ultrafiltration

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ultrafiltration

chemistry

Also known as: UF

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July 23, 2026

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Ultrafiltration is a type of membrane filtration that uses a semipermeable membrane to separate molecules. It is driven by a pressure difference, which accelerates the diffusion of smaller molecules through the membrane while retaining larger ones. This process is distinct from osmosis, where only the solvent moves across a membrane.12

Ultrafiltration is used in various applications, including concentrating impurities, recovering solvents, and purifying water. A related technique, electro-ultrafiltration, utilizes electroosmosis to achieve ultrafiltration. This method is a barrier separation technique, relying on the properties of the membrane to achieve its separation goals.13

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dialysis
…this process is prevented by ultrafiltration, by which some of the water, along with some dissolved materials, is forced through the membrane by maintaining the blood at a higher pressure than the solution.
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…this process is prevented by ultrafiltration, by which some of the water, along with some dissolved materials, is forced through the membrane by maintaining the blood at a higher pressure than the solution.
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cheese making
Inoculation and curdling
…in a process known as ultrafiltration. The milk is then inoculated with fermenting microorganisms and rennet, which promote curdling.
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…in a process known as ultrafiltration. The milk is then inoculated with fermenting microorganisms and rennet, which promote curdling.
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separation and purification
Barrier separations
In ultrafiltration, this diffusion through the membrane is accelerated by means of a pressure difference. In electrodialysis, an electrical field accelerates the migration.
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In ultrafiltration, this diffusion through the membrane is accelerated by means of a pressure difference. In electrodialysis, an electrical field accelerates the migration.
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human cardiovascular system
The capillaries
…membranes by a process called ultrafiltration. Only 1/1,000th of the surface area of capillaries is represented by these pores. Other substances, such as cholesterol, are transported by specific receptors in the endothelium.
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…membranes by a process called ultrafiltration. Only 1/1,000th of the surface area of capillaries is represented by these pores. Other substances, such as cholesterol, are transported by specific receptors in the endothelium.
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renal system
Formation and composition of urine
A large volume of ultrafiltrate (i.e., a liquid from which the blood cells and the blood proteins have been filtered out) is produced by the glomerulus into the capsule. As this liquid traverses the proximal convoluted tubule, most of its water and salts are reabsorbed, some of the solutes…
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A large volume of ultrafiltrate (i.e., a liquid from which the blood cells and the blood proteins have been filtered out) is produced by the glomerulus into the capsule. As this liquid traverses the proximal convoluted tubule, most of its water and salts are reabsorbed, some of the solutes…
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water supply system
Membrane filtration
…filtration systems include microfiltration (MF), ultrafiltration (UF), and reverse osmosis (RO); they differ basically in the pressures used and pore sizes of the membranes. RO systems operate at relatively high pressures and can be used to remove dissolved inorganic compounds from water. (RO is also used for desalination, described below.)…
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…filtration systems include microfiltration (MF), ultrafiltration (UF), and reverse osmosis (RO); they differ basically in the pressures used and pore sizes of the membranes. RO systems operate at relatively high pressures and can be used to remove dissolved inorganic compounds from water. (RO is also used for desalination, described below.)…
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