Home water purifier commonly used water purification process

In the past few years, the growth rate of water purifiers in the household appliance industry has been particularly fast. Chinese consumers prefer water purifiers that are recyclable, cost-effective, reliable and have optimal filtration. Different water purifiers have different water purification effects. The ideal water purifier should be able to filter out impurities from the water for direct drinking. Therefore, consumers should be careful to purchase home water purifiers with high performance and cost-effectiveness based on the main needs of the family.

So, what are the common water purification processes used in our general home water purifiers? Let's take a look at some of the simplest and most common ones.
The first is filtration, so what are the filtration methods? Let's take a look together:

1, filtration
With pressure as the driving force, the process of removing particulate impurities from water by separating them through filter media, filter mesh, filter membrane and filter cartridge. According to the different filter materials, common filtration has the following types:

(1) Quartz sand filtration
Used in the front end of large-scale water purification equipment, quartz sand as a filter media, filtering to remove particulate impurities in the water with a diameter of ≥ 50μm. Quartz sand filter media life of 5 to 8 years, the use of the annual addition of 2% to make up for the loss.
(2) Multi-media filtration
Used in the front end of large-scale water purification equipment, anthracite, quartz sand, manganese sand as filter media, filtering water diameter ≥ 50μm granular impurities, filtration effect is better than a single quartz sand filter media, can improve the filtration rate. The life of the upper layer of anthracite is 1 to 2 years, and 6% of it is added every year. The life span of quartz sand in the middle layer is 5-8 years, and 2% is added every year. Lower manganese sand life of 3 to 5 years, the use of the annual addition of 4%.
(3) PP cotton filter
Installed in the front of the household water purifier and large-scale water purification equipment membrane filtration device front, filtration filtration water diameter ≥ 1μm ~ 10μm particulate impurities, inexpensive, subject to regular replacement, life expectancy is generally 3 ~ 6 months. (4) PE sintered cartridge filtration installed in the front of household water purifiers and large-scale water purification equipment membrane filtration device front, filtration filtration ≥ 1 μm ~ 10 μm diameter particulate impurities in the water, the price is more expensive than the PP, and therefore use less, need to be replaced regularly, life expectancy of generally 3 to 6 months. (5) Diatomaceous earth ceramic cartridge filtration
Large or small water purification equipment are useful, made of diatomaceous earth and binder sintered at high temperatures, filtration filtration water diameter ≥ 1μm ~ 10μm particulate impurities, need to be taken out regularly to scrub the surface, life expectancy is generally 3 ~ 5 years.
(6) Stainless steel filter
Installed in the home after the water meter on the main pipe (pre-filter), in all water points and the front of the water equipment, filtering out water diameter ≥ 50μm particulate impurities. Artificial or automatic backwashing can be used, life expectancy is generally 8 to 10 years.
(7) Stainless steel laminated (plastic laminated) filtration
Used in the front end of large-scale water purification equipment, by the stainless steel laminated or plastic laminated gap filtration, filtration of water diameter ≥ 50μm particulate impurities, can be manual or automatic backwashing. Stainless steel laminated life is generally 10 to 12 years, plastic laminated life is generally 8 to 10 years.
Today, the water purifier plays an important role in people's daily life, it appears to make people more and more direct way of drinking water from the tap, really for people's consumption of water to bring a safe and healthy protection. Water purifier of a variety of water quality treatment methods to show its purification of water quality of the high function, so the water purifier gradually won more and more people's favorite, and gradually become a household in the regular drinking water equipment.

2、Adsorption
Liquid, gas, solute, colloid or suspended matter adheres to the surface of the porous solid medium contacted or into its pores of the physical or chemical process. According to the different materials, common adsorption can be divided into the following categories:

