As we all know, reverse osmosis membrane technology is a very widely used technology in water treatment. The specific mechanism is to increase the pressure exceeding the osmotic pressure of the aqueous solution on the concentrated solution side to drive the reverse moisture. Today, I will introduce the reverse osmosis membrane technology in the membrella ro membrane.
Because under reverse osmosis conditions, the water on the side of the concentrated solution will flow into the diluted solution according to the semi-permeable membrane, and the concentration of most substances (solubility solid) cannot pass through the membrella ro membrane and be cut off. Therefore, the concentrated solution is further concentrated.
In practical applications, since the reverse osmosis element membrane and the pulse damper themselves have frictional resistance to the fluidity of water, the pressure used to complete the reverse osmosis process on the reverse osmosis membrane is much higher than the osmotic pressure of the aqueous solution.
The osmotic pressure of brackish water at a concentration of 1500ppmt is about 15psi, but its actual operating pressure is likely to be 150~300psi; while the osmotic pressure of seawater at a concentration of 35000ppmtds is about 350psi, and the actual operating pressure is likely to be 800 psi ~1200psi. It is not difficult to see that a large part of the driving pressure of the reverse osmosis membrane system is used to resist the frictional resistance of the reverse osmosis element membrane and the pulse damper itself to water; especially for low-salinity water resources, this situation will become more and more more pronounced. Therefore, for water treatment equipment, it is very important to choose suitable membrane elements.
Although the use of reverse osmosis membrane technology has been very perfect at this stage, there is no unified conclusion on the principle of reverse osmosis in the industry. Many models have been used to describe the entire reverse osmosis process, and they have different complexity depending on different assumptions.