Removal of Crystal Violet Dye from Aqueous Solutions Using a Xanthan Gum-Based Hydrogel Nanocomposite with TiO2 Nanoparticles as an Eco-Friendly Green Surface

A hydrogel nanocomposite xanthan gum-grafting-poly(acryl amide-itaconic acid-acrylic acid)/TiO2 (XG-g-poly(AAm-IA-AAc)/TiO2 was synthesized using co-polymerization method using the natural polymer xanthan gum (XG) with acrylamide (AAm), acrylic acid (AAc),  and itaconic acid (IA) monomers, incorporating TiO2 nanoparticles onto the polymer matrix using (KPS) as initiator and a crosslinking agent (MBA). The hydrogel nanocomposite proved its high efficiency in removing CV dye from aqueous medium. The best optimal conditions for adsorption were studied, including contact time, adsorbent dosage, pH, ionic strength, and temperature. The data appear that the maximum removal percentage at 99.98% at an equilibrium time 2 h, weight of hydrogel  of 0.03 g, pH solution 5, and temperature of 35 °C. The hydrogel nanocomposite’s structure and morphology were investigated using FESEM, XRD, and FTIR. The results showed that the second-order kinetic model accurately represents the adsorption data. Equilibrium isotherms were studied utilizing Freundlich, Langmuir, and Temkin model, found the adsorption process best fits the Temkin model.