Reverse osmosis technology is the most advanced and most energy-saving and effective membrane separation technology today. The principle is that under the action of higher than the osmotic pressure of the solution, other substances cannot pass through the semi-permeable membrane and these substances and moisture are removed. Because the pore size of the reverse osmosis membrane is very small (only about 10A), it can effectively remove dissolved salts, colloids, microorganisms, and organic matter in the water (removal rate as high as 97-98%). The system has the advantages of good water quality, low energy consumption, no pollution, simple process and easy operation.
Reverse osmosis technology is usually used in sea water, brackish fresh water; water softening treatment; wastewater treatment and purification, concentration, separation and other aspects of food, pharmaceutical industry, and chemical industry. In addition, the application of reverse osmosis technology to pre-demineralization treatment has also achieved good results, which can reduce the load of ion exchange resin by more than 90%, and the amount of resin regeneration agent can also be reduced by 90%. Therefore, it not only saves costs, but also contributes to environmental protection. Reverse osmosis technology can also be used to remove particles, organic substances, and colloids in the water, and has a good effect on reducing the pollution of ion exchange resins and extending the service life.
Reverse osmosis is currently the most widely used desalination technology in the preparation of high-purity water. Its separation object is organic matter with a range of ions and a molecular weight of several hundred in the solution. Reverse osmosis (RO), ultrafiltration (UF), microporous membrane filtration ( MF) and electrodialysis (ED) technologies are both membrane separation technologies.
In the past 30 years, reverse osmosis, electrodialysis, ultrafiltration and membrane filtration have entered industrial applications and have developed rapidly. In the semiconductor, integrated circuit manufacturing process, food, and pharmaceutical industries, reverse osmosis is usually used as desalination in the preparation of high-purity water. Ultrafiltration is mostly used as the post-treatment of the water system, while membrane filtration is used for the pre-treatment and post-treatment of water treatment to filter particles and bacteria.