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The application of polyethylenimine grafting reverse osmosis membrane in treating boron‐containing low‐level radioactive wastewaters
Author(s) -
Chen Boxian,
Chen Ding,
Zhao Xuan
Publication year - 2020
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.6291
Subject(s) - polyethylenimine , membrane , reverse osmosis , boron , nuclide , grafting , chemistry , nuclear chemistry , zeta potential , chromatography , chemical engineering , materials science , nanotechnology , organic chemistry , polymer , transfection , biochemistry , physics , quantum mechanics , nanoparticle , engineering , gene
BACKGROUND Reverse osmosis (RO), which is widely utilized in wastewater treatment, has been proven to be an effective tool for ion separation with high salts rejection. However, owing to the extremely low concentration of nuclides in boron‐containing low‐level radioactive wastewaters (LRWs), there is a significant reduction in rejection of nuclides by using commercial RO membranes. In this study, in order to obtain higher nuclides rejection under trace‐level condition, novel polyamide RO membranes were fabricated by grafting polyethylenimine (PEI) with different molecular weights on commercial RO membrane surfaces. RESULTS The properties of PEI‐modified membranes were analyzed, such as surface charge, morphology and hydrophilicity. The results showed that zeta potential at pH 7 increased from −22.89 mV to 20.19 mV, which indicated that surface charge altered from negative to positive. Meanwhile, hydrophilicity of membranes was improved since the contact angle decreased from 65° to 36°. The decontamination factor (DF) of cesium(I) increased from 11.69 to 114.23 and the DF of cobalt(II) increased from 28.62 to 3306.88. CONCLUSION The laboratory‐scale experiments with cross‐flow demonstrated the effective rejection of nuclides without obvious membrane flux loss of PEI‐modified membranes. In addition, PEI‐modified membranes offered a stable nuclides removal under high‐level background boron and various pH conditions, which demonstrated a possible application in boron‐containing LRW treatment. © 2019 Society of Chemical Industry