry. The following were present; hydroxyl, carbonyl, amine and phosphate groups whichconfirms the potential processes of sorption of the biosorbent. The first order and second order rate equation were testedand it was found that pseudo-second-order is more suitable for the sorption, having the linear coefficient of determinationR2 value of 0.999. The result obtained from this study indicated that plantain stalk (Musa Paradisiaca) could be employedfor the removal of heavy metal contaminants from industrial effluents.