What is the difference between reverse osmosis membrane and ultrafiltration membrane?
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Update time : 2023-10-06 11:39:37
What is the difference between reverse osmosis membrane and ultrafiltration membrane?
Filtration principle
Reverse osmosis membrane: Reverse osmosis, also known as reverse osmosis, is a membrane separation operation that uses pressure difference as a driving force to separate from the solution. Because it is in the opposite direction of natural penetration, that is, under a certain pressure, water will penetrate from a low place to a high place in the opposite direction, so it is called reverse osmosis.
● Reverse osmosis is currently the most fine filtration technology, reverse osmosis membrane can block all dissolved no polar any relative molecular weight greater than 100 organic matter, the removal rate of bivalent ions in water up to 99.5%, the removal rate of univalent ions is also more than 95%.
● Reverse osmosis Because the aperture of the RO membrane is five millionths of the hair (0.0001 micron) can not be seen by the naked eye, bacteria, viruses are 5000 times his, so only water molecules and some of the mineral ions beneficial to the human body can pass, other impurities and heavy metals are discharged by the wastewater pipe.
Ultrafiltration membrane: ultrafiltration aperture can probably trap more than 0.1um of particles, remove organic matter, for most water, including seawater. After ultrafiltration, SDI (sewage index) can be reduced to 1 ~ 3. Ultrafiltration can remove bacteria and microorganisms from water 100 percent.
● A nominal membrane aperture of 0.03um can remove bacteria, viruses, particulate matter including colloids to protect subsequent process equipment such as reverse osmosis systems.
● High strength and chemical resistance of PVDF polymerized hollow fiber membrane filaments ensure a longer service life of membrane components.
● The hydrophilic PVDF fiber membrane filament is easy to clean and wet, so that it can maintain good performance for a long time. The external pressure structure can withstand higher influent suspended solids concentration and reduce the pretreatment process.
Application characteristics
The reverse osmosis membrane should have the following characteristics:
(1) It should have an efficient desalting rate at high flow rate;
(2) with high mechanical strength and service life;
(3) can function under low operating pressure;
(4) Resistant to chemical or biochemical effects;
(5) Less affected by pH value, temperature and other factors.
Ultrafiltration membranes should have the following characteristics:
(1) There will be no qualitative change in the ultrafiltration process, and it can operate stably at room temperature;
(2) The equipment is compact in structure, small in footprint and easy to operate;
(3) The ultrafiltration separation process is simple and the equipment is highly automated;
(4) can classify different molecular weight substances;
(5) Strong applicability to water quality and wide range of applications.
Application field
The wide application range of reverse osmosis membrane: chemical industry, metallurgy industry, food and beverage industry, seawater desalination industry, electronics industry, water treatment industry, medical industry, power industry and so on play an important role.
The wide application of ultrafiltration membrane is in the preparation of mineral water; Reverse osmosis pretreatment; Tap water purification treatment; Pretreatment of seawater desalination; Purification pretreatment of wastewater reuse; Remove colloids and bacteria from water; Concentration, purification and clarification in fermentation, enzyme industry and pharmaceutical industry; Fruit juice concentration and separation; Separation of soybean, dairy, sugar industry, wine, tea juice, vinegar, etc.
