Optimized polyacrylic acid/guar gum/Titanium dioxide (PAA/GG/TiO2) hydrogels were fabricated according to Design-Expert software. The intermolecular structures of the hydrogels and the presence of nanoparticles were examined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). To achieve dye absorption rate, kinetic models such as pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion (Weber-Morris), had been investigated in visible light and UV radiation at an initial concentration of MB 20 (ppm) for one day. Diagrams of absorption isotherms in visible light and UV irradiation at 20-60 (ppm) concentrations were evaluated based on the models of Freundlich, Langmuir (Hanes-Woolf), Temkin, and Dubinin-Radushkevic. The hydrogel containing crosslinker (4 mol %), TiO2 (5 wt %), guar gum (2 wt %), and into the alkaline medium (pH=8) was selected as superlative optimal status. The sample was examined for mapping of x-ray energy diffraction (EDS) according to different elements densities of various circumstances to show the degradation or absorption of methylene blue. The results showed that the prepared hydrogels have a good efficiency for removing cationic contaminants from the aqueous medium and this property is intensified by UV radiation.
