MF, UF, NF or RO: which membrane for which job?

Microfiltration has pores of roughly 0.1 to 10 micrometres and removes suspended solids and most bacteria. It is often used for clarification and as pre-treatment.

Ultrafiltration pores are about 0.01 to 0.1 micrometres. UF removes colloids, bacteria and most viruses while letting dissolved salts pass. It is the standard pre-treatment for reverse osmosis and the heart of membrane bioreactors.

Nanofiltration removes hardness, colour and many organic molecules, and passes part of the monovalent salts. Reverse osmosis uses a dense membrane that rejects almost all dissolved salts, which is why it is used for desalination, boiler feed and high-purity water.

The higher the rejection, the higher the operating pressure and energy use, so the right choice is the loosest membrane that meets the target. Theway Membranes, India's first commercial manufacturer of hollow-fibre UF membranes, supplies UF and MBR modules and RO and NF elements, including direct retrofits for other brands.

Supplied in Europe

In the European Union, Davey Group equipment is supplied, contracted and supported by VDT Europa OÜ in Tallinn, Estonia. Contact contact@vdteuropa.com.