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.
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 for blood treatment, wastewater treatment and ultra-pure water preparation of the terminal treatment device. In our country has been successfully used in 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 polymers, and the like.
The ultrafiltration membrane was used to filter the ultrafiltration membrane with the pressure difference as the driving force. The ultrafiltration membrane is mostly made from cellulose acetate or a polymer material similar to its properties. It is most suitable for the separation and enrichment of solute in solution, and it is also used in the separation of colloidal suspensions which are difficult to complete with other separation technologies, and its application field is expanding.
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 membrane, through a simple backwash difficult to clean, non-hydrophilic film operating pressure High and high frequency of chemical cleaning;
The hydrophobic ultrafiltration membrane in the filtration of the mass transfer process, colloid, oil, protein and other pollutants in the membrane surface agglomerate into a spherical shape, this spherical aggregates, it is easy to detach from the membrane surface, through a simple anti Wash can be cleaned, hydrophilic ultrafiltration membrane operating pressure is low and chemical cleaning frequency is low.