The so-called household water purifiers is to tap water depth treatment of drinking water installations. Household water purification began in the 1950s, the 1970s became popular consensus continues today. Especially in the 20th century in the United States first discovered the existence of water disinfection by-product began as a family of self-protection devices, many American families to begin the installation and use 1, PP cotton filter water purifier: that is equipped with a variety of PP cotton Monocular filter water purifier, the general price of the machine Product parameters: Name: coway P-07QR water purifier brand: coway Model: P-07QR Category: water machine Item No: 07qr Color Category: White Operating principle: Reverse osmosis Filter: RO membrane using location: Terminal water purification effect: straight drink low, but relatively easy to plug the filter, replace the higher frequencies filtering precision is not very high, this is only for the initial filtered water, not drinkable. 2, the composite sintered activated carbon water filter: The main filter medium activated carbon rods. Carbon rods are usually fired by the different sizes of activated carbon powder and high temperature adhesive material is made. [2] features: Since the porous structure of the active carbon powder (it is estimated that 3 to 5 g of active carbon powder specific surface area equivalent to the size of a standard football field), activated carbon rod after firing a very dense, for tap water odor, odor, chlorine and volatile organic compounds and other pollutants with high removal efficiency, some manufacturers of carbon rods can even filter in accordance with US standards NSF53 spore cysts, and can retain the minerals in the water, without the use of microfiltration, ultrafiltration additional filter media.