Automatic Intelligent Immersed Soft Flatsheet MBR Membrane Bioreactor Online Cleaning
Membrane liquid separation technology can generally be divided into four categories based on different operating pressures and the average pore size of the membrane used: microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO), and their filtration accuracy is increasing in the above order.
Microfiltration (MF)
Microfiltration can intercept particles between 0.1 and 1 micrometer, and the microfiltration membrane allows large organic molecules and soluble solids (inorganic salts) to pass through, but can block the passage of suspended solids, bacteria, some viruses, and large-scale colloids.
Ultrafiltration (UF)
Ultrafiltration can intercept particles and impurities between 0.002 and 0.1 microns. The ultrafiltration membrane allows small molecule substances and soluble solids (inorganic salts) to pass through, but it will effectively block colloids, proteins, microorganisms, and large molecule organic matter.
Nanofiltration (NF)
Nanofiltration is a special and promising type of separation membrane, named after its ability to retain substances of approximately 1 nanometer (0.001 micrometer) in size. The operating range of nanofiltration is between ultrafiltration and reverse osmosis, with a molecular weight of approximately 200-400 for organic matter and a ability to retain soluble salts of 20-98%. The removal rate of monovalent anionic salt solutions is lower than that of high valent anionic salt solutions, such as sodium chloride and calcium chloride, which have a removal rate of 20-80%, while the removal rate of magnesium sulfate and sodium sulfate is 90-98%. Nanofiltration membranes are generally used to remove organic matter and chromaticity from surface water, remove hardness and radioactive radium from well water, partially remove soluble salts, concentrate food, and separate useful substances from pharmaceuticals.
Reverse Osmosis (RO)
Reverse osmosis is the most precise membrane liquid separation technology, which can block all soluble salts and organic matter with a molecular weight greater than 100, but allows water molecules to pass through. The desalination rate of cellulose acetate reverse osmosis membrane can generally be greater than 95%, and the desalination rate of reverse osmosis composite membrane is generally greater than 98%. They are widely used in seawater and brackish water desalination, boiler feedwater, industrial pure water and electronic grade ultra pure water preparation, drinking pure water production, wastewater treatment and special separation processes. The use of reverse osmosis before ion exchange can significantly reduce operating costs and wastewater discharge.
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