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

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 Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and wavelength dispersive X-ray fluorescence (WDXRF). The phosphate adsorption performance of MIL-100(Fe) was evaluated with the help of different batch experiments relating to the effect of adsorbent/adsorbate concentrations 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) mu M-1 at pH 4 and room temperature conditions. Final experiments with real water samples were also performed to examine the effectiveness of MIL-100(Fe) for phosphate adsorption even in the presence of other ions. These findings support the potential utility of MIL-100(Fe) as nanoadsorbent in phosphate removal for water management.This research was performed in part in the Nebraska Nanoscale Facility: National Nanotechnology Coordinated Infrastructure and the Nebraska Center for Materials and Nanoscience, which was supported by the National Science Foundation under Award NNCI-1542182, and the Nebraska Research Initiative. Sandeep Kumar thanks DST, Govt of India, University of Nebraska (UNL) Lincoln, the Daugherty Water for Food Institute (DWFI), and Indo-US Science and Technology Forum (IUSSTF) for financial support through Water Advanced Research and Innovation (WARI) research grant vide letter no. IUSSTF/WARI/2018/F-029-2018 dated 03-01-2018 along with HSCST, Govt of Haryana, India (research grant vide letter No. HSCST/R&D/2018/2103 dated 01-08-2018) and DST-PURSE sanctioned to GJUS&T, Hisar under PURSE program no. SR/PURSE Phase 2/40(G). KHK acknowledges support made in part by a grant from the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, & Future Planning (No. 2016R1E1A1A01940995)