Synthesis and characterization of novel zinc–organic framework for the effective removal of Alizarin Red S

Water treatment has become a pressing global issue due to the increasing number of pollution sources. Among the major contributors to water contamination is the widespread use of dyes, such as Alizarin Red S, across various industries. In this study, Zn-MOF nanoparticles were prepared using the conventional solvothermal method and characterized through Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope coupled with energy dispersive X-ray spectroscopy (SEM-EDX), Brunauer-Emmett-Teller (BET) analysis as well as thermogravimetric analysis (TGA). The adsorption performance of Zn-MOF nanoparticles for removing Alizarin Red S (ARS) was investigated using batch adsorption experiments. Key parameters, including Zn-MOF dosage, initial ARS concentration, pH and contact time were evaluated under ambient conditions. The results demonstrated an ARS removal efficiency of approximately 71% at pH 4, a Zn-MOF dosage of 1 g/L and a primary ARS concentration of 20 ppm within 40 min. Additionally, the material exhibited reusability for up to three cycles, maintaining a removal efficiency of 60%. Freundlich, Langmuir, and Temkin were three isotherm and kinetic models applied to illustrate the adsorption mechanism. Adsorption was found to align with the Langmuir isotherm model as well as following pseudo-second-order kinetics.