Document Type : Research Paper
Department of Analytical Chemistry, Faculty of Chemistry, Alzahra University, Tehran, Iran
In the present study, HKUST-1 (Hong Kong University of Science and Technology), HKUST-1@PVA, and Fe3O4@HKUST-1, metal-organic framework, were synthesized by hydrothermal, post-synthetic modification and pre-synthetic modification methods, respectively. These sorbents were applied to remove the meloxicam drug as the model drug from aqueous solutions. The adsorption isotherm, kinetic, and thermodynamic experiments were done and confirmed that the adsorption behaviors of HKUST-1, Fe3O4@HKUST-1, and HKUST-1@PVA are based on Langmuir isotherm (the values of qmax were obtained as 883.33, 2.50E+03 mg/g for HKUST-1@PVA and Fe3O4@HKUST-1, respectively) and Freundlich isotherm (the values of KF were obtained as 3.02E+03 (n=0.74), 7.24E+03 (n=0.99) and 7.99E+04 (n=1.49) for HKUST-1, Fe3O4@HKUST-1 and HKUST-1@PVA, respectively), with an endothermic mechanism and enthalpy-driven process. The kinetic results showed well-fitting with the pseudo-second-order kinetic model for all of them. The speed of the adsorption process, low cost, high efficiency, and high surface area are the main advantages of the proposed compounds as sorbents. The functionalization of HKUST-1 with magnetic nanoparticles decreased the adsorption time, and with PVA provides more functional group on the surface of HKUST-1 and increases its adsorption efficiency. Further, an easy separation with an external magnet in 30 seconds is another advantage of magnetic functionalization. The aforementioned features make these adsorbents appropriate candidates for cost-effective water treatment.