Recent development in nanofiltration process applications

In the past few decades, membrane filtration has emerged as one of the most versatile separation technologies that have found widespread applications in various sectors. Among the membrane processes currently present in the market, nanofiltration (NF) membranes are expected to observe increasing interest due to their unique properties and versatility as a separation process. NF membranes typically possess a membrane pore size of 0.5–2.0 nm (corresponding to a molecular weight cutoff of 100–5000 Da), which is in between the range of ultrafiltration (UF) and reverse osmosis (RO). NF membranes also exhibit a certain level of surface charge due to the presence of a few particular functional groups on the membrane surface. These characteristics grant the NF membranes the ability to reject impurities based on two main mechanisms: electrostatic repulsion and steric hindrance. Consequently, NF membranes have found niche applications where not only it can remove the impurities that UF membranes fail to but also enjoy the benefits of having higher water flux (lower energy consumption and cost) compared to RO. Thus NF has found wide applications across different industrial sectors such as used for water and wastewater treatment, desalination, food industry, biorefinery applications, and organic solvent separation to name a few.