Recovery of heavy metals from aqueous solution by using radiation crosslinked poly(vinyl alcohol)

Crosslinked poly(vinyl alcohol) (PVA) and PVA/acrylic acid hydrogels, prepared by gamma-irradiation, were used in the removal of heavy metals from aqueous solution. Comparative studies of the properties of the two hydrogels were made. The application of the prepared hydrogels as adsorbent materials for Cu2+, Co2+, and Ni2+ from aqueous solution was studied. The chemical and physical properties of the hydrogels, before and after adsorption of the heavy metal ions, were investigated by means of thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. The efficiency of such hydrogels for the recovery of metal ions was determined by atomic absorption and UV spectroscopic analysis. The effect of changing pH on the metal uptake was also studied. It was found that the prepared hydrogels have a substantial ability to adsorb metal ions from their solution. (C) 2004 Wiley Periodicals, Inc.