Water is the source of life, and if a person leaves food, he can survive for about seven days, but if he does not ingest any water, he can only survive for three days. In addition, the main component of the human body is water, and the proportion is as high as 70%. Each example shows the importance of water to people.
Doctors recommend that people should consume at least 1,500 milliliters of water a day to promote normal life activities such as human metabolism, so almost every family is inseparable from drinking water.
When we are thirsty outside, we usually buy bottled water in the store, but because they are all produced goods, they must be marked with various types of production information, including shelf life.
At this time, many people are very confused, the water on the earth has existed for billions of years, but never heard of the expiration of the word.
As some brand slogans for mineral water say, they are just "nature's porters", so why does the water just change a container and pack it, why does it become easily "bad"?
The planet we live on can also be called a "water balloon" in a sense.
When the astronauts first went into space to see the original appearance of the earth, they found that the earth was actually a "blue" planet. That's because only twenty-nine percent of the earth's terrestrial environment is covered with water.
Despite this, water conservation is constantly being advocated internationally, because not all water can be used by humans, only freshwater resources.
The reserves of freshwater resources are very scarce, accounting for only about three percent of the total water resources, not only that, two-thirds of which are distributed in glaciers and saline lakes, and cannot be used by us.
The rest of the freshwater that comes from rivers and some freshwater lakes that we can use is only about one percent of the poor total water resources. Their main forms of existence are surface water, groundwater and natural precipitation.
There is no conclusive theory on the origin of water, and there are two more mainstream views.
One: long before the birth of the earth, the solar system condensed a lot of water in the form of ice, which existed in the rocks with continuous evolution and aggregation to form the earth, and finally through the action of the earth's internal temperature and pressure, the water penetrated out.
In addition, previous studies have shown that there may be abundant water resources in the Earth's interior, and the amount of storage is estimated to be about three times that of surface water.
Second: because the solar system appeared ice very early, they combined with rocks to form comets, when the comet hits the earth, the water will remain on the earth, and some people even think that comets not only bring organic matter and water, but also some primitive life.
There is nothing more than a combination of these two claims, but in the final analysis, it shows that this water came from the early solar system.
So that is to say, the water resources on the earth have been around for billions of years, and until now people, animals and plants are still drinking, and the body is still normal. So why does bottled water expire?
First of all, let's study the composition of water, water is nothing more than an inorganic compound composed of oxygen and hydrogen, their property structure is very stable, so from a chemical point of view, under normal circumstances, water is not easy to change qualitatively.
In addition, nature itself has a "self-purifying" function, and water bodies are no exception.
Most of the time, water exists on the surface as a liquid, forming lakes or rivers.
As the temperature rises, part of the water will enter the air in the form of water vapor, and as the temperature decreases, rain or snowflakes fall back to the ground, and the water is constantly flowing throughout the process.
In addition, the water of nature is basically living water, that is, water that can flow and circulate continuously.
It is precisely because of this openness that the oxygen content in the water is relatively high, and the microorganisms that rely on it can decompose the organic matter in the water, and will not give the organic matter the opportunity to rot.
Of course, there are other microorganisms that are doing their "work" conscientiously, and the natural water is in such a balanced state, forming a stable ecosystem, and nature will not deteriorate.
First of all, there is a big difference between bottled water and nature's water, that is, bottled water belongs to "backwater".
Although before assembly, workers will sterilize the microorganisms in the water once and will also do deoxygenation. But this does not mean that all microorganisms can be wiped out, and some anaerobic microorganisms are more suitable for reproduction.
Therefore, it is like a lake that cannot flow and circulate will eventually become a "stinky ditch", and bottled water cannot form a circulating flow, and naturally it will not be able to achieve the self-purification function of the water body.
Secondly, if you look closely, you will find that many bottles are generally written on the shelf life of the seal, and it is also recommended that you drink it within a day after opening the cap.
This is also because if the sealing of the bottle is not good, it also allows more microorganisms to enter, so that the water is naturally contaminated.
Finally, the reason why the water in bottled water is unstable is not all because of water, but because of the "plastic bottle" of clothes they wear.
Most bottles are made of polyethylene terephthalate, a polymer compound. Over time, its properties will be unstable, so that some low-molecular compounds are integrated into the water, and such water is naturally not recommended to drink.
Although the water source in nature does not deteriorate, this does not mean that humans can drink directly, and now people who pay attention to it will also install a water purifier in their homes, that is, because natural water is rich in microorganisms, or there are some substances that are harmful to the human body.
With the continuous progress of life, the human stomach will be more fragile, these unclean water sources will endanger the health of the human body, so the state will be through hierarchical screening when managing user water, and then the qualified water will be transported to each household.
In addition, for bottled water, it does bring us a lot of convenience, and in the short term, it can also ensure the safety of water quality, but in the serious pollution of today, we should personally reduce the pollution caused by plastics, reduce the frequency of use of bottled water.