Water treatment technologies, such as pre-Shen, coagulation, clarification, filtration, softening, and disinfection. Currently used for water filtration and purification of the use of membrane separation technology, membrane separation technology is usually divided into microfiltration, ultrafiltration, sodium filtration, reverse osmosis four major categories. 

 An ultrafiltration (UF): filtering accuracy 0.001-0.1 microns, belonging to one of the twenty-first century high-tech. A differential pressure membrane separation technology to filter the water, rust, sediment, suspended solids, colloids, bacteria, organic molecules and other harmful substances, and to retain some of the mineral elements beneficial to humans. The core components of mineral water, mountain spring water in the production process. The water recovery rate of up to 95% by ultrafiltration, and easy to wash and backwash, not easy to plug the relatively long service life. 

 Ultrafiltration pressure does not require power, and only rely on water pressure can be filtered traffic, use of low-cost, more suited to a comprehensive family drinking water purification. Future drinking water purification will be ultrafiltration technology-based, and combined with other filter materials, in order to achieve a wide range of processing a more comprehensive way to eliminate pollutants in water. 

 2, microfiltration (MF): filtering accuracy of 0.1-50 microns, the common variety of PP filter, activated carbon filters, ceramic filters belong to the microfiltration areas for simple coarse filtration, filtered water large particles of sediment, rust and other impurities, but can not remove the water of bacteria and other harmful substances. The filter is usually not clean, disposable filter material, the need for frequent replacement. 

 ① PP cotton core: the coarse filter is generally used for less demanding removal of water, sediment, rust and other particulate matter. 

 ② activated carbon: the elimination of heterochromatic and smell of the water, but can not remove bacteria, sediment, rust removal is also very poor. 

 ③ ceramic filters: minimum filtration precision 0.1 micron, typically flow is small and difficult to clean. 
 3, reverse osmosis (RO): filtering accuracy of 0.0001 micron, is the differential pressure developed in the United States in the early 1960s a super-high-precision use of membrane separation technology. Can filter the water, almost all of the impurities (including harmful and beneficial), and only allows water molecules to pass through. That is in the process of reverse osmosis membrane system for water, waste by nearly 50 percent more than tap water. This is unacceptable to the average family. Generally used for pure water, industrial ultra-pure water, medicine and manufacturing of ultra-pure water. Need pressure reverse osmosis technology, power, flow, water use is low, is not suitable for drinking water purification. 

 Sodium filtration (NF): filtering accuracy between ultrafiltration and reverse osmosis desalination rate is lower than reverse osmosis, is also a need to power the pressurized membrane separation technology, the water recovery rate is low. That is in the process of using the sodium membrane of water, it will certainly waste of nearly 30 percent of tap water. This is unacceptable to the average family. Generally used for industrial pure water production.