Masoumeh Mohammadnejad - Department of Analytical Chemistry, Faculty of Chemistry, Alzahra University, Tehran, Iran
Alieh Moeinipour - Department of Analytical Chemistry, Faculty of Chemistry, Alzahra University, Tehran, Iran

In the present study, HKUST-۱ (Hong Kong University of Science and Technology), HKUST-۱@PVA, and Fe۳O۴@HKUST-۱, 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-۱, Fe۳O۴@HKUST-۱, and HKUST-۱@PVA are based on Langmuir isotherm (the values of qmax were obtained as ۸۸۳.۳۳, ۲.۵۰E+۰۳ mg/g for HKUST-۱@PVA and Fe۳O۴@HKUST-۱, respectively) and Freundlich isotherm (the values of KF were obtained as ۳.۰۲E+۰۳ (n=۰.۷۴), ۷.۲۴E+۰۳ (n=۰.۹۹) and ۷.۹۹E+۰۴ (n=۱.۴۹) for HKUST-۱, Fe۳O۴@HKUST-۱ and HKUST-۱@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-۱ with magnetic nanoparticles decreased the adsorption time, and with PVA provides more functional group on the surface of HKUST-۱ and increases its adsorption efficiency. Further, an easy separation with an external magnet in ۳۰ seconds is another advantage of magnetic functionalization. The aforementioned features make these adsorbents appropriate candidates for cost-effective water treatment.

HKUST-۱ Metal-organic Frameworks, HKUST-۱@PVA, Fe۳O۴@HKUST-۱, Meloxicam, Removal, Nonlinear Langmuir isotherm