A comprehensive study of recent advances, challenges and factors of nanofiltration membrane in various industrial applications
Zubaida Rukhsana Usha, Cui Liu, Shudong Zhang, Zhenyang Wang
Abstract
Nanofiltration (NF) membrane was first introduced in the late 1980s, which shows the membrane properties between ultrafiltration and reverse osmosis . Impressively, the NF membrane represents significant unique properties such as enhanced selectivity toward divalent/polyvalent ions while enabling permeability of monovalent ions and small molecules <100 Da. These properties play an increasingly large role in a variety of applications, such as waste water treatment (desalination, water softening, and fluoride removal), pharmaceutical and biotechnology uses, food and non-aqueous applications, and others. Beyond all of its unique properties, NF has to negotiate a few limitations such as temperature stability, flux/rejection trade-offs, and membrane fouling . Hence, adjusting surface chemistries and morphologies through several modification processes enables NF membranes to be tuned for a certain application to achieve optimal performances. The physical/chemical interaction occurring at the surface or interface in the NF surface modification process has been proven to effectively regulate and improve crucial parameters of the NF membrane. Herein, this review will be conducted as an in-depth study of the recent advances and achievements of NF membranes. Meanwhile, several typical surface modification processes have all been utilized to produce better NF membrane properties. Finally, further prospects for various NF applications with significant challenges are highlighted in detail.