Post-modification of magnetic metal-organic frameworks with β-cyclodextrin for efficient removal of fungicides from environmental water
Environmental water is contaminated by pesticides, especially fungicides, is a persistent problem worldwide with grave public health consequences. Exiting fungicides removal methods often cannot address the problem quickly and economically. In the current work, a novel β-cyclodextrin modified Fe3O4@MIL-100(Fe) composite (Fe3O4@MIL-100(Fe)/β-CD) was synthesized and utilized as an adsorbent for the removal of fungicides from environmental water. Characterization of the adsorbent revealed that β-CD has been successfully tethered to the shell of Fe3O4@MIL-100(Fe) via tetrafluoroterephthalonitrile as a cross-linker. The main parameters which could affect the adsorption efficiencies were investigated such as adsorbent amount, solution pH value, adsorption equilibrium time, and ionic strength. The adsorption performance of Fe3O4@MIL-100(Fe)/β-CD was assessed, and the β-CD modified surface exhibited high adsorption capacity of triazole fungicides. Moreover, the regeneration of the adsorbent was explored through 5 successive cycles, and results indicated excellent stability. Finally, the proposed material has been successfully applied to the removal of four fungicides in real environmental water samples, and adsorption efficiencies were ranged from 64.52 to 102.10 mg g-1. Compared with other materials, Fe3O4@MIL-100(Fe)/β-CD displayed outstanding adsorption capacity, short adsorption equilibrium time, and could offer a new platform for the removal of trace triazole fungicides in complicated matrices.