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

• Published in: Microchemical journal 2021-09, Vol.168, p.106357, Article 106357
• Main Authors: Gokmen, F.O., Yaman, E., Temel, S.
• Format: Article
• Language: English
• Subjects: Adsorption; Heavy metal ions; Poly (acrylic acid) hydrogel; Re-usability; Swelling behaviour; Waste-water treatment
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2021.106357

•Using environmentally friendly materials as a cleaning product.•Super adsorbents open a new era in adsorption of heavy metal ions.•Physicochemical behavior of hydrogels in heavy metal adsorption is effective in the adsorption process.•To benefit from adsorption process due to the superior properties of hydrogels in response to stimuli. 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 PAA-based 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 eco-friendly cleaner production material.