Reverse osmosis method can remove more than 90 % of soluble salts and 99 % of colloidal microorganisms and organic matter from water. Especially the brackish water purification plant by reverse osmosis powered by wind and solar energy is an economical and reliable way to solve the water problem of people in areas without electricity and short of conventional energy. Reverse osmosis desalination is not only suitable for seawater desalination, but also for brackish water desalination. Of the existing desalination methods, reverse osmosis desalination is the most economical, it has even exceeded the electrodialysis desalination. As the driving force of reverse osmosis process is pressure, there is no phase change in the process, and the membrane only plays the role of "screening", so the energy consumption of reverse osmosis separation process is low. In existing seawater and brackish water desalination, reverse osmosis is the most energy saving. Reverse osmosis membrane separation is characterized by its "broad spectrum" separation, that is, it can not only remove all kinds of ions in the water, but also can remove particles larger than the ions, such as most of the organic matter, colloid, virus, bacteria, suspended matter, so reverse osmosis separation method is also known as broad spectrum separation.
The pretreatment of reverse osmosis water treatment system can ensure the stable operation and service life of reverse osmosis device, and has the following functions:
(1) To prevent scaling on the film surface (including CaCo3, CaSO4, SrSO4, CaF2, SiO2, iron and aluminum oxide, etc.);
(2) to prevent colloidal substances and suspended solid particles fouling;
(3) to prevent pollution and blockage of organic matter;
(4) to prevent microbial fouling;
(5) to prevent oxidative damage to the film by oxidizing substances;
(6) Keep the water yield of reverse osmosis device stable.
Reverse osmosis water treatment pretreatment system: iron and manganese filter, multi-media filter, activated carbon filter, sodium ion exchanger, precision filter, ultrafiltration.