A UF membrane is a fine filter that can reduce particles that are 5,000 times smaller than a human hair. It works by forcing liquid against the membrane, which retains suspended solids and high molecular weight solutes, while allowing water and low molecular weight solutes to pass through. Key FeatureUF membrane with pore sizes in the range of 0.1 to 0.001 micron typically remove high molecular-weight substances, colloidal materials, and organic and inorganicpolymeric molecules, bacteria except minerals. Low applied pressures are sufficient to achieve high flux rates from an ultra filtration membrane.