Engineering a High-Selectivity PVDF Hollow-Fiber Membrane for Cesium Removal

In this study, a copper ferrocyanide/silica/polyvinylidene fluoride (CuFC/SiO 2 /PVDF) hollow-fiber composite membrane was successfully synthesized through a facile and effective crosslinking strategy. The PVDF hollow-fiber membrane with embedded SiO 2 was used to fix the dispersion of CuFC nanoparticles for cesium (Cs) removal. The surface morphology and chemical composition of the composite membrane were analyzed using scanning electron microscopy and X-ray photoelectron spectroscopy (XPS). The composite membrane showed a high Cs rejection rate and membrane flux at the three layers of CuFC and 0.5% SiO 2 , and its Cs rejection rate was not affected by variation in the pH (pH = 4–10). The modified membrane could be effectively regenerated many times using ammonium nitrate (NH 4 NO 3 ). The Cs selectivity performance was verified by an efficient Cs rejection rate (76.25% and 88.67% in 8 h) in a solution of 100 μg·L −1 of Cs with 1 mmol·L −1 of competing cations (K + and Na + ). The CuFC/SiO 2 /PVDF hollow-fiber composite membrane showed a particularly superior removal performance (greater than 90%) in natural surface water and simulated water with a low Cs concentration. Therefore, the CuFC/SiO 2 /PVDF hollow-fiber composite membrane can be used directly in engineering applications for the remediation of radioactive Cs-contaminated water.