421605 Novel Nanofiltration Membrane with a Sulfonated Copolymer Selective Layer for the Removal of Heavy Metals

Thursday, November 12, 2015: 8:55 AM
155F (Salt Palace Convention Center)
Zhiwei Thong1, Gang Han1, Yue Cui2, Jie Gao1, Tai-Shung Chung2, Sui Yung Chan3 and Shawn Wei4, (1)Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore, (2)Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore, (3)Pharmacy, National University of Singapore, (4)Kraton Performance Polymers, Houston, TX

Facing increasing stringent regulations on wastewater discharge containing heavy metal ions, various industries are demanding more efficient and effective treatment methods. Among the various methods available, nanofiltration (NF) has been proven to be a feasible and promising option. However, it should be noted that the development of new membrane materials is constantly required for the advancement of this technology. To this aim, this study reports the first attempt to develop a composite NF membrane comprising of a molecularly designed pentablock copolymer selective layer for the removal of heavy metal ions. The resultant NF membrane has a reasonably high pure water permeability (A) of 2.4 LMH/bar with a mean effective pore diameter of 0.50 nm and molecular weight cut-off of 255 Da. In addition, the newly developed NF membrane can effectively remove heavy metal cations such as Pb2+, Cd2+, Zn2+ and Ni2+ with a rejection greater than 98.0%. Furthermore, the membrane also shows reasonably high rejections towards anions such as HAsO42- (99.9%) and HCrO4- (92.3%). This observed performance can be attributed to (1) the incorporation of polyethyleneimine (PEI) as a gutter layer between the selective layer and the substrate and (2) the pentablock copolymer’s unique ability to form a continuous water transport passageway with a defined pore size. The promising preliminary results achieved in the current study provide a useful platform for the development of new NF membranes for the removal of heavy metals.

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See more of this Session: Membranes for Water Treatment Applications IV
See more of this Group/Topical: Separations Division