ABSTRACT
The research titled Development of Eucalpytus tereticornis composite for chromium (VI) and lead (II) ions adsorption from simulated wastewater was aimed to establish the efficacy of Eucalpytus tereticornis composite as an adsorbent applied in the adsorption of Cr6+ and Pb2+ ions from simulated solution of respective ions. The adsorbent was pretreated with 0.5M of Nitric acid to remove the adsorbent colouration and soluble organic compound. Characterization of the adsorbent was done by the application of Fourier transform infrared (FTIR) and Scanning electronic microscopy (SEM) to determine the functional group and morphology of the adsorbent respectively. Model was developed using RSM to study the interactive effect of contact time and adsorbent dosage on the response (adsorption capacity).batch adsorption test was carried on simulated solution using barks, leaves and composite.it was revealed that adsorption capacity barks on Cr6+ was in the range of 0.80 mg/g to 21.6mg/g. The result on Pb2+ was 2.29 mg/g to 54.05mg/g. The leaves adsorbent showed adsorption capacity for Cr6+ in the range of 0.99mg/g to 28.6mg/g and that of Pb2+ was in the range of 4.330mg/g to 40.65mg/g.The barks to leaves composite ratio in the range of (0.1-0.9) showed the adsortption capacity of Cr6+ in the range of 6.00mg/gto 100mg/g ,while for Pb2+ was in the range of 1.01mg/g to 26.2mg/g. It was revealed that barks to leaves ratio of 0.7 g/g was capable of adsorbing 100mg/g and 26.2 mg/g for Cr6+ and Pb2+ respectively from simulated solution of 100mg/l within the experimental error. Finally, equilibrium data for the adsorption of chromium (VI) and lead (II) ions on Eucalyptus tereticornis composite were tested with various adsorption isotherm models such as Langmuir, Freundlich and Temkin with their generalized equation. The Langmuir isotherm model described the adsorption data best with the highest correlation values R2= 0.9987 for chromium (VI) and R2 0.9793 for lead (II) ions. Different kinetic models such as Pseudo second order, Second order and Elovichnetic model were used to evaluate the mechanism of adsorption of chromium (VI) and lead (II) ions. The kinetics of adsorption of chromium on ETC was well described by the Pseudo-second-order kinetic model with correlation value R2 =0.9961 and that of lead (II) ion followed Elovich kinetic model with highest correlation value R2 = 0.8914