Microwave-Assisted Fabrication of a pH/Salt Responsive Hydrogel from the Micro-CMC, In Situ Polymerized Acrylamide, and Nanoγ-Fe2O3–SO3H Cross-Linked by a Phenyl Bisamide Linker for Pb2+ and Hg2+ Removal

• Published in: Journal of polymers and the environment Vol. 31; no. 2; pp. 461 - 478
• Main Authors: Tamaddon, Fatemeh, Ahmadi-AhmadAbadi, Ehsan
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.02.2023; Springer Nature B.V
• Subjects: Acrylamide; Adsorbents; Adsorption; Biopolymers; Calcium ions; Cellulose; Chelation; Chemistry; Chemistry and Materials Science; Crosslinking; Electrostatic properties; Environmental Chemistry; Environmental Engineering/Biotechnology; Fabrication; Ferric oxide; Heavy metals; Hydrogels; Hydrogen bonding; Industrial Chemistry/Chemical Engineering; Industrial wastewater; Industrial wastewater treatment; Iron; Lead; Materials Science; Mercury (metal); Metal ions; Nanocomposites; Organic solvents; Original Paper; pH effects; Polymer Sciences; Polymerization; Saline solutions; Salts; Solvents; Swelling; Pb; Swelling; Magnetic hydrogel; MicroCMC; Aromatic bis-acrylamide; Microwave-assisted; and Hg; adsorption removal
• ISSN: 1566-2543; 1572-8919
• DOI: 10.1007/s10924-022-02616-w

Conversion of the renewable biopolymers to magnetic adsorbents is a sustainable approach for environmental concerns. Herein, the microwave-assisted micro-carboxymethylated cellulose (MCMC) with DS = 0.76, the in situ polymerized acrylamide, and nano g-Fe 2 O 3 –SO 3 H were fabricated in a three-dimensional hydrogel network by one-pot radical polymerization with an aromatic bis-amide cross-linker. This SO 3 H/phenyl implanted various methods characterized nano-composite hydrogel as a granular porous network with excellent swelling performance for the adsorption of heavy metal ions (HMIs). The results of the influences of pH, organic solvent, and salt onto the hydrogel swelling capacity (SC) showed an increase by raising the pH, a decrease in organic solvents, and a decrease in chloride salt solutions by order of Na +  < Ca 2+  < Fe 3+ . The mechanism and kinetics of hydrogel swelling with a capacity of 60.7 g/g were consistent with the non-Fickian diffusion and Schott's second-order kinetic models. As an adsorbent, the hydrogel removed Pb 2+ and Hg 2+ with an adsorption capacity 91.12 mg/g and 79.64 mg/g at neutral pH 7. The adsorption isotherms of hydrogel for Pb 2+ and Hg 2+ were adequately fitted with the Langmuir model (R 2  = 0.99). The chelation of carboxylate groups to HMIs, electrostatic interactions between the charged surface groups and HMIs, and hydrogen bonding are significant parameters of the adsorption mechanism. The successive adsorption/desorption cycles for HMIs removal offer high potential of this hydrogel for the treatment of industrial wastewaters.