Development of novel blend membranes based on carbohydrate polymers for the removal of toxic metal ions through sorption

Abstract

The present study describes the development of novel sodium alginate–gelatin (SAG) blend membranes for the removal of copper(II) and nickel(II) ions from aqueous solutions through sorption. The SAG blend membranes were chemically crosslinked by various crosslinkers, such as glutaraldehyde (GA), urea-formaldehyde (UF) and thiourea-formaldehyde (TF) in order to enhance the strength of the membranes and reduce their swelling behaviour in presence of water. The resulting membranes were extensively characterized by FTIR, SEM and DSC to study various structural aspects of the membranes. Equilibrium swelling experiments were performed on SAG membranes in metal ion solutions at 30°C. The effect of contact time, initial pH and initial metal ion concentration on the sorption behaviour of the membranes was investigated. The adsorption capacities of copper(II) and nickel(II) on the SAG (SAG-GA/UF/TF) membranes as obtained from Langmuir adsorption isotherm were found to be 0.4284, 0.5307, 0.6847 mM/g and 1.7567, 3.3329, 4.1 mM/g, respectively.

Keywords:

• Sodium alginate
• Gelatin
• Crosslinking
• Sorption
• Copper
• Nickel

Acknowledgements

Authors gratefully thank the Board of Research in Nuclear Sciences (BRNS), India for financial support for this work (Grant No.: 2010/37C/53BRNS/2538, Dated 23 February 2011).