Metal-organic framework based on iron doping: Green synthesis and sustainable adsorbent for anionic dye contaminated water

Industrial effluents have emerged as a critical environmental challenge due to limited water resources, their toxic nature, and carcinogenic properties. Therefore, it is essential to treat industrial wastewater and eliminate toxic pollutants. This study focuses on synthesizing nanocrystals of zeolite imidazole frameworks (ZIF-۸) by doping with iron to create a porous ZnFe/ZIF-۸ (ZFZ) composite using a green method (water solvent) to enhance performance and synergistic effects. The morphology of ZFZ nanocrystals was analyzed using a variety of complementary characterization techniques (Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM)). The ZFZ and ZIF-۸ were assessed for the removal of Direct Red ۲۳ (DR-۲۳) dye from wastewater by varying the effective variables (pH, dye dosage, initial concentration, an(d contact time). For comparative analysis, ZIF-۸ was also synthesized and used in conjunction with ZFZ to remove the DR-۲۳ dye. The results demonstrated that ZFZ possesses a significantly higher adsorption capacity (۳۸۳ mg/g) for DR-۲۳ than ZIF-۸ (۹۴.۷۹ mg/g), representing a fourfold enhancement. At a contact time of ۱۲۰ minutes, the ZFZ composite achieved a maximum removal efficiency of ۹۲.۳% with ۰.۰۰۶ g of adsorbent at pH ۳. Analysis of the equilibrium adsorption data for anionic dyes confirmed a strong alignment with the Langmuir model (R² = ۰.۹۹), consistent with a homogeneous, monolayer adsorption process. Additionally, the adsorption mechanism on ZFZ and ZIF-۸ composites followed second-order kinetics with R² = ۰.۹۹. These findings confirm that synthesized ZFZ is an efficient adsorbent for the remediation of dye-contaminated wastewater.

کلیدواژه ها:

Wastewater treatment ، MOF ، Dye Remova ، Direct Red ۲۳ ، Green synthesis