Ultrafiltration is a membrane filtration process where liquids are pushed with hydrostatic pressure through a semipermeable membrane. Fundamentally UF is a pressure driven separation process dependent on particle size. On lower pressures particles categorized by size are separated.

Macromolecular separation occurs on particles sized between 10-1000A^o1. Total Dissolved Solids and smaller molecules pass through the membrane. Some of the removed materials are; colloids, proteins, microbiological contaminants and large organic molecules.

Aside from water and wastewater treatments UF membranes are used in pharmaceutical, automotive, chemical, food and drink industries. Also, UF is used in vaccines, fermentation products, enzymes and separation of proteins.