Membrane separation in the early 20th century, after the rapid rise in the 1960s of a new separation technologies. Membrane separation technology because both the separation, concentration, purification and refining capabilities, but also efficient, energy saving, environmental protection, molecular stage filtration and filtration process is simple, easy to control, and other characteristics, therefore, has been widely used in food, medicine, biology, environmental, chemical, metallurgy, energy, petroleum, water treatment, electronics, bionics and other areas, resulting in huge economic and social benefits, has become one of the most important means of science in today's separation.
The membrane may be solid, liquid, or even a gas phase. Produced by a variety of natural or artificial material film variety, on the physical, chemical and biological properties exhibit a variety of characteristics. All along, the concept of the film are not clearly defined, experts in different areas of research are not the same understanding of the definition of the film, but the basic meaning of the expression is the same. 1984, Lakshminarayanaiah broadly defined the film as "play the role of the fence, to prevent mass movements and allow one or several species ordered by a phase." Film broadly be defined as a discrete interval between the two phases. And the rest was much smaller compared to twice the range of the three-dimensional measurement.
Most people would think that the film is very distant from our lives. In fact, membrane separation technology is very close to our daily lives. Such as water, juice, milk, health products, medicine, tea, food, beverages, condiments, etc. may come into contact with us at any time, will be used in membrane separation technology.
With the rapid development of national economy, the application field of membrane separation technology will not only more widespread, and it will be more and more people understand and accept. According to preliminary statistics, in 2001 worldwide sales of the film and membrane modules has been close to 80 billion dollars, equipment and film project market already reached tens of billions of dollars, and every year is still 10% to 20% rate increase , showing broad prospects for this emerging industry.
