Physical Chemistry. a filter for purifying sols, having a membrane with pores sufficiently small to prevent the passage of the suspended particles.
Mathematics. a filter in a topological space, having the property that no other filter exists in the space having among its subsets all the subsets in the given filter.

verb (used with object)

Physical Chemistry. to purify by means of an ultrafilter.

Origin of ultrafilter

Related formsul·tra·fil·tra·tion [uhl-truh-fil-trey-shuh n] /ˌʌl trə fɪlˈtreɪ ʃən/, noun
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Examples from the Web for ultrafiltration

Contemporary Examples of ultrafiltration

  • Ultrafiltration membranes remove more than 99 percent of bacteria, molds, and spores from drinking water, and can be used at home.

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    Technologies That Empower Women

    Tom Watson

    March 7, 2010

British Dictionary definitions for ultrafiltration



a filter with small pores used to separate very small particles from a suspension or colloidal solution
Derived Formsultrafiltration (ˌʌltrəfɪlˈtreɪʃən), noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

ultrafiltration in Medicine




The filtration of a colloidal substance through a semipermeable medium that allows only small molecules through.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.