Adsorption behavior and mechanism of action of magnetic MIL-100(Fe) on MB

Dye wastewater seriously affects human living environment and human health. This experiment develops green and efficient recyclable Fe3O4@MIL-100(Fe) under room temperature conditions. The microscopic morphology, chemical structure and magnetic properties of Fe3O4@MIL-100 (Fe) were characterized by SEM, FT-IR, XRD and VSM, and the adsorption capacity and adsorption mechanism of the adsorbent on methylene blue (MB) were investigated. The results showed that MIL-100(Fe) was successfully grown on Fe3O4, and the composite had excellent crystalline shape and morphology and good magnetic response. The specific surface area of Fe3O4@MIL-100(Fe) is 1203.18 m(2) g(-1) by N-2 adsorption isothermal curve, and MIL-100(Fe) still has high specific surface area after compounding with magnetic particles. The adsorption process follows the quasi-level kinetic equation and the Langmuir isothermal model, according to which the adsorption capacity of Fe3O4@MIL-100 (Fe) on MB can be up to 487.8 mg g(-1) for a single molecular layer. The thermodynamic experiments show that the adsorption of MB by the adsorbent is a spontaneous heat absorption process. In addition, the adsorption amount of Fe3O4@MIL-100 (Fe) on MB was still maintained at 88.4% after 6 cycles with good reusability, and its crystalline shape did not change significantly, indicating that Fe3O4@MIL-100 (Fe) can be used as an efficient and regenerable adsorbent for the treatment of printing and dyeing wastewater.