(1) Granular activated carbon adsorption
Large or small water purification equipment are useful, large equipment installed in the quartz sand (or multi-media) filter, small equipment installed in the PP cotton filter; adsorption to remove colloids in the water, organics, residual chlorine, chromaticity, odor, odor, etc.; granular activated carbon particle size: large water purification equipment is recommended to choose 10 to 24 mesh, small household water purifiers are recommended to choose 20 to 40 mesh; activated carbon filters of large-scale equipment to be regularly Backwashing. Granular activated carbon or its filter element needs to be replaced regularly, otherwise it is easy to breed bacteria and produce nitrite. Life expectancy is generally 6 to 12 months.
(2) Sintered activated carbon cartridge adsorption
Used in small water purification equipment, sintered activated carbon cartridge is a mixture of activated carbon powder and binder molding, and then high-temperature sintering system. Generally installed after the granular activated carbon cartridge; for further filtration to filter out particulate impurities in the water, including granular activated carbon cartridge outflow of black charcoal powder, not only can filter out particulate impurities in the water ≥ 1μm ~ 10μm in diameter, but also further adsorption to remove colloids in the water, organics, residual chlorine, chromaticity, odor, taste, etc.; need to be replaced regularly, or else it is prone to breeding of bacteria and nitrite production. Life expectancy is generally 6 to 12 months
(3) Extruded activated carbon cartridge adsorption filtration
Used in small water purification equipment, extruded activated carbon cartridge is the activated carbon powder and binder (PE powder, etc.) mixed and heated, and then extruded with a screw extruder; generally installed after the granular activated carbon cartridge for further filtration of particulate impurities in the water, including granular activated carbon cartridge flow out of the black charcoal powder, not only filtering to filter out the particulate impurities in the water with a diameter of ≥ 1 μm ~ 10 μm, but also further adsorption to remove colloids, organics, and organic matter in the water. Remove colloid, organic matter, residual chlorine, color, odor, taste, etc.; cheaper than sintered activated carbon cartridge, but the performance and water flux is not as good as sintered activated carbon cartridge. It needs to be replaced regularly, otherwise it is easy to breed bacteria and produce nitrite. Life expectancy is generally 6 to 12 months.
(4) Activated carbon fiber adsorption filtration
Used in small water purification equipment, generally installed after the granular activated carbon cartridge for further filtration of particulate impurities in the water, both the filtering of particulate impurities in the water ≥ 1μm ~ 10μm in diameter, as well as further adsorption to remove colloids in the water, organics, residual chlorine, chromaticity, odor, taste and so on. The price is more expensive than sintered activated carbon cartridge, but the performance and water flux are better than sintered activated carbon cartridge. It needs to be replaced regularly, otherwise it is easy to breed bacteria and produce nitrite. Life expectancy is generally 6 to 12 months.
(5) zeolite adsorption: zeolite as the adsorption material, can remove colloids in water, organic matter, residual chlorine, color, odor, odor and so on;
(6) molecular sieve adsorption: molecular sieve as the adsorption material, to remove colloids in water, organic matter, residual chlorine, color, odor, odor, etc.;
(7) Macroporous resin adsorption: using macroporous resin as adsorbent material, removing colloid, organic matter, color, odor, odor, etc. in water, and it can be regenerated by alkaline solution.

3、Bactericidal, antibacterial
Physical or chemical methods to kill bacteria in the water or inhibit the growth of bacterial reproduction in the water process. Common bactericidal sterilization process is as follows:

