Removal of Cu(II) and Pb(II) ions from aqueous solutions by adsorption on sawdust of Meranti wood

Meranti tree sawdust, an inexpensive material, is currently being investigated as an adsorbent for the removal of Cu(II) and Pb(II) ions from aqueous solutions. In this work, adsorption of Cu(II) and Pb(II) ions on Meranti tree sawdust has been studied by using batch techniques. The equilibrium adsorption level was determined to be a function of the solution of pH, contact time, and adsorbent dosage. Adsorption isotherms of Cu(II) and Pb(II) ions on adsorbents were determined and correlated with common isotherm equations such as Langmuir and Freundlich models. The thermodynamic parameters like free energy, enthalpy, and entropy changes for the adsorption of Cu(II) and Pb(II) ions have also been computed and discussed. The heat of adsorption [ΔH = 31.47 kJ/mol for Cu(II) and ΔH = 20.07 kJ/mol for Pb(II)] implied that the adsorption was endothermic in nature.