What does ultrafiltration mean?
Ultrafiltration is a technical membrane-separation method used to concentrate, fractionate, or purify liquid samples. Pressure forces a solution through a semipermeable membrane whose pores allow water and smaller dissolved substances to pass while retaining macromolecules such as proteins, polysaccharides, and some microorganisms. The process can operate in dead-end or tangential-flow arrangements and may be repeated to achieve greater concentration or purification. Ultrafiltration is especially important in biotechnology, pharmaceutical production, laboratory research, food processing, and wastewater treatment. Unlike ordinary coarse filtration, it separates on the scale of individual macromolecules; unlike nanofiltration, it generally concentrates or removes larger biological molecules rather than targeting small dissolved ions and organic compounds. The word is correspondingly technical and process-oriented, with no strong regional or emotional connotations.
nounUltrafiltration is a membrane-separation process in which pressure forces a solution through a semipermeable membrane that retains macromolecules such as proteins while allowing the solvent and smaller solutes to pass. It is used to concentrate, fractionate, or purify substances.
- A membrane-separation process that concentrates or purifies a solution by retaining macromolecules while allowing the solvent and smaller solutes to pass through a semipermeable membrane.
"Each round of ultrafiltration concentrated the purified protein before it was collected."
"The technician monitored the ultrafiltration process as pressure increased across the membrane."
"Wastewater underwent ultrafiltration before the recovered concentrate was analyzed for pollutants."
The plural is grammatically regular but uncommon; writers often use the singular when referring to the general technique.
"The researchers repeated the ultrafiltrations under identical pressure and temperature conditions."
Ultrafiltration acts like a molecular sieve: proteins stay behind while water and smaller dissolved substances pass through.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does ultrafiltration come from?
The word combines the Latin-derived prefix ultra-, meaning “beyond,” with filtration, denoting the separation of material from a fluid by a filtering medium. Filtration comes through French from Latin filtrare, a verb based on filum, meaning “thread.” The compound developed as a name for the fine membrane separation used in modern laboratory and industrial processes; related English words include filter, filtrate, and filtration.
How ultrafiltration is actually used
This is primarily a formal scientific and industrial term used in chemistry, biochemistry, biotechnology, pharmaceuticals, and water treatment. It names a filtration process, not the material retained or the resulting filtrate.
Easily confused with ultrafiltration
Microfiltration generally removes suspended particles, cells, and microorganisms, whereas ultrafiltration is designed to retain dissolved macromolecules such as proteins.
Ultrafiltration separates primarily by the size of retained macromolecules, while nanofiltration uses tighter membranes and can also separate many small solutes and multivalent ions.