Facile room temperature synthesis of MIL-100(Fe) from magnetic zircon tailing and its application for methylene blue removal

Some of the dominant minerals found in the magnetic separation of zircon tailing are minerals containing iron (Fe). These materials have the potential to be processed into adsorbents. One of the materials synthesized using iron compounds as a precursor is MIL-100(Fe). The aim of this research was to obtain MIL-100(Fe) by utilizing magnetic zircon tailing, and applied as an adsorbent for methylene blue. The synthesis of MIL-100(Fe) was initiated by destruction of magnetic zircon tailing with HCl, followed by reacting the destruction filtrate with trimesic acid (H3BTC) for 24 hours at room temperature, in which the H3BTC was dissolved in NaOH with a molar ratio of 1.5 Fe: 1 H3BTC: 3 NaOH, prior to the reaction. A reddish orange precipitate obtained was then washed, dried, and characterized by using FTIR, XRD and SEM. Characteristics of FTIR spectra, XRD pattern and SEM images was similar with MIL-100(Fe) reported. The best-fitting model for the adsorption mechanism was the pseudo-second order. The most suitable adsorption isotherm was the Langmuir model. The maximum adsorption capacity of MIL-100(Fe)-W (222.89 mg/g) was higher than that of MIL-100(Fe)-C (151.59 mg/g). The result indicated that iron content in magnetic zircon tailing can be used as precursor for synthesis of MIL-100(Fe).