Efficient removal of Cs(I) from water using a novel Prussian blue and graphene oxide modified PVDF membrane:...

The Prussian blue (PB) blending membranes are promising candidates for the removal of trace radionuclide Cs⁺. Constructing a membrane with high flux and selectivity are challenging in its practical application. Here, a novel polyvinylidene fluoride (PVDF)-PB-graphene oxide (GO) modified membrane was fabricated via phase inversion for trace radionuclide cesium (¹³⁷Cs) removal from water. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were used to analyze chemical composition and morphology of the membrane, and the properties in terms of water flux and Cs⁺ removal were studied under different PB dosage, pH and co-existing ions conditions. It was observed that the addition of GO improved the dispersion of PB, and the PVDF-PB-GO membrane presented the highest Cs⁺ removal efficiency (99.6 %) and water flux (1638.2 LMH/bar) at pH = 7 with 0.1 wt% GO and 5 wt% PB. In addition, Langmuir and pseudo-second-order kinetics models fitted well for Cs⁺ adsorption by the PVDF-PB-GO membrane, illustrating that the Cs⁺ was removed via chemical adsorption dominated by Fe(CN)₆^4- defect sites of PB and the oxygen groups of GO. Furthermore, the membrane showed a significant selectivity and reusability towards trace radioactive cesium, even in the presence of excess co-existing ions and in real water, which strongly verified that the modified membrane had application potential.