Microfiltration
Microfiltration (MF) has significant applications in simple dead-end filtration for water, sterile fruit juices and wine, and aseptic pharmaceuticals. However, not all applications that benefit from MF operate successfully in the dead-end mode, and a large portion of the MF market has been captured by crossflow.
Nanofiltration is a relatively recent membrane filtration process used most often with low total dissolved solids water 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.
The most common of these is the clarification of whole cell broths and purification processes in which macromolecules must be separated from other large molecules, proteins, or cell debris. Clarification of dextrose and highly-colored fruit juices employ MF extremely well. There are also large markets for MF crossflow filtration in wine production, milk and whey de-fatting, and brewing. As with ultrafiltration, MF systems operate at relatively low pressures and come in a variety of configurations.