Drinking water health has become a concern of most people. At present, newly renovated families will basically consider buying water purifiers, but after all, there are still a few people who buy water purifiers. Most people will choose to boil tap water for drinking, or buy water from self-service water vending machines in communities (after all, it seems healthier).
The water from the water vending machine in community 01 is not a national livelihood project, so the water quality safety should be treated with caution.
The author’s drinking habit is to buy bottled water directly as drinking water. Recently, because bottled water merchants can’t deliver it, I began to consider direct drinking water in the community. Is direct drinking water really healthy and safe? With the convenience of work, the author decided to targetCommunity self-service water vending machine water, tap water, water purifier water, mineral water and purified water.A comprehensive comparative test was carried out for this kind of water source.
First of all, let’s talk about the self-service drinking fountain in the community. Many residents who buy it think that this is a national livelihood project, but it is not. This kind of self-service drinking water equipment is basically.Individual contracted business,So whether it can meet the standard of purified water,It all depends on the purification ability of the machine itself and the maintenance level of the equipment by the contractor in the later period..
It seems that these self-service drinking water equipment in the author’s community have been used for a long time, and the bottom has begun to rust. As for whether it is maintained or not, can the equipment still purify water? Let’s ask a question first!
The water purification principle of residential drinking fountains is similar to that of domestic water purifiers.
The purification principle of the equipment is marked on the self-service drinking fountain in the community. It seems that there are as many as 10 items, but in fact there may be only five kinds of filter elements and purification equipment involved (according to the analysis of the purification process marked by the equipment), which is probablyPP filter element, compressed activated carbon filter element, RO reverse osmosis filter element, resin filter element, UV lamp, their principles are no different from those of household RO water purifier..
The above picture shows the internal structure of a dismantled self-service water selling device in a residential area on the network. It can be seen that several filter elements are built in, which are much larger than the household water purifier. Judging from the color of the filter elements (clean PP filter element is white), it should have been used for a long time (judging from the color, it has reached the scrapping standard), while the filter elements of household water purifiers generally need to be used for six months to one year before the color of the PP filter element can reach the color in the above picture.
So,The self-service water vending machine in the community is the same as the household water purifier (large household water purifier)In the popular words, it is to share water purifiers, which are all worn-out products that need regular maintenance and replacement. If you observe that no one has changed the filter element of the water vending machine for a long time, please don’t pick up the water, and the water quality may not be as clean as tap water.
Provide weekly water quality inspection report of automatic water vending machine.
The water quality test report was posted on the water vending machine, and the test items included PH value, conductivity, turbidity and total dissolved solids, and the time for replacing the filter element was marked.Of course, I didn’t see any words of national institutions from the test report, so the test report should be the result of the contractor’s independent testing and is not authoritative..
Five tests prove that the water quality of the water dispenser in the author’s community is acceptable.
From left to right: TDS pen, mineral pen, PH reagent, residual chlorine reagent and water quality electrolytic tester.
Next, we began to enter the actual measurement link. There are five items in this test.TDS value (total dissolved solids), mineral content, PH, residual chlorine content and electrolytic color of water quality.Through these five tests, we can roughly judge the water quality.
There is no doubt that tap water has the highest TDS value, and pure water is 1 mg/L.
TDS, also known as total dissolved solids, is measured in milligrams per liter (mg/L), which indicates how many milligrams of dissolved solids are dissolved in one liter of water. The higher the TDS value, the more dissolved substances are contained in the water. The function of the water purifier is to reduce the dissolved substances contained in the water. According to the measured results, the TDS content in tap water is the highest, and the lowest is the bottled pure water sold in the market, while the water from the self-service water vending machine in the community.TDS value is 62.Compared with tap water, it is indeed purified water, butThe measured value of the author is nearly twice as high as that of the water quality test report posted on the water vending machine..
Mineral content of tap water is still the highest, and pure water is 0.
From the results of mineral content, tap water is still the highest, and pure water is 0ppm.The water in the residential water vending machine is 50%, is still the second highest, but from the above two results, drinking water in the water vending machine in the community is better than drinking tap water.
Electrolytic process
Electrolytic test of water quality Pure water has almost no impurities. The color of water in the water purifier is a bit unexpected.
After the water quality is electrolyzed, some ions will be replaced, which will lead to the discoloration of the water source. We can judge the impurities that may be contained in the water quality through the approximate color.
