Various treated forms of dead Pleurotus mutilus biomass, chitin and chitosan were used for the removal of Cu(II) ions from aqueous solutions. The biomass was found to be as efficient as chitin and maximum yield was obtained at pH around 6. The yield was increased significantly with respect to the free matter when treatments with 0.2% glutaraldehyde or 5% NaOH were perforned, 23, 42 and 30 mg/g of dry matter respectively being obtained after 60 min equilibrium time. In multi-component solutions containing Cd(II) and Zn(II) the binding capacity toward Cu(II) was reduced. (c) 2006 Elsevier Ltd. All rights reserved.