Metal?organic framework material MIL?53(Fe) was added as a modifier to polyvinylidene fluoride (PVDF) casting solution, and PVDF/MIL?53(Fe) composite membrane was fabricated. The composite membranes were characterized by a series of tests, including XRD, FT?IR, SEM and TG. The composite membrane was used as an adsorbent to adsorb Congo red (CR) from aqueous solution. The effects of composite membrane dosage, initial concentration of CR solution, contact time and temperature were discussed, and the isothermal adsorption models, adsorption kinetics, and adsorption thermodynamics were also studied. The results show that the most appropriate dosage of the composite membrane is 20 mg in each experiment. The maximum theoretical adsorption capacity of CR by the composite membrane is 71.9 mg/g at 313 K. Ethanol has good desorption effect on CR adsorbed onto the composite membrane, and the composite membrane can maintain good adsorption capacity after 5 adsorption?desorption cycles. The isotherm data follows the Langmuir isotherm model and the kinetic adsorption follows the pseudo?second?order model. This adsorption process is spontaneous and endothermic, which is illustrated by the thermodynamic data.

Metal organic framework ZIF?67 has been successfully fabricated via solvothermal method. The as?synthesized ZIF?67 was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X?ray powder diffraction and thermogravimetric analysis. The adsorption property of ZIF?67 for methyl orange was investigated. The effects of pH value, dosage of adsorbent, initial concentration of methyl orange solution, contact time and temperature were discussed. The results show that the most proper dosage of ZIF?67 is 20 mg. When the pH value of the dye solution is 7, the adsorption capacity is the best. At 303 K, the adsorption reached an equilibrium within 25 min. The maximum adsorption capacity of ZIF?67 for methyl orange is 152.67 mg/g at 303 K. The isotherm data followed the Langmuir isotherm model and the kinetic adsorption obeyed the pseudo?second?order model. Thermodynamic parameters illustrated that the adsorption process is spontaneous and endothermic. The spent ZIF?67 has excellent regenerative performance by treating with ethanol, and the adsorption ability of ZIF?67 remains good after six adsorption?desorption cycles.