REMOVAL OF ZINC (II) IONS FROM AQUEOUS SOLUTION USING MSASA TREE (BRACHYSTEGIA SPICIFORMIS) LEAF POWDER: EQUILIBRIUM STUDIES

Abstract

The efficiency of using Brachystegia spiciformis leaf powder to remove zinc (II) ions from aqueous solution was studied. The influence of various process parameters like pH, contact time, biomass dose and initial metal ion concentration was investigated using batch experiments.The biosorbent was characterized by infrared spectroscopy and surface area analyzer. The obtained optimum conditions for highest metal uptake was at solution pH 6, contact time of 120 mins and biomass dosage of 2.0 g. The increase in initial zinc ions concentration led to an increase in uptake by the biomass. The equilibrium sorption data for the metal system was modelled and found to fit better to the Langmuir than to the Freundlich isotherm. The Freundlich constant Kf, n value and the correlation coefficient were 0.041 [mg/g(L/mg)n], 1.235 (g/L) and 0.9569 respectively. The Langmuir maximum adsorption capacity Qmax, b and R2 values were found to be 1.85 mg/g, 0.0152 L/g and 0.9902 respectively.