Superabsorbent hydrogel based on modified polysaccharide for removal of Pb²⁺ and Cu²⁺ from water with excellent performance

Abstract

Abstract This contribution describes the absorption percentage of Pb 2+ and Cu 2+ from water by a superabsorbent hydrogel matrix (SH) made from an anionic polysaccharide copolymerized with acrylic acid (AAc) and acrylamide (AAm). Metal‐absorption tests, upon sequential pH variation, indicated that the SH has pH‐sensitivity for the absorption of both metals from solution, attributed to the functional ionic groups (COOH) present in the AAc and arabic gum (AG) segments. At the pH 5.0, the SH exhibited good absorption capacity: 73.10% for Pb 2+ , 81.99% for Cu 2+ in water and 63.64% for Pb 2+ , and 76.67% for Cu 2+ in saline water with 0.1 mol kg −1 ionic strength. A replicated 2 2 full factorial design with a central point was built to evaluate the maximum absorption capacity of the metals into the SH. It was found that both the interaction and main effects of the pH and the initial concentration of metal solution on absorption percentage of the metals were statistically significant. Surface response plots indicated that the absorption capacity of both metals into the SH may be appreciably improved by using the solutions with lower initial concentration of metal and with higher pH values. Metal‐absorption results demonstrated that the SH is a convenient material for absorption of Pb 2+ and Cu 2+ from pure aqueous and saline aqueous environments. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007