饮用水与健康（Drinking water and health）
The concept of a conflict, drinking water
Undoubtedly, with the increasingly severe environmental pollution, water has become an important factor threatening people's health. According to the WHO statistics, 80% people drinking water and the incidence of unclean. In recent years, the market of various brands of mineral water, pure water and water purifiers increasing, drinking water what is beneficial for the body, it is very concerned about the event.
On the one hand, people on the quality of tap water sceptical, even afraid of production process make the water tap water mixed with some toxic gases, that pure water and mineral water is more beneficial to health. On the one hand, experts believe that the current market on pure water and mineral water is not necessary for high consumption products, even pure water is harmful to the human body, urged the public to drink their own water.
So, in the end we should have what kind of drinking water? Mineral water is necessary in daily life? The water is not pure enough? Tap water is really harmful to human body?
Two, pure water and mineral water and human health
The biggest difference between mineral water and pure water, the water is different. The real mineral water taken from deep underground confined water, the water needed for the human body contains minerals and trace elements. The purified water is to use city tap water or water from wells, through the reverse osmosis membrane purification treatment, so that the water
becomes very pure, does not contain any bacteria and other substances other than water.
What mineral water is good, without any other material or water?
I group according to the collected data found in the following conflict perspective.
Experts advocate drinking mineral water that a person drink every day more than 2 kg of water, water is the best solvent, rich in mineral water by various wholesome ingredients should make full use of. Although the purified water to remove all harmful substances, but also removes water useful things. Especially the pure water solution with strong ability, in a large number of people drinking water, nutrients and trace elements in the human body will quickly dissolve in the water, and then excreted through the kidneys in vain, so, don't drink too much pure water. Especially often drink pure water, the greater the impact on children. At present, many city has issued a notice prohibiting the students drink pure water, to ensure that the trace elements and nutrients in these growing children a
re not being lost.
Experts advocate drinking pure water is that water is mainly thirst, and pure water is the best drink. Pure water has a very strong dissolution and penetration ability, in the supplementary water at the same time, to remove the body of toxins and impurities can make some excretion of harmful substances stored in the body.
They believe that the nutrients and trace elements needed by the body does not have to depend on the water can get from food.
The content of trace elements in food is much higher than that of water