Removal of copper ions from aqueous solutions by dried sunflower leaves

In the present work, the potential use of dried sunflower leaves to remove copper ions from aqueous solutions was evaluated. Kinetic data and equilibrium sorption isotherm were measured in batch conditions. The influence of some parameters such as: contact time, initial metal concentration, initial pH of solution and copper salt nature on the metal removal kinetics has been studied. Copper uptake was time contact, initial copper concentration, initial pH solution and copper salt type dependent. The sorption of copper increased as contact time, initial metal concentration, initial pH of solution increased. Maximum copper sorption was found to occur at around initial pH 5-6. Three simplified kinetic models including a first-order equation, pseudo-second-order and second-order equations were selected to follow the sorption process. The process follows a pseudo-second-order kinetics. Langmuir and Freundlich models were used to describe sorption equilibrium data at natural pH of solution. Results indicated that the Langmuir model gave an acceptable fit to the experimental data than the Freundlich equation. Maximum copper uptake obtained was q(m) = 89.37 mg/g (1.41 mmol/g). (c) 2006 Elsevier B.V. All rights reserved.