Adsorptive Removal of Simazine Using UiO-66@Al₂O₃/Activated Carbon Nanocomposites

A novel UiO-66@Al₂O₃/Activated Carbon nanocomposite was synthesized and evaluated for the removal of simazine from aqueous solutions. Structural and physicochemical characterization of the prepared nanocomposite was performed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and energy-dispersive spectroscopy (EDS), confirming the successful integration of UiO-66, Al₂O₃, and activated carbon within a porous ternary structure. The nanocomposite combines the high surface area of activated carbon, the structural stability of Al₂O₃, and the selective adsorption capability of UiO-66. Adsorption experiments demonstrated that the optimal conditions for simazine removal were pH 7, an adsorbent dosage of 0.5 g L⁻¹, and a contact time of 60 min. The adsorption kinetics followed the pseudo-second-order model (R² = 0.998), while equilibrium data were best described by the Langmuir isotherm model (R² > 0.99), indicating monolayer adsorption on a homogeneous surface. The removal of simazine by the UiO-66@Al₂O₃/Activated Carbon nanocomposite is primarily governed by adsorption mechanisms, including electrostatic interactions, π–π stacking between the aromatic rings of simazine and the organic linkers of UiO-66, hydrogen bonding with surface hydroxyl groups, and diffusion of molecules into the porous structure of the nanocomposite. In addition, the material maintained high removal efficiency after six regeneration cycles, demonstrating excellent stability and reusability. These results suggest that the UiO-66@Al₂O₃/Activated Carbon nanocomposite is a promising adsorbent for the efficient removal of simazine and other organic pollutants from contaminated water.