I remember that there was a public service advertisement about water, the slogan was like this: "if water resources are wasted arbitrarily, then the last drop of water on the earth will be our tears." Nowadays, people pay more and more attention to drinking water. Water purifier, water softener, water purifier and other water processors are more and more coming into people's life, and the treatment technology is more and more "superb", which also leads to various opinions about water. For example, the treated water is magical. If so, consumers will doubt it. So, how much is the technology content of the water processor? Can the water purifier guarantee the function of "water purification"? What kind of drinking way is healthy and safe? Let's explore the secret of the water processor.

Does tap water need to be purified again

With the increase of various water processors on the market, people can't help but wonder: "why do families purify tap water? Can't our tap water meet the drinking water standard?" the answer is No.

According to the water nutrition experts of Beijing Institute of public health and drinking water, in 2007, China issued the latest "Hygienic standard of drinking water of the people's Republic of China", which is in line with international standards. The number of water quality testing standards increased from 35 to 106. In big cities like Beijing, Shanghai and Guangzhou, the traditional processing technology of tap water has also been reformed, and the pretreatment and advanced treatment procedures have been added. As a result, the water quality has been greatly improved. It can be said that the water just coming from the waterworks is clean and safe.

However, in the whole country and even all over the world, there are unsafe factors in tap water, that is, it is polluted from time to time, and secondary pollution is a very important reason; In some areas, the water supply network and domestic sewage discharge network are in parallel, and some of them are in disrepair for a long time. The penetration rate of some networks is as high as 20% ~ 40%, which causes pollution to the water supply network.

In addition, there are many high-rise buildings in big cities, and the water supply of many small high-rise buildings is from the top to the bottom. Due to the poor management of the water tank, a large number of bacteria, cyanobacteria and green algae breed in the water tank, resulting in rust, red insects, turbidity, water scale and peculiar smell in the tap water, which makes the quality of domestic drinking water substandard. Boiling water can only kill bacteria and parasites and other pollutants in tap water, but can not remove sediment, rust, chemical pesticides, heavy metals and other pollutants in water. Therefore, if your tap water is polluted, it is necessary to install a water processor.

Purification of tap water by filtration technology

Water purifier is mainly used for drinking water purification of tap water. It can retain minerals beneficial to human body, but can not remove alkali and scale.

Water purifier uses filtration technology to separate particles from water through semi permeable materials. Its core component is filter element. Different models have different filter element combinations, ranging from primary filter element to nine filter elements. Among them, the microfiltration type uses the filter membrane with pore size of 0.02 μ m to 10 μ m as the medium to filter water, which can remove all kinds of impurities, rust, sediment, odor, residual chlorine, some heavy metals, etc. visible to the naked eye. At present, the most common microfiltration type water purifier in the market uses ppcotton filter element and activated carbon filter element. Its technology is relatively mature and widely used, but needs to be improved Timely cleaning, service life of 3 ~ 18 months.

The ultrafiltration type uses ultrafiltration membrane or nanofiltration membrane filter element. It uses the membrane with pore size of 0.001 μ m to 0.2 μ m as the medium to filter the water. It can remove bacteria, viruses, Escherichia coli and other harmful macromolecular organic matter in the water. However, experts from Beijing Institute of public health and drinking water think that if there are only ultrafiltration membrane filter elements, but no PP cotton filter elements and activated carbon filter elements in the ultrafiltration type water purifier, it can not remove the peculiar smell and residual chlorine, which is easy to block and shorten the service life of the membrane. It is suggested that the combination of these three filter elements be used.

In addition, if the quality of water purifier is not up to standard, high-quality water may also be polluted. Because the basic working principle of the water purifier is to purify the water quality through the built-in filter element, the quality of the filter element is directly related to the water quality and the service life of the water purifier.

Softened water cannot be drunk directly

Water can be divided into soft and hard. The hardness of water is also called salinity, which refers to the content of calcium salt and magnesium salt dissolved in water. The hardness with more content is higher, and vice versa. Soft water includes rain water, snow water and purified water, while hard water includes mineral water, tap water, surface water and groundwater in nature.

Experts from Beijing public health drinking water research institute believe that the working principle of water softener is to use sodium ion to exchange calcium and magnesium ions in water, so as to reduce the hardness of water, but it will increase the content of sodium in water, and it does not remove harmful substances such as bacteria and viruses; In addition, the water softener uses polymer resin and other filter materials, which will affect the water quality, so it is recommended not to drink softened water. If you want to drink, you need to go through a water purifier with reverse osmosis membrane.

Although the softened water can not be directly drunk, it is very good as domestic water. It can remove the alkali and scale, and better avoid the scaling problem of water pipes, taps and wading equipment. At the same time, it is softer and more comfortable than ordinary tap water for bathing and washing clothes. Long term bathing with soft water has skin beautifying effect, and washed clothes are cleaner. However, the use cost of water softener is relatively high. The market price of water softener that needs to add salt ranges from more than 1000 yuan to 4500 yuan, and the average monthly salt is 200-300 yuan. The salt free water softener completely eliminates calcium and magnesium ions in the water through electrolysis, which is more convenient, more space-saving and more expensive.