Polyethyleneimine functionalized chitosan nanofiltration membrane for nuclear wastewater decontamination

Decontamination of nuclear wastewater is of vital significance for the sustainable development of nuclear energy. Nanofiltration (NF), with the ability to realize precise ion separation, has attracted great interests in removing nuclides from the wastewater due to its high separation efficiency and easy operation feature. To fabricate NF membrane with high nuclide selectivity and excellent water perm-selectivity, chitosan (CS)-based NF membrane was synthesized in this work via a facile interfacial polymerization (IP) with polyethyleneimine (PEI) postfunctionalization. The introduced PEI provided the NF membrane a strong positive charge density and a larger pore size. Consequently, high water permeance around 17.4 L m-2h- 1 bar-1 and outstanding rejections towards CoCl2, SrCl2 and CsCl (94.8 %, 93.1 % and 32.3 %) were achieved. In comparison with the existing membranes, the CS-based TFC membrane possessed a higher water permeance with a similar nuclide selectivity. Moreover, the newly designed membrane sustained a high stability after treated with acid and base solutions. These features endowed the PEI functionalized chitosan-based NF membrane promising potentials in the decontamination of nuclear wastewater.