In situ assembly of PB/SiO2 composite PVDF membrane for selective removal of trace radiocesium from aqueous environment

A non-toxic and applicable surface-modified polyvinylidene fluoride (PVDF) membrane consisting of Prussian blue (PB) and aminating silica (A-SiO2) nanoparticles was fabricated for the selective removal of trace radionuclide cesium (Cs) from water. The modified membrane denoted as PB/A-SiO2/PVDF exhibited high selective removal of cesium with a high permeate flux of more than 800 L/h.bar.m(2) in a wide pH range from 3 to 9. The adsorption experiments showed that the Langmuir isotherm model and the pseudo-second order model fitted well with the experimental results. The maximum adsorption capacity was 10.95 mg-Cs/g-membrane (i.e. 78.21 mg-Cs/g-PB sorbent on membrane) for the membrane at an initial Cs concentration of 50 mg/L. Based on the high Cs adsorption capacity of PB, the membrane could remove more than 97.5% Cs in the presence of the coexisting ions and organic matter for more than 10 h. The filtrated membrane could be effectively regenerated by NH4Cl, H2O2 and HNO3 solution with negligible decrease in removal efficiency after repeated use. With the high membrane flux and selective removal efficiency, the fabricated membrane can be potentially applied in Cs contaminated water treatment.