Eco-friendly polyacrylic acid based porous hydrogel for heavy metal ions adsorption: characterization, adsorption behavior, thermodynamic and reusability studies

Abstract

Hydrogels are the most commonly used 3D polymer mesh materials for environmental removal due to their ability to hold water in their porous structures. In this study, polymeric hydrogels were used for metal removal from wastewater. Polyacrylic acid is an environmentally friendly polymer with known biodegradable and antimicrobial properties. Polyacrylic acid based (PAA) hydrogel were used as an adsorbent for removal of the M2+ (Cd2+, Ni2+ and Cu2+) and Fe3+ ions from aqueous solutions in this study. Eco-friendly functional PAAbased hydrogel was obtained by in-situ free radical polymerization technique. The effect of pH on the swelling characteristic of hydrogel was examined exhaustively and the highest swelling capacity as 1200% was seen for 2% cross-linked PAA hydrogel at pH 10. All these samples gave highly impressive results in the adsorption of Cu2+, Cd2+, Ni2+, and Fe3+ from water solutions at pH values between 2 and 10. The highest adsorption capacity of the metal ions on hydrogel was specified as Cd2+ ion. Due to its clean production process, high heavy-metal adsorption capacity and the re-usability, PAA-based hydrogels have a high potential as an ecofriendly cleaner production material.