Need a water purifier? Which water purifier is more suitable for your home?
I believe you will have the answer after reading it!
The following content comes from the good life APP user @ 丫丫丫丫丫丫丫丫丫丫丫丫丫𰶯𰶯𰶯𰶯2000
With the continuous improvement of people's material living standards, the pursuit of health is naturally higher and higher! The first important thing is domestic water.
The picture we are looking forward to is like this:
However, the reality is this:
All kinds of water purification equipment have mushroomed. Faced with the dazzling array of water purification products on the market, I believe most people are as embarrassed as I was at the beginning.
In addition, most sales consultants are in a hurry and don't know much about the principle and function of water purification system. They do their best to popularize it, and it has become a common practice to exaggerate its functions. In short, their own products are air in seconds, and all water problems can be solved by one machine.
In order to protect your wallet, this question will come to the science of water purification.
-0 1. Filtering method-
Common water filtration methods in the market include microfiltration, ultrafiltration, nanofiltration and RO (covering 99%). Corresponding to the following substances that may be contained in tap water, the filtration capacity is as follows:
If we imagine different impurities as fish with different sizes, different filtering methods are fishing nets with different pore sizes, which are expressed according to the pore size, as shown in the following figure:
-02. Water purification equipment-
(1) Pre-filter (pre-water purifier, waterway protector)
Filtering accuracy:1μ m-100μ m.
The household filtering equipment installed at the front end (so called the front end) of the household tap water main will filter out the large-particle impurities visible to the naked eye, especially the sediment and algae in the pipeline.
There are two kinds of pre-filters, one is backwashing, and the other is with filter element. Personally, it is recommended not to replace the filter element (essentially stainless steel metal filter) for backwashing. Turn the valve to backwash when it is dirty, and it will be clean after washing for a while. The service life is over 15 years, and the cost is very low. Replacing the filter element is relatively troublesome and the subsequent investment is high.
Advantages: it can protect the subsequent water purification equipment and waterways. There is no need for special after-sales service and filter element replacement (backwashing front), the filtering effect is intuitive and transparent, and the service life is long (up to decades).
Disadvantages: the accuracy is not high, and it can only be roughly filtered.
Purchase suggestion: The common precision in the market is about 40μm, the higher the precision, the better the filtration effect, but the easier it is to block, the greater the water pressure attenuation. On the positive side, I personally think it is enough to buy about 500 yuan made in China, and the positive side of buying more than 1000 yuan can only say that I am rich and willful.
(2) Ultrafiltration machine (the name on the market is confusing, such as what water purifier, direct drinking machine, etc. )
Filtering accuracy: 0.01μ m-0.1μ m.
Ultrafiltration machine is a device that uses ultrafiltration technology to purify water. Different from other water purification equipment, it uses ultrafiltration membrane in its equipment.
Generally, the multistage ultrafiltration installed under the kitchen as shown in the above picture is sold to families in the market. In addition to ultrafiltration membrane, PP cotton (the filtration accuracy sold in the market is generally 10-20μm, which is mainly microfiltration without sterilization) and activated carbon filter element (activated carbon has two functions of removing residual chlorine and improving taste) are added. Ultrafiltration can effectively remove harmful substances such as sediment, rust, bacteria and macromolecular organic matter in water.
Interrupt a question and answer: some people here may ask, since the ultrafiltration machine can remove sediment, what about pre-installation? It is true that the ultrafiltration machine can remove sediment, but its accuracy is higher than that of the pre-filter, which means that it is more likely to be blocked by sediment and greatly reduces the life of the filter element, so this hard work is still done by the pre-filter, after all, there is no need for consumables.
Advantages: it can completely remove bacteria, algae and other organic substances, and can be directly drunk in places with low metal ion content (which is why businesses basically sell it in the name of direct drinking machines), but it is still recommended to boil it for drinking. See the next article for reasons. No electricity is needed, and the ultrafiltration membrane needs a pressure above 0. 1Mpa to filter, which can basically meet the general household water pressure.
