1. Household water purifiers can be divided into ultrafiltration type and RO reverse osmosis type according to different filter membranes.
2. "RO" means reverse osmosis. RO reverse osmosis membrane can filter particles with a diameter of 0.001 micron or even smaller. The water passing through RO membrane is only H2O, which is pure water. RO reverse osmosis water purifier has the characteristics of high filtration precision, reaching the standard of direct drinking water, good water quality and taste, but it also has the disadvantages of low water output, slow water output, and large waste water volume. The cost of replacing the filter element is also higher than that of ultrafiltration.
3. Except RO reverse osmosis water purifiers, most of them are ultrafiltration water purifiers. The ultrafiltration membrane of the ultrafiltration water purifier has a diameter of 0.1 μ m and a pore diameter larger than the RO membrane, which can intercept bacteria, colloid, virus and other impurities in the water. The ultrafiltration water purifier has the advantages of fast water outflow, large water outflow and low wastewater rate. However, due to the low filtration accuracy, it is not recommended to drink directly because it cannot completely filter viruses and some heavy metal ions.

From the filter element structure, the water purifier can be divided into three types: single-stage filter element water purifier, single-stage multi-layer (composite filter element) water purifier and multistage filter element water purifier.
There is only one filter material (such as polypropylene cotton or ceramic filter element) in the filter cartridge of the single-stage water purifier. This water purifier can only play a pretreatment role and has a relatively simple role in improving water quality. Therefore, the single-stage filter element water purifier cannot be used for direct drinking, such as single-stage ceramic faucet water purifier.
Single stage and multi-layer water purifier refers to a filter cartridge or filter element, which is composed of a variety of filter materials and distributed in the filter element step by step. Raw water can remove different kinds of harmful substances through the filter materials at all levels in the filter element. Many foreign brand water purifiers use this single-stage and multi-layer water purifier. The filter element is not suitable for places with poor water quality.
Multi stage water purifier is a water purifier composed of multiple filter elements. Generally, progressive filtration is adopted. The first stage uses PPcotton filter element to filter sediment and rust, the second stage uses granular activated carbon filter element to further absorb impurities and odor, the third stage UF ultrafiltration membrane or RO reverse osmosis membrane filter element completely filters out harmful substances, and the fourth stage uses post carbon rod filter element to absorb residual chlorine and odor to improve taste.

From the perspective of all qualified and qualified, the more filter elements, the more impurities will be filtered, but in real life it is not necessarily.
Some water purifiers advertise multistage filter elements for publicity. In fact, adding more layers of PPcotton filter, more activated carbon filter and ultrafiltration filter will be called six or seven levels of filtration, but the effect is the same as that of one layer, and the cost is increased. Therefore, the statement that the more filter elements, the better filtration is only in theory.

The water purifier is the same as the air purifier, and the replacement time of different filter elements is different. The replacement time of ultrafiltration membrane is generally 24 or 36 months, while the replacement time of RO reverse osmosis membrane is generally 12 months. Generally, mainstream water purifier brands will give the service life of the filter element of the water purifier or suggest the replacement cycle.
However, because the water quality in different regions of China is different, the replacement cycle should also be judged by the water quality in different regions. The time given by the manufacturer is only a reference cycle. Moreover, the actual service life of the filter element is also closely related to maintenance.

Since the replacement of filter element requires self judgment more often, how to determine the replacement is particularly important.
The replacement of the most important ultra filter element and RO reverse osmosis membrane of the water purifier can be observed from the water yield. If the water yield is greatly reduced or no water is produced, the filter element should be replaced. When it is found that the taste of the water produced by the drinking water purifier is not as good as before, it is necessary to consider replacing the composite filter element.
The core of the water purifier is the filter element, so the replacement of the filter element is related to the health of drinking water, so you must pay attention to the condition of the filter element.

First, it is clear that different regions have different standards for selecting water purifiers due to different water quality. If the water quality in some places is good, select single-stage and multi-layer water purifiers. If the water quality in some places is poor and there are many impurities, you need to select multi-stage filter water purifiers.
Due to the vast territory of China and the responsible geological structure, the water quality in different regions is different. The water hardness in western China is high, that is, the calcium and magnesium ions in the water are high, which is easy to produce scale. In this case, the resin filter element with ion exchange or KDF filter element water purifier should be selected.
In some areas, there are many residual chlorine in the water and there is obvious odor. At this time, the household water purifier with more activated carbon load can be selected.
For some friends who only want to talk with "pure water" because of their high requirements for water quality and safety, RO RO water purifier should be your choice.

RO reverse osmosis water purifier adopts the internationally popular reverse osmosis membrane technology to filter raw water and produce pure water without adding any compound. RO reverse osmosis membrane can filter particles with a diameter of 0.001 micron or even smaller, and the water passing through RO membrane is only H2O. Therefore, RO reverse osmosis water purifier is also called household water purifier. The produced water can meet the quality requirements of laboratory pure water, and no minerals will be left in the water filtered by RO water purifier.
Other types of water purifiers purify water quality through multistage filtration, which can absorb residual chlorine in water to remove odor and reduce the content of calcium and magnesium ions in water. However, due to the relatively large pore size of the filter membrane, they will not filter all minerals in water, but also cannot completely filter bacteria in water.

First of all, the barreled water mentioned here is not the bottled water below 5 liters that we bought from the supermarket, but the 19 liter barreled water on the water dispenser.
The biggest problem with this kind of large barreled water is that it is impossible to determine the true or false brand, the source of water and the treated purified water. And we all know that these barrels can be reused, so plastic aging and harmful chemicals may occur during repeated use.
Another problem lies in the water dispenser. Most families seldom clean the water dispenser and do not clean it once a month or even a year, which is very easy to breed bacteria. Previously, an expert report showed that under normal temperature, the number of harmful bacteria in the water dispenser was 0 on the first day, but it climbed to 8000 on the tenth day.
The water filtered by the water purifier can ensure the water quality as long as the water purifier is qualified and can achieve the nominal filtering effect, and can avoid the secondary pollution in the water storage process.
At this time, please look up to see if you are drinking large barrels of water in your office. Unfortunately, our company was hit.