Selective Adsorption of Heavy Metal Cations and Anions from their Aqueous Solution Mixture with Hydrogels

Abstract

Hazardous Ni²⁺ and Cr⁶⁺ ions could be selectively adsorbed from the aqueous solution mixture of nickel chloride and chromium trioxide with hydrogels of Acrylamide/sodium acrylate (PAAm/SA) and acrylamide/N,N-dimethylaminopropylacrylamide (PAAm/DMAPAA), respectively. The order of adsorption procedure with these gels affected adsorption efficiencies, and the adsorption of Ni²⁺ became dominant at intermediate region, while that of Cr⁶⁺ at lower pH region. These results indicate that adsorption of HHM ions could be effectively regulated by changing pH of the solution mixture.