(1) Ozone sterilization
Ozone has a broad-spectrum sterilization, sterilization speed 500 times faster than chlorine, sterilization decomposition into oxygen, there is no residual material, will not cause pollution to the water quality. But the ozone in the water not only cause the water has a bad taste, bad taste, more importantly, ozone has a strong oxidizing effect on the human esophagus, gastric mucous membrane are damaged, so to wait for the decomposition of ozone in the water before drinking; water purification equipment can be in the night every day at regular intervals (such as twelve o'clock in the middle of the night) with the ozone on the pure water tank and the box of pure water, and the outlet pipe system for a short period of time for the disinfection of the sterilization, not only to achieve the sterilization effect but also to achieve the effect of the sterilization. Will not affect the taste of water and cause adverse effects on human health. There is also the production of small ozone machines and ozone water products for drinking water sterilization.
(2) silver-carrying sterilization, bacteriostasis
Used in small water purification equipment, silver-carrying activated carbon, silver-carrying resin, silver-carrying PP cotton, etc.; the use of silver ions in the water should be careful to prevent excess silver ions, excessive silver ions are poisonous, tested and approved by the health permit can be used for drinking water equipment.
(3) Zinc-carrying sterilization, bacteriostasis
For small water purification equipment, zinc-carrying activated carbon, zinc-carrying resin, zinc-carrying PP cotton, etc.; use should pay attention to prevent the water from exceeding zinc ions, zinc ions are less toxic than silver ions, but zinc ions are very easy to dissolve in water - must be tested and approved by the health license can be used for drinking water equipment.
(4) KDF sterilization, antibacterial
KDF is a high-purity copper-zinc alloy particles for domestic large-scale activated carbon water purifier (central water purifier), placed in the activated carbon before the removal of residual chlorine in the water, heavy metals and bacteriostatic; appropriate to be placed in the bathroom and the laundry room, the water is used for bathing, laundry, because of the fear of zinc ions in the water exceeds the standard, not suitable for drinking.
(5) Bromine resin sterilization
Used in small water purification equipment, sterilization effect is good, but the taste of the water is not good, there is a bromine odor, and the water oxidation corrosive, the back of the pipe fittings to use oxidation-resistant materials such as PP, PE, can not be used for fear of oxidation of the POM (paraformaldehyde) and other materials, otherwise it will be corroded for a long time, resulting in water leakage.
(6) Iodine resin sterilization
Used in small water purification equipment, sterilization effect is good. In the nineties of last century was popular, but due to the poor taste of water, there is iodine odor, so now only used in special circumstances, such as war, plague, disaster relief.
(7) Graphene sterilization
New materials for small water purification equipment, some companies use graphene sterilization technology made of cartridges, placed in the water purifier. (8) Activated quantum silicon cartridge sterilization
New materials for small-scale water purification equipment, some companies use activated quantum silicon cartridge sterilization technology made of cartridges, placed in the water purifier;
(9) Low-pressure mercury lamp UV sterilization
Large or small water purification equipment are useful, with a wavelength of 200nm ~ 300nm low-pressure mercury lamp UV irradiation, kill microorganisms or make microorganisms inactive process; low-pressure mercury lamp UV sterilization device has over-flow, immersed in the two categories, is the most widely used water purification equipment in the sterilization technology; the defects are: not open that is to kill, but there is a delay; after a period of time, in contact with water in the Quartz glass casing surface will generate biofilm, it is a mixture of bacteria, bacterial corpses, bacterial secretions, such as a sticky layer, will block the transmission of ultraviolet light, reducing the sterilization effect. Industrial large-scale equipment can be used to automatically scrape the way (similar to car wipers) regularly removed. Domestic UV lamp life standard for 5000h, some imported UV lamp life can reach 10000h, need to be replaced regularly according to the instructions. Industry can also be based on the detection of 254nm light intensity to be replaced.
(10) LEDUV sterilization
Used for small water purification equipment, new materials, power saving, that is, kill; but the power is small, expensive, can not be used for large-scale water purification equipment.
(11) Photocatalyst sterilization
New technology for small water purification equipment, some companies use photocatalyst sterilization technology made of cartridges and water purifiers;
(12) Light energy targeting
New technology for small-scale water purification equipment, some enterprises use light energy targeting sterilization technology to make filter cartridges and water purifiers.
(13) Sterilization by heating and boiling
It is the most classic and commonly used sterilization method. A lot of campus drinking water equipment is the first inlet water heating and boiling, and then through the heat exchange into warm water for students to drink, and the inlet water into hot water through the heat exchanger, boiling energy-saving; campus drinking water equipment is also timed every day (such as 5:00 a.m.) automatically with boiling water immersion pipeline, faucet, in order to ensure that the total number of bacterial colony of the water is qualified. (14) Electric field sterilization
With high-voltage electric field or low-pressure electric field sterilization technology;
(15) ultrasonic sterilization technology with ultrasonic sterilization
So, the water purifier if only to achieve the effect of sterilization then the significance is not particularly large, but the specific ability to do which step is related to the filtration precision of the water purifier.
Sterilization is no problem at all, but heavy metals, some emerging pollutants, limescale, such as: ultrafiltration water purifier filtration precision is only 0.01, the substance it is completely unable to filter out. But RO reverse osmosis is not the same, the filtration accuracy of 0.0001 microns, normal water pressure water molecules can not pass, so this type of water purifier needs to be pressurized by the pump will be squeezed through the RO membrane, water molecules with a diameter of 0.0004 microns, need to be energized and pressurized in order to go through, then those pollutants will certainly be retained in front of the RO membrane with the wastewater together with the sewage so the filtration accuracy is high enough! Water purifier is not only able to filter bacteria, oh, but also filter out scale, viruses, colloids, heavy metals and other pollutants, the water can be directly drinkable it.

4, membrane technology
Home water purification equipment in the common types of membrane technology are reverse osmosis, nanofiltration, ultrafiltration, microfiltration, electrodialysis. Reverse osmosis technology is most commonly used in the production of pure water for drinking.

(1) reverse osmosis (RO): in the water inlet side of the membrane than the solution osmotic pressure applied to the outside world, only allows the solution of water and some components of the selective permeability, other substances can not pass through the process of being retained on the surface of the membrane;
(2) Nanofiltration (NF): Pressure-driven membrane separation process for removing divalent and above divalent polyvalent ions and organic matter with molecular weight above 200 in water;
(3) ultrafiltration (UF): pressure-driven, separation of water molecular weight range of hundreds to millions of organic matter, membrane pore size of about 0.005μm ~ 0.1μm physical screening process;
(4) Microfiltration (MF): pressure-driven, separation of particles in water from 0.1μm to 1μm process;
(5) electrodialysis (ED): ion exchange membrane as a separation medium, potential difference as a driving force, so that the water anion and cation directional migration and through the ion exchange membrane, so as to carry out the process of ion separation.

Now, we all roughly understand the most basic types of water purifier water purification process. Then, when choosing a water purifier, you must compare and understand more oh! After all, we install a water purifier for the sole purpose of drinking clean water!