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Reverse Osmosis


A Reverse Osmosis System, RO-System or just RO, is a machine to purify liquids, mainly water. This water holds normally too many inpurities to be used direct, such as bore well water or very typical seawater, which is desalinated. The heart of a RO is the membrane with very thin holes. clean waterThese holes are so small, that only water molecules can pass these holes, but all the impurities organic and an-organic are not able to pass. The principal of such a membrane is based on the natural osmosis effect. By having high pressure on one side of the membrane the natural osmosis effect is reversed. Only the small enough particles are pressed through the membrane, and the thicker parts are kept outside the membrane, and will be drained as the so called brine.
As feed water very often seawater or bore well water with high concentration of solids is used, both water which can hardly be used as drinking water or water for high demanding technical purposes without being treated or purified.
Technically this process causes a row of problems. As from the feed water, the pure water is pressed through the membrane, what is left, the so called brine, very often has very high concentrations of TDS.
 
This water then causes problems of scaling and fouling, both in the membrane itself, but also at the inlet to the membrane. If not treated well, such a RO-membrane can be blocked after a short time and has to be replaced. If brackish water is used, which happens often near the sea, where in shallow waters grow a lot of algae, there is as well a risk of biological contamination of the membrane, which lead in the end to the need of replacing the membrane.
Pursanova DiskTM are used in front of RO Systems and normally installed ahead of the pre filter in the feed line. It could be found big improvements starting in the pre filter, but especially at the membrane itself. In the pre filter less scaling happens so the lifetime of the pre filter can be 5 to 10 times longer. There is no or far less scaling happening inside the RO itself, hence the pressure and the production stay stable over far longer time, the need of replacing the membrane is lesser then before. See as well a case study from Saudi Arabia.