The working principle and application of RO membrane

2021-11-29

In previous presentation, we mentioned that Ro membrane is made of a kind of high molecular nano-level chemical synthesis material. The pore size of this aromatic polyamide is only ranging from 0.001 to 0.0001 micron.

The size of most bacteria is between 0.5 and 5 micron, and size of viruses is between 0.01 and 0.1 micron, which indicate bacteria and viruses cannot pass through polyamide pores that are much smaller than their own sizes. So, after filtering through the RO membrane, the water is bacteria and viruses free. This ensures the safety of drinking water.

The obvious advantage of RO membrane is to reduce the hardness of water. It can remove up to 99% of contaminants from the pre-filtered water, such as calcium, magnesium, sodium, and iron. Because of the small pore size, a reverse osmosis membrane allows the passage of water molecules but not the majority of dissolved salts, organics, bacteria and pyrogens.

Therefore, the water filtered by RO membrane, no matter how it is boiled or how long the kettle is used, there is no scale.

The current ro element is spiral-wound reverse osmosis membrane. The direction of water flow is parallel to the surface of ro membrane, which has much better performance than the plate membrane. Its direction of water flow is vertical to the filter diaphragm, so the plate membrane is easier to be blocked by the particles in raw water, and also results in short service life.

The spiral-wound process technology can solve this problem well. Due to the parallel water flow direction, the surface of membrane is rinsed cleanly and the life of the membrane is very good. Some industrial membranes can even be used for 8 years, which is extremely rare in the field of filter element.

 

What is the application of ro membrane?

For the public, the most frequently application is the filter element in water purifier. But RO membranes have been widely used in the field of water treatment, such as seawater desalination projects, industrial water treatment, tap water plants, filling water plants, food and beverage plants, boiler water plants, power plants, etc.

There is no doubt that without RO membrane, there will be no water treatment industry. RO membrane is the chip of water treatment industry, especially in the field of water purification.