Fabrication of nanotitania/calcium alginate and cupper ferrite/calcium alginate nanocomposite beads: adsorption of methylene blue

In this study five solid adsorbents nanoparticles were synthetized namely: titanium dioxide (NT), calcium alginate (AG), cupper ferrite (CF), cupper ferrite/calcium alginate composite (CG), and titanium dioxide/calcium alginate composite (TG). The fabricated materials were investigated by different tools such as loss on drying, TGA, N₂ adsorption/desorption, XRD, SEM, TEM, pH_PZC, and FTIR. These synthetized materials were used as solid adsorbents for methylene blue adsorption under different conditions. The characterization tools prove that TG nanoparticles is characterized by 361.1 m²/g (specific surface area), 4.51 nm (pore radius), 5.80 (pH_PZC), nearly 90 nm (TEM particle size), and the presence of many polar chemical functional groups. TG showed the maximum Langmuir adsorption capacity at 40 ^oC (448.76 mg/g) with obeying of PFO, Elovich kinetic model, spontaneous, endothermic, and physical adsorption process as reported by kinetic and thermodynamic studies. Adsorption of MB onto all the investigated solid materials follows Freundlich, Temkin, Dubinin-Radushkevich, and Langmuir adsorption models with correlation coefficients > 0.9242. Desorption studies prove that ethanol is the most accepted desorbing solution with 75.46% desorption efficiency.