Ultrafiltration is a membrane separation process (as well as fractionation and concentration) of substances, carried out by filtering a liquid under pressure through a semi-permeable membrane. The pore size of the ultrafiltration membrane varies from 0.01-0.1 µm. The main materials for the manufacture of ultrafiltration membranes are polymers and ceramics.

When water is treated on ultrafiltration membranes, colloidal particles, microorganisms (bacteria and viruses), large organic macromolecules that determine the color of water (humic and fulvic acids) are extracted from it.

Ultrafiltration technology has received the widest application for preliminary preparation of source water for reverse osmosis plants.

To filter water using ultrafiltration technology, the dead-end filtration mode with regeneration of the filtrate by reverse flow is most often used. In this case, the membrane works for some time in a dead-end mode, and then the direction of solution movement is reversed. The contaminants retained by the membrane are partially or completely removed from its surface, and the filtration cycle is repeated. In the event that impurities are not completely removed during backwashing of the filtrate, chemically enhanced backwashing is periodically used, in which reagents are dosed into the wash water stream.

To ensure the stable operation of the ultrafiltration water installation in Ukraine, in such large cities as Kyiv, Dnipro, Zaporozhye, Kharkov, Lvov, Odessa and other cities to prevent failure of the membrane ultrafiltration modules, the installations must be equipped with the following minimum required units:

– a pre-filter (most often, a self-cleaning mesh filter);

– coagulant dosing station (not always used);

– block of ultrafiltration modules;

– filtrate storage capacity;

– backwash pumping station;

– reagent dosing stations for chemically enhanced backwashing;

– piping and artamura;

– control cabinet, instrumentation.

Advantages of ultrafiltration technology:

– low power consumption;

– low water consumption for own needs;

– compactness;

– removal of viruses and bacteria;

– wide possibilities of process automation and integration into existing systems.

Disadvantages of Ultrafiltration Technology

– high cost of membrane modules;

– the operation process is possible only in automatic mode.