Compared with GE reverse osmosis membrane, the desalination rate of Dow reverse osmosis membrane is 0.2 points higher, the pressure is 50PSI lower and the price is high 10%.
Generally speaking, reverse osmosis membrane will be much better. Ultrafiltration membrane, nanofiltration membrane and reverse osmosis membrane are introduced below.
Ultrafiltration: The filter membrane with the pore size of 0.0 1 micron to 0. 1 micron is used as the medium for filtering water, which can not only intercept colloid, rust, suspended matter, sediment, macromolecular organic matter and other pollutants, but also remove some large-diameter bacteria and viruses. However, for harmful substances such as microorganisms and heavy metal ions whose diameter is less than 10nm, ultrafiltration membrane can do nothing.
Nanofiltration: the pore size of nanofiltration membrane is about 1nm, which is between ultrafiltration membrane and reverse osmosis membrane and closer to reverse osmosis membrane. The desalination rate of nanofiltration is above 90% (the desalination rate of reverse osmosis is above 99%), which is essentially low-pressure reverse osmosis. It is used to treat occasions where the purity of produced water is not particularly strict, and now it is mainly used for seawater desalination in water plants or industries.
Reverse osmosis: The pore size of reverse osmosis membrane is about 0. 1nm, and the filtration accuracy is the highest among the four kinds of filtration membranes. Its filtering aperture is one millionth of that of hair and one fifth of that of bacteria and viruses, which can effectively intercept various harmful substances in water. The water purified by reverse osmosis water purifier is pure water and can be directly drunk.