After the electrolytic test, an interesting phenomenon was found. After the test, there were almost no impurities in the purified water, and the color could not be electrolyzed. However, the electrolytic color of mineral water and water in the community water vending machine was light yellow, which showed that there were fewer impurities in the water quality, while the purified water in tap water and water purifier was yellow.
The author also consulted the manufacturer of the tester. According to the description of the staff,Transparent color and yellow are safe water quality, but the lighter the yellow color, the purer the water quality..
Supplement:
The purified water of the purifier tested by the author comes from a commercial RO water purifier. Why is the impurity content of electrolysis higher than that of the water sold in the community?
I guess there are two reasons. First, the function types of the two water purifiers are different, and the water quality is different. Second, the filter element in the commercial water purification has not been replaced for a long time, which has caused a certain impact on the water quality. Here is also a reminder for everyone.If you are using a water purifier at home, be sure to pay attention to the replacement time of the water purification filter.The replacement cycle of PP cotton filter is about 6 months, activated carbon is about 1 year, and RO filter is 2-3 years, depending on the specific water quality.
The PH values are all within the national safety standards.
China’s national standard "Hygienic Standard for Drinking Water" GB5749-2006,The PH value in cities and towns should be between 6.5 and 8.5.,The countryside should be inBetween 6.5 and 9.5, this standard is a conventional limit indicator. From our measured results, except pure water in five different water samples, the other test waters are all weak acid or weak alkaline water, and the PH value of pure water is more alkaline (the reagent can’t reflect the specific value).
In addition, here is a little knowledge for everyone. Don’t be too superstitious about people drinking weak acid or weak alkali water. It is scientifically certified that as long as the water that meets the national standards is a good water source, weak acid and weak alkali will not have a positive or negative impact on the human body, and there is no therapeutic effect.
Residual chlorine test only tap water contains residual chlorine.
In the residual chlorine test, except tap water contains residual chlorine, other samples are transparent and almost contain no residual chlorine. All meet the national standards and regulations, and the residual chlorine content of the factory water stipulated by the state is ≥ 0.3mg/L。
Summary:
After the above five tests, the water quality of the self-service water vending machine in the author’s community should be no problem, and the water sold can be sure to be sold after purification. Because individuals can’t test the number of colonies in water samples, there is no way to answer whether the colonies in water sources exceed the standard.
If everyone is also buying water from the self-service water vending machine in the community,I suggest you buy a TDS test pen.The price is tens of yuan, which is very cheap. You can get a general idea of the working situation of the water purifier in the community by comparing the regular water test with the domestic tap water value. If the value is too high, I suggest you drink it carefully.
03 Little Eggs: Who is more cost-effective in drinking water at home?
Especially for many young people, it is impossible to drink boiled tap water directly. Therefore, no matter which way you choose to drink water, there is a cost. My colleagues have also calculated before.How to drink water is more cost-effective (click for details)With the help of colleagues’ calculation results, the author simply tells you the advantages and disadvantages of various drinking water.
Remarks: Calculated according to personal drinking water 1.5L/ day and domestic drinking water 5L/ day.
RO water purifier:
Advantages:Take it with you, there is no time cost and labor cost, and the water quality is the safest and healthier if the filter element is replaced in time.
Disadvantages:The cost of water use is slightly more expensive. The cost of water use per day is about 2.5-about 4.1 yuan (see the brand price of water purifier).
Community self-service water vending machine:
Advantages:The price is cheap, and the price per liter of water in the author’s community is about 0.2-0.3 yuan.
Disadvantages:The purification effect and safety of the water source are not guaranteed, and whether the water can be drunk healthily depends on the contractor’s conscience.
Barreled water:
Advantages:Suitable for families in single dog, each liter is about 1.3 yuan, and the quality of regular water source is acceptable.
Disadvantages:Drinking water for more than three people is not cost-effective, and some unscrupulous merchants shoddy it.
Bottled water:
Advantages:Water quality is guaranteed.
Disadvantages:The cost of drinking water is too high, and the price per liter is about 2.6 yuan.
From the above analysis, if it is a family of three, it is very necessary to buy a reliable RO water purifier, with comprehensive cost and convenience.The cost performance of choosing a water purifier is still relatively high., of courseThe self-service water vending machine in the community is a good choice for users who are cheap in pure plan and relatively recognized in the water quality of the water vending machine in the community.. For all of youFor single dog, bottled water is a good choice., andLocal tyrants who care about quality and don’t want to install water purifiers can choose to drink bottled water.