ADSORPTION OF COPPER AND CADMIUM IONS FROM AQUEOUS SOLUTIONS BY EUCALYPTUS BICOLOR LEAF POWDER

Eucalyptus bicolor Leaf Powder (ELP) has been utilized as a sorbent for uptake Cu(II) and Cd(II) ions from aqueous solution. Equilibrium adsorption experiments were conducted to evaluate the adsorption characteristics of Cu(II) and Cd(II) from aqueous solutions by ELP. The equilibrium sorption isotherms have been analyzed by the linear, Freundlich and Langmuir models. Langmuir isotherm is better fit than the Freundlich isotherm at different temperature according to values of the correlation coefficients (r).. The maximum adsorption capacity (Xm) of ELP for the adsorption of Cu2+ ions and Cd2+ ions decreased from 3.27x10-5 and 3.07x10-5 to 1.19x10-5 and 1.06x10-5 mol/g with increasing temperature from 298 to 313 K. The dimensionless factor, RL revealed the favorable nature of the isotherm of metal ion-ELP system. The negative free energy values indicate the feasibility of the process and the spontaneous nature of the adsorption. negative ∆ H values indicate the exothermic and physical type of the adsorption. A positive entropy of adsorption also reflects the affinity of ELP for Cu (II) and Cd(II) . The PH for all solutions were in the range of 5 to 6. Results showed that the powder could remove the ions effectively from aqueous solution.