 The application of membrane technology in water and wastewater treatment is increasing due to stringent water quality standards. Nanofiltration, NF, is one of the widely used membrane processes for water and wastewater treatment in addition to other applications such as desalination. NF has replaced reverse osmosis, RO, membranes in many applications due to lower energy consumption and higher flux rates. This paper briefly reviews the application of NF for water and wastewater treatment including fundamentals, mechanisms, fouling challenges and their controls. This article was authored by H. K. Sean, S. Funcho, D. S. Chaudhary and others.