A filtration process that uses membranes to preferentially separate different fluids or ions. Although nanofiltration is not as fine a filtration process as reverse osmosis, it requires the same energy to perform the separation.
A lower pressure membrane treatment technology sometimes used for pretreating reverse osmosis feedwater.
Crossflow membrane separation process for removing particles in the 250 to 1000 molecular weight range, selected salts and most organics. Nanofiltration is often used for water softening and require lower driving pressure than RO.
A form of filtration that uses a membrane to separate different fluids or ions.
Filtration of minute particles from water using a filter with extremely small pores (10-3 microns in diameter).
A membrane treatment process which falls between reverse osmosis and ultrafiltration on the filtration/separation spectrum.
Nanofiltration is a relatively recent membrane process used most often with low TDS waters such as surface water and fresh groundwater, with the purpose of softening (polyvalent cation removal) and removal of disinfection by-product precursors such as natural organic matter and synthetic organic matter Water Quality & Treatment, 5th Ed. American Water Works Association, 1999. http://www.dow.com/liquidseps/prod/app_nano.htm Nanofiltration Membranes and Applications.