The application of membrane separation technology in wastewater treatment
water resource is the indispensable natural resources, human and biological survival environment and resources. To deal with industrial or domestic wastewater and converted into can drink the water or can once again use has become an important way to solve the crisis of water resources. To the problem of sewage treatment is currently using more biochemical treatment. But this method needs a lot of space, for building a conservation-minded society, save a space for the water treatment technology is of great importance. Membrane separation technology is to use a special choice performance of film, under the driving force of mixture separation, purification, concentration of a kind of new method for separation. The film must be able to make some material through, some characteristics of the material cannot pass. This film can be a solid, liquid or gas phase, but the use of the vast majority are solid phase membrane.
1。 Using the principle of physical properties
the membrane separation technology can use a mixture of different physical properties, such as quality, size, or the geometry of the difference, membrane used as sieve, its separation.
2。 By using the principle of chemical properties
mixture separation membrane speed may be regarded as the speed of the two steps. A speed from the speed of film surface contact mixture into the film inside, the dissolution rate. Dissolution rate depending on the mixture and chemical properties of materials used in separation membrane. After the second speed is into the membrane from the membrane surface speed of spread to the other side of the membrane, the diffusion speed. Diffusion velocity in addition to the associated with the chemical properties of the mixture and membrane, also associated with the relative molecular mass of material. See http:// for specific more related technical documents.
3。 The types of membrane separation technology
microfiltration separation technology ( MF)
microfiltration separation technology is based on the principle of the sieve with pressure difference as driving force of membrane separation process. Under the given pressure ( 50 ~ 100 kpa) , solvents, salts and macromolecular substances can through the aperture is 0. 1 ~ 20. 0 microns microfiltration membrane, only fine particles larger than 50 nm in diameter and large molecules trapped filtering, so as to make the solution or purified water. It is a kind of precision filtration technology, its principle is similar to ordinary filter, filter particles than ordinary small but many, is the latest development of filtering technology.