In-situ interfacial polymerization of zwitterionic nanofiltration membranes with anti-scaling performance
Yue Shen, Gilles Van Eygen, Bin Wu, Chao Wu, Ming‐Jie Yin, Yan Zhao, Bart Van der Bruggen, Quan‐Fu An
Abstract
Mineral scaling caused by multivalent metal ions can significantly hinder the long-term operation of nanofiltration membranes. In this study, in-situ interfacial polymerization including a posttreatment by using a citric acid solution was employed in order to mitigate scaling on the membrane surface. Under the optimal conditions (15 min of posttreatment with a 2 M citric acid solution), the membrane water permeance increased from 5.76 ± 0.23 to 15.1 ± 1.8 L m−2 h−1·bar−1 for the pristine and the optimal membrane, respectively. The molecular weight cut-off of the optimal membrane was 399 Da, which allows for the removal of organic micropollutants in groundwater. Furthermore, the resulting membrane showed a Na2SO4 and CaCl2 rejection of 92.5 ± 1.9 and 11.4 ± 1.3%, respectively. During the anti-scaling tests, the membranes fabricated with this strategy exhibited a minor decline of the water permeance of 33.5% when subjected to the same water recovery process, opposed to 65.8% for the pristine membrane. This proposed fabricating procedure thus provides an effective strategy for retarding membrane scaling in desalination applications.