Exploration of Adsorption Efficiency Mechanism and Swelling Behavior of Novel Green Itaconic Acid Modified Gellan Gum Hydrogel Nanocomposite for the Removal of Noxious Dyes

Herein, a novel, ecologically sustainable hydrogel nanocomposite (GG-g-ITA/SA/PVA/MMT) was synthesized by incorporating GG-g-ITA with Alginate and Polyvinyl alcohol using MBA as crosslinker and MMT as nanofiller employed for the eradication of Azure B (AB) and Crystal Violet (CV) taken as probe-pollutants from the aquatic medium. The physiochemical facets of GG-g-ITA/SA/PVA/MMT were characterized by Fourier Transmission Infrared spectroscopy, X-ray diffraction, Transmission Electron microscopy, Brunauer-Emmett+Teller, Scanning electron microscopy-energy dispersive X-ray and elemental mapping. The removal efficiency of the hydrogel nanocomposite was meticulously evaluated for isotherm, kinetic, and thermodynamic studies using the batch methodology. Isotherm outcomes concurred with the Langmuir isotherm model with laudable sorption capacities (232.55 mg/g for AB and 454.54 mg/g for CV) while the kinetics findings followed the pseudo-second-order model. Thermodynamics affirmed that the adsorption process was endothermic, feasible, and spontaneous. Van der Waals forces, hydrogen bonds, and electrostatic interactions constituted the potential adsorption mechanism. The adsorbent exhibited a swelling capacity of 96.7% within 60 min and revealed a high potency in recyclability with significant percent removal for both dyes in the fourth cycle. The co-existing ions have a minor influence on the removal efficiency of GG-g-ITA/SA/PVA/MMT. This green hydrogel nanocomposite can be regarded as a potential adsorbent for the mitigation of perilous dyes AB and CV with admirable sorption capacities to achieve a cleaner aquatic environment.