Metal organic frameworks MIL-100(Fe) as an efficient adsorptive material for phosphate management

Abstract The excessive discharge of phosphate in water bodies is one of the primary factors causing eutrophication. Therefore, its removal is of significant research interest. The present study deals with the development and performance of highly effective phosphate-adsorbent. Here, we have synthesized MIL-100(Fe) metal-organic frameworks as a facile strategy to effectively remove phosphate from eutropic water samples. The adsorbent was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric (TGA) analysis, Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and Wavelength Dispersive X-ray fluorescence (WDXRF). The phosphate adsorption behaviour of MIL-100(Fe) was evaluated with the help of different batch experiments relating to the effect of adsorbent/adsorbate concentration and the solution pH. The MOF offered a maximum adsorption capacity of 93.6 mg.g -1 for phosphate from aqueous solutions with Langmuir isotherm model (R 2 =0.99). MIL-100(Fe) offered an absolute phosphate adsorption performance with a partition co-efficient of 15.98 mg.g -1 .µM -1 at pH 4 and room temperature conditions. Final experiments with real water samples were also carried out to examine the effectiveness of MIL-100(Fe) for phosphate absorption even in the presence of other co-existing ions. These findings support the potential utility of MIL-100(Fe) as nanoadsorbent in phosphate removal for water management.