Membrane Technologies

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The principle of the separation process based on membrane technologies is mechanical filtration of the liquid medium (marine, brackish water, drinking water, waste water, process water, etc.) through a membrane module. The essence of this technology is a semipermeable membrane which allows the molecules of water and depending on the type of membrane, also the other selected particles up to certain size to pass through the membrane.

Semi-permeable membranes are characterized mainly by the pore size, which determines the size of the particles which are allowed to pass through the module. Since the filtration through the membrane ensures to separate any solid particles, thus filtered raw water is hygienically secure.

Membrane technology is used in the petrochemical industry (wastewater disposal, re-use of process water), pharmaceutical industry (infusion solutions, drugs production), food industry (water for beverage production and processing of fruit and vegetable juices, milk processing) as well as in water treatment in waterworks, power plants and heating plants (demineralised cooling water, auxiliary boiler feed water).

Process	Pore size	Separation
Reverse osmosis	0.001 - 0.0001 µm	monovalent ions, all soluble compounds
Nanofiltration	0.01 - 0.001 µm	polyvalent ions, dissolved organic compounds (pesticides, disinfection by-products)
Ultrafiltration	0.1 - 0.01 µm	macromolecules, organic substances (viruses, bacteria), colloidal substances

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