Ultrafiltration (industrial)

Ultrafiltration is a type of crossflow filtration. Industries such as chemical and pharmaceutical processing, food and beverage processing, and waste water treatment, employ ultrafiltration in order to recycle flow or add value to later products. UF's main attraction is its ability to purify, separate, and concentrate target macromolecules in continuous systems. UF does this by pressurizing the solution flow, which is tangential to the surface of the supported membrane (cross-flow filtration). The solvent and other dissolved components that pass through the membrane are known as permeate. The components that do not pass through are known as retentate. Depending on the Molecular Weight Cut Off (MWCO) of the membrane used, macromolecules may be purified, separated, or concentrated in either fraction. Currently, the study of UF processing occurs mainly in laboratory setups because it is very prone to membrane fouling caused by increased solute concentration at the membrane surface (either by macromolecular adsorption to internal pore structure of membrane, or aggregation of protein deposit on surface of membrane), which leads to concentration polarization (CP). CP is the major culprit in decreasing permeate flux. Ultrafiltration is used in reverse osmosis processes in many Middle Eastern countries to produce fresh water as there is little fresh water available in those areas.