Author: Site Editor Publish Time: 2022-08-23 Origin: Site
1、The basic principle of microfiltration (MF)
Microfiltration membranes are capable of retaining particles between 0.1 and 1 micron. MF membranes allow large molecules and dissolved solids (inorganic salts) to pass through, but will retain suspended matter, bacteria, and large molecular weight colloids. Microfiltration is the world's first membrane technology to be developed and used with natural or synthetic polymeric compounds as membrane materials. For microfiltration membrane, its separation mechanism is mainly sieving and retention.
2、The application of microfiltration membrane
(1) Water treatment industry: the removal of suspended matter, tiny particles and bacteria in water.
(2) Electronics industry: semiconductor industry ultra-pure water, integrated circuit cleaning water terminal treatment.
(3) Pharmaceutical industry: medical pure water to remove bacteria, remove pyrogen, drug sterilization.
(4) Medical industry: removal of bacteria in tissue fluids, antibacterial agents, serum, plasma proteins and many other solutions.
(5) Food industry: removal of suspensions, microorganisms and odour impurities, yeast and moulds in beverages, wine, soy sauce, vinegar and other foods, clarification and filtration of fruit juices.
(6) Chemical industry: the filtration and clarification of various chemicals.
1. Ultra-filtration (UF) principle
Ultra-filtration (UF) is a kind of membrane separation technology that can purify and separate solutions. Ultra-filtration membrane system is an ultrafiltration membrane filament as the filtration medium, the pressure difference between the two sides of the membrane as the driving force of the solution separation device. The ultrafiltration membrane only allows the solvent (such as water molecules), inorganic salts and small organic molecules in the solution to pass through, while the suspended matter, colloids, proteins and microorganisms in the solution and other large molecules are retained, so as to achieve the purpose of purification and separation.
2、The application of ultrafiltration membrane
The application of ultrafiltration membrane is extremely wide, basically the industries involved in filtration can use filtration equipment, the basic filtration industries are as follows.
Pure water and ultrapure water preparation process as reverse osmosis pretreatment and ultrapure water terminal treatment; industrial water for the separation of bacteria, heat sources, colloids, suspended impurities and macromolecular organic matter; drinking water, mineral water purification; fermentation, enzyme preparation industry, pharmaceutical industry concentration, purification and clarification; juice concentration, separation; soybean, dairy, sugar industry, wine, tea juice, vinegar, etc. separation, concentration and clarification. Purification and recycling of industrial and domestic wastewater; recycling of electrophoretic paint.
1. Nanofiltration (NF) principle
Nanofiltration (NF) is a new molecular level membrane separation technology, is currently one of the world's membrane separation field research hotspots. NF membrane pore size in more than 1nm, generally in 1-2nm; solute retention performance between RO and UF membrane; RO membrane almost all solutes have a high rate of removal, but NF membrane only for specific solutes with a high rate of removal. NF membrane can remove divalent and trivalent ions, organic matter with Mn≥200, as well as microorganisms, colloids, heat sources, viruses, etc.
2. Nanofiltration membrane in the application of water treatment
Nanofiltration technology can remove most of the Ca, Mg plasma, so desalination is the most used area of nanofiltration technology. Membrane water treatment technology is similar to conventional lime softening and ion exchange process in terms of investment, operation and maintenance and price, but has the advantages of no sludge, no regeneration, complete removal of suspended matter and organic matter, easy operation and area saving, etc. There are more application examples. Nanofiltration can be used directly for groundwater, surface water and wastewater softening, but also as a pre-treatment for reverse osmosis, solar photovoltaic desalination devices, etc.