What Is Ultrafiltration?

Ultrafiltration (UF) is a pressure-driven purification process that separates particulate matter from soluble components. Membranes reject particulates that are 0.01 microns and larger thus producing high quality water.

The Process

UF is a pressure driven purification process. Feed solution is pumped at low pressures across the surface of a thin, polymeric semi-permeable membrane. Solutes whose sizes are greater than the pore size of the membrane and all suspended solids are retained and concentrated. Water, salts and smaller molecular weight constituents pass through, or permeate, the membrane. The pore structure of the membrane acts as a molecular filter that does not become plugged because the retained components of the feed are rejected at the surface and do not permeate the membrane. The membrane barrier will remove particles as small as 0.01 mirons including bacteria, viruses and colloids. UF is often used as a pre-treatment for RO to reduce the fouling of expensive RO membranes.

Benefits of UF

  • Enable manufacturers to meet stringent water standards
  • Stable reliable and consistent water quality
  • No chemicals required (aside from cleaning) and so no associated costs for sludge disposal.
  • Compact plant size, small footprint and less weight

Ultrafiltration, (UF) is typically used to remove colour, odor and some colloidal natural organic matter and is often used as a pre treatment to RO, nanofiltration and electrodialysis.


Envirogen Water Technologies