Disadvantages: Although the ultrafiltration machine retains minerals and trace elements beneficial to human body, it also means that heavy metal ions and calcium and magnesium ions cannot be filtered out, so there must be scale or scale, and there is still no way for heavy metals to exceed the standard. Replace the filter element regularly, and the replacement cycle of different filter elements is different, so you need to pay attention.
Purchase suggestion: Ultrafiltration membrane belongs to chemical fiber, which is very delicate and prone to problems. A fatal disadvantage of ultrafiltration membrane water purifier is that only one membrane filament breaks, and harmful substances such as bacteria will flow out through the break, which is equivalent to scrapping the whole ultrafiltration membrane. However, domestic related test reports show that the domestic ultrafiltration membrane water purifier can hardly be directly drunk. Therefore, it is better to buy imported brands, and domestic assembly is not at ease. ....
③ Reverse osmosis water purifier (RO machine)
Filtering accuracy: 0. 1nm- 1nm.
RO machine is a popular reverse osmosis filtration method in the world, which pressurizes raw water, filters it by physical principles, and then produces pure water (also called terminal water purification equipment) that can be directly consumed by human beings without adding any compounds.
Only the water treated by RO membrane is the real direct drinking machine! (Because only water molecules can penetrate the RO membrane, it is pure water molecule H2O after filtration)
Generally speaking, the RO machine has five filter elements, as shown in the following figure (example).
It can be seen that the difference between RO machine and ultrafiltration machine in filter element is almost that one uses ultrafiltration membrane and the other uses RO membrane. As mentioned above, PP cotton is used to remove suspended matter, activated carbon is used to remove residual chlorine and improve taste, and the key consumables are RO membrane or ultrafiltration membrane. The famous RO membranes are nothing more than Dow, GM, Han Shi and Toray, but it is said that at least two-thirds of the RO membranes of major brands on the market are fakes. Most of them are from Shenzhen.
The domestic RO membrane does adopt the same reverse osmosis technology as the American aerospace industry. However, their diaphragm quality, film rolling process and film layers are all shoddy, all in order to save costs. In this way, many water purifiers on the market will become large-scale in less than three or two months, and TDS will soar. Some reverse osmosis membranes are blocked or damaged.
Some large domestic enterprises claim to adopt American Dow membrane. This is true and false. They buy Dow membrane from America, and then process it into filter element by themselves. Its number of layers, film rolling process, etc. Nature is thousands of miles away from the original Dow. But they won't tell consumers that they rolled the film themselves, just vaguely saying that it is Dow film.
You ask me how to buy a reliable RO membrane? I don't know. Help yourself. The market is so chaotic. .....
Give a knowledge point: many merchants in the market use TDS pens to detect water, and draw the conclusion that the TDS value of water filtered by pure water machine is low, so the water from pure water machine is healthier. This is completely misleading!
1. What is TDS? TDS stands for total dissolved solids, and its main function is to tell you the content of conductive ions such as calcium, magnesium, sodium and potassium in water. In the national standard GB5749-2006 "Hygienic Standard for Drinking Water", the requirement for TDS is less than1000 mg/L. Because the water treated by RO machine has only water molecules and almost no conductive ions, the TDS value is naturally low, but it does not mean that the water with low TDS is good, and the water with high TDS is unhealthy. For example, the French chatterton water specially used by European royalty has a TDS as high as 1882mg/L, because it is rich in various beneficial minerals and trace elements.
But we don't have to worry that drinking pure water for a long time will lead to mineral deficiency. After all, drinking water only accounts for a small part of our access to minerals.
Advantages: among all water purification equipment, the only one that meets the standard of direct drinking is more direct than ultrafiltration.
Disadvantages:
(1) needs voltage, so reserve potential.
(2) Reverse osmosis may produce wastewater. In the past, the industry standard pure wastewater ratio was 1: 3. Now there are more and more pure wastewater ratios in the market, but it will still cause a certain waste of water resources, which is not very environmentally friendly and is not suitable for large-scale water use (so those who think that since the RO machine is so good, I can use RO membrane to purify the water all over the house, so it can be saved.
