Enhanced removal of phosphate from water by fabricating a novel dual metal MIL-101(Fe/Zr)

Metal-based compounds are promising adsorbents for phosphate.A novel dual metal-organic framework as an effective adsorbent for phosphate was synthesized by a solvothermal method.The structure analysis revealed that the as-prepared adsorbent(denoted as MIL-101(Fe/Zr))possessed a porous polyhedral structure with a large specif-ic surface area of 479.1 m2/g and a pore width of 3.4 nm.The X-ray diffraction pattern and Fourier transform infra-red spectra suggested that the MIL-101(Fe/Zr)shared a similar structure with MIL-101(Fe),implying successful in-corporation of Zr atoms as a second metalinto the MIL-101(Fe)structure.Kinetic adsorption of P043-by MIL-101(Fe/Zr)conformed to the pseudo-second-order model and intraparticle diffusion model,while adsorption isotherm fitted the Freundlich model well(R2=0.978 5).It is suggested that such an adsorption belonged to multiply-layer adsorption.The adsorption capacity of MIL-101(Fe/Zr)was to be 66.00 mg/g.MIL-101(Fe/Zr)performed well at a wide range of pH 2.0～10.0 and high ionic strength(0～40 mg/L NaCl).A structural analysis indicated that the complexation interaction was mainly responsible for PO 4 3 adsorption.These findings can inspire preparation of other dual metal MOFs adsorbent for phosphate removal and recovery from water.