Removal of Copper Ions from Aqueous Solutions by Dried Activated Sludge

In the present work, the usefulness of dried activated sludge has been investigated for the removal of copper ions from aqueous solutions. Kinetic data and equilibrium sorption isotherms were measured in batch conditions. The influence of initial pH, metal concentration 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. Maximum copper sorption was found to occur at around pH 5.5-6.0. Three simplified kinetic models including a pseudo firstorder 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 initial pH of solution. Results indicated that the Langmuir model gave a better fit to the experimental data than the Freundlich equation. Maximum copper uptake obtained was qm = 62.50 mg/g (0.556 mmol/g) at natural pH of solution.