The use of eucalyptus leaves as adsorbent for copper ion removal

The possibility of using eucalyptus leaves as a locally available adsorbent for the removal of copper ions from aqueous solutions was studied. A series of batch experiments were carried out at different operating conditions. The influence of initial concentration, adsorbent concentration, contact time, temperature, pH, and presence of other ions such as Na+ and K+ on the adsorption process were investigated. Adsorptions of metal ions were pH dependent and the optimum pH for the removal of Cu2+ was found to be 6.5. The adsorption capacity of copper from aqueous solution by eucalyptus leaves was increased by increasing the contact time. At initial concentration of 100 mg/l, the maximum adsorption capacity was 1.16 mg of copper ion per gram of adsorbent. Isotherm studies showed that the data were best fitted to Langmuir isotherm model. The monolayer adsorption capacity was 1.92 mg/g. The values of R-L and n have indicated the favorability of copper adsorption onto eucalyptus leaves. The results reveal that the adsorption process was spontaneous and exothermic process. Physical activation of eucalyptus leaves influenced the copper removal positively. Addition of salts to the metal solution affected the copper uptake negatively.