Briefly explain:
Nanofiltration (NF) film called Loose early reverse osmosis (Loose RO) film, is the beginning of the 80 s after the typical reverse osmosis (RO) composite film developed after the.
Details:
Nanofiltration is somewhere between ultrafiltration and reverse osmosis a membrane separation technology, its intercept molecular weight in the 200-1000 range, aperture for a few nanometers, so says nanofiltration. Based on the nanofiltration separation technology is superior characteristics, and its in pharmaceutical, chemical, biochemical, food industry and many other fields shows broad application prospect.
1. Nanofiltration membrane and the definition of the species
Nanofiltration (NF) film called Loose early reverse osmosis (Loose RO) film, is the beginning of the 80 s after the typical reverse osmosis (RO) composite film developed after the. Its precise definition so far, academia has not a unified explain, here are expressed as:
(1) NF membrane between RO and UF membrane between the desulphurization rate of NaCl in below 90%, almost all of the RO film solute has very high removal rate, but only to the specific NF film solute with high desulphurization rate;
(2) NF membrane mainly eliminate diameter for a nano (nm) or so solute particles, intercept molecular weight for 100 ~ 1000, mainly used for drinking water in the field from three bittern firedamp intermediates, peculiar smell, chroma, pesticide, synthetic detergents, soluble organic matter, calcium, and hardness composition and evaporation residue. Nanofiltration membrane of a great feature is a film with a charge of ontology. This is it in very low pressure still has high performance and intercept molecular weight desalination for hundreds of membrane can also be the important reasons for removing the inorganic salts.
2. Nanofiltration membrane application
(1) softening water treatment
2) the removal of harmful substance in drinking water
The traditional water treatment mainly through the flocculation, settlement, sand filter and chlorine was added to remove the water for the disinfection of muddy thing and bacteria, and for all kinds of solubility chemical removal from effect is very low. As the water pollution levels and all drinking water higher standard, can be all kinds of organic matter and removal of harmful chemicals "drinking water depth processing" increasingly attention by people.
A large industrial practice showed that the operation of the plant, nanofiltration membrane can be used for removing the river and underground water containing three bittern firedamp intermediates THM (chlorine was added the by-products for disinfection carcinogenic substance), low molecular organic matter, pesticide, peculiar smell material, nitrate, sulfate, fluorine, boron, arsenic and other harmful substances.