Enhanced Recovery of Pb2+ Ions from Aquatic Media by Using Polyurethane Composite as Adsorbent

Abstract

Elastomeric polyurethane (PU) and its composites (PUN and PUC) with different types of filler were prepared and investigated by differential analysis. Their ability to remove Pb2+ ions from aqueous solutions was studied. The results indicated that, at high concentration of Pb2+ ions (500 mg/L), the removal efficiency of Pb2+ ions by PUC is better than PUN; at low concentration of Pb2+ ions (125 mg/L), the difference in removals between the two is only slight, i.e., 58.36 % by PUC (0.5 g/L) and 55.11 % by PUN (0.5 g/L). Moreover, PUN exhibited a well-developed site structure, providing adsorption sites for Pb2+ ions; for this and for cost reasons, we decided to study Pb2+ ions removal ability of PUN. The results showed that the maximum adsorption capacity of Pb2+ ions at 125 mg/L concentration at pH 5.0, when using 0.5 g/L of PUN as adsorbent, was 142.85 mg/g. Furthermore, the equilibrium data showed that the adsorption of Pb2+ ions on PUN obeys a pseudo-second order kinetic model, depending on adsorbent dosage, pH, initial concentration of metal ions and contact time. From these results, it is suggested that PUN adsorbent may be appropriate for the removal of Pb2+ ions from wastewater.