Removal of copper(II) from aqueous solutions by chitosan adsorption

An investigation on the use of chitosan for the removal of copper from aqueous solutions has been carried out. Both kinetic data and equilibrium isotherms were obtained. The effects of contact time, initial copper concentration, background electrolyte, and pH on the uptake capacity of copper were studied. Initial copper concentration and pH were found to have the greatest effects on uptake. The copper uptake of chitosan was quantitatively evaluated using sorption isotherms. Results indicated a capacity of 1.8-2.2 mmol/g of dry mass. The capacity increases when solutions contain high concentrations of chloride ions. The variation of pH leads to competition between coordination of copper with chitosan with the optimal range being 5.4 to 6.0.