③ The water outlet speed is too slow! Therefore, in order to solve this problem, there are two schools in the market: one is the water storage type, just like the picture above, with a water storage bucket, which solves the problem of water outlet speed, but brings two problems, the first is that it takes up more space and is unfriendly to small houses, and the second is the problem of secondary pollution; Second, by increasing the pressure of water flowing through the RO membrane, but at the expense of the service life of the RO membrane, the cost of consumables will increase in the later period; As for which type is better, there has been a heated debate on the Internet. I don't want to be forced here. Let's choose according to our needs.
④ nanofiltration machine
Filtering accuracy: 0.0 1 micron-0.001μ m.
Through the filter element, the water purifier that can make water is called nanofiltration water purifier, and nanofiltration can remove micro-pollution. Nanofiltration is between ultrafiltration and reverse osmosis, and the pore size of the nanofiltration core is between 0.0 1-0.00 1 micron, which can filter out chemical pollutants such as antibiotics, hormones, pesticides, petroleum, detergents, heavy metals and microcystins. While mineral ions smaller than this pore size can pass through. The market share is small, so I won't go into details.
-03. Miscellaneous items-
① Water softener
Only responsible for one thing, that is, reducing the hardness of water, that is, reducing calcium and magnesium ions in water, regardless of whether other impurities should exist or not. Hard water, the most intuitive thing is that boiling water is easy to scale, which is not good for water heaters, plumbing pipes and dishwashers; When taking a bath, mirrors and faucets will leave water stains when they are dry, and towels and clothes will become hard when washed many times. Drinking too hard water for a long time is not good for your health. It is said that the bald head of the British prince is also caused by hard water quality, so he is afraid after careful consideration.
The working principle of water softener is ion exchange technology, which replaces calcium and magnesium ions in water with sodium ions (so the special salt for water softener should be added regularly, which is actually medium salt), and the water with higher sodium ions (the harder the water is, the higher the sodium ion content is), which is why some people say that soft water can't be drunk (I think even if the sodium ion content is higher, it will not reach the level that people can perceive, and the total sodium ion intake of soft water drunk in one day is not as good as one mouthful).
As for the central water softener, it is only larger in capacity, and there is no difference in essence.
At present, the water softener market is really profiteering. Unlike RO machines and ultrafiltration machines, there are no high-tech technical barriers on consumables (to put it bluntly, it is medium salt, a big bag 10 yuan). The core technology is only the algorithm and stability of the control module, but the price is too high, so there are many DIY on Taobao now, so you can try it if you like to toss.
② Central water purifier
The main difference is that the treatment capacity is large, which can be divided into ultrafiltration membrane and non-ultrafiltration membrane:
A. The central water purifier without ultrafiltration membrane can effectively remove chlorine, rust, heavy metals, viruses, algae and suspended solids from water, making the treated water clear and clean. Mainly used for treating domestic water. Generally installed next to the water inlet pipe. Mainly used in families, schools, hotels, hotels and so on.
B. The central water purifier with ultrafiltration membrane can sterilize and achieve the above effect. Generally used for domestic water, the main purpose is direct drinking.
③ net kettle, cleaning bucket, etc.
Where the filtration pressure is not high, the filtration accuracy must be very poor. Such as kettle, cleaning bucket, desktop integrated machine, intelligent integrated machine for filtering and heating, etc. It is claimed to be drinkable directly. Is there a high-precision filter material and enough pressure? This is bullshit!
-04. Construction of water purification system-
To put it bluntly, the water purification system is a set of water treatment system built by choosing different water purification equipment according to your family needs. Borrow a promotional picture of a domestic brand:
Knowing the accuracy, principle and use of the above water purification equipment, the water purification system will be much simpler. We roughly divide waterways into three ways:
① Direct drinking water road: it needs the most thorough filtration.
② Kitchen waterway: general filtration, regardless of the problem of soft and hard water (varies from person to person).
③ Shower and laundry waterway: Soft water is needed.
The above is just a sign, and the specific layout depends on everyone's needs. For example, the navigation chart of my home (see the picture below) is slightly different from the above picture. Interested friends can study it carefully.
There is a lot of content, so let's digest it slowly.