RESUMEN
In the present study, semi-interpenetrating polymer networks (semi-IPNs) were synthesized based on xanthan gum (XG)-cl-2-(N-morpholinoethyl methacrylate) (MEMA)/titanium dioxide (TiO2) in the presence of N, N` methylene bisacrylamide (MBAAm), as the cross-linking agent. After that, the semi-IPN hydrogel was used to adsorb Methylene Blue (MB+) and Crystal Violet (CV+) from single and two-component adsorption systems. The optimal pH for efficient dye adsorption in aqueous solutions has been determined to be 8 for CV+ and 11 for MB+, respectively. The presence of polar oxygen-containing functional groups such as OH, CO, C-O-C, COOH, and others has been noticed to be the primary driving force in dye adsorption. Equilibrium data from a single process fitted very well to the Freundlich and Dubinin-Radushkevich models (R2 = 0.997 and 0.99) for MB+ and CV+, respectively. In a binary system, CV+ removed more than MB+, and both dyes demonstrated synergism during the adsorption of CV+/MB+ solutions. The dye removal efficiency of the adsorbent was found to be quite good even after the fourth adsorption-desorption cycle. In the treatment of multi-component contaminated water, XG-cl-poly (MEMA)/TiO2 might be a beneficial and reusable adsorbent.