Hydrophilic membrane is a kind of ultrafiltration membrane, you can filter some of the harmful substances in the water, this membrane can be filtered under a small pressure of water. Ultrafiltration membrane principle: ultrafiltration is a membrane pore size associated with the screening process , The pressure difference on both sides of the membrane as the driving force to the ultrafiltration membrane as the filter medium, under a certain pressure, when the original liquid flows through the surface, the ultrafiltration membrane surface of many small pores only allow water and water molecules The material through the liquid into the liquid, and the liquid in the liquid on the membrane surface microporous material is trapped in the membrane on the liquid side, as the concentrate, so the realization of the liquid purification, separation and enrichment purposes.
Ultrafiltration membrane is widely used in industrial applications, has become one of the new chemical unit operation. For the separation, concentration, purification of biological products, pharmaceutical products and food industry; also used in blood treatment, wastewater treatment and ultra-pure water preparation of the terminal treatment device. In our country has successfully used the ultrafiltration membrane of Chinese herbal medicine concentrated purification. Ultrafiltration membrane with the progress of technology, its screening function will be improved and strengthened, the contribution of human society will be more and more.
The structure of the ultrafiltration membrane is symmetrical and asymmetric. The former is isotropic, no cortex, all directions of the pores are the same, belonging to the deep filter; the latter has a more dense surface and finger-based structure of the bottom, the surface thickness of 0.01 microns or less, And has a row of ordered micropores, the bottom thickness of 200 to 250 microns, belonging to the surface filtration. Industrial use of ultrafiltration membrane is generally asymmetric membrane. The membrane material of the ultrafiltration membrane is mainly cellulose and its derivatives, polycarbonate, polyvinyl chloride, polyvinylidene fluoride, polysulfone, polyacrylonitrile, polyamide, polysulfone amide, sulfonated polysulfone, Polyvinyl alcohol, modified acrylic polymer, and the like.
Non-hydrophilic ultrafiltration membrane, in the filtration of the mass transfer process, colloid, oil, protein and other pollutants into a cake-like surface attached to the film, through a simple backwash difficult to clean, non-hydrophilic film operating pressure High and chemical cleaning frequency is high; and hydrophilic ultrafiltration membrane in the filtration of the mass transfer process, colloid, oil, protein and other pollutants in the membrane surface agglomeration into a spherical, this spherical aggregates, it is easy from the membrane Surface detachment, through a simple backwash can be cleaned, hydrophilic ultrafiltration membrane operating pressure is low and chemical cleaning frequency is low.
Hydrophilic ultrafiltration membrane chemical cleaning cycle is relatively long, chemical cleaning recovery is better, in each chemical cleaning cycle, backwash after the flux recovery close to 100%; non-hydrophilic ultrafiltration membrane chemical cleaning cycle is short, The flow rate of backwash after each chemical wash cycle is only 80-90%; therefore, in the water treatment project, the hydrophilic ultrafiltration membrane than the non-hydrophilic ultrafiltration membrane has obvious advantages, Life, well maintained in a stable flow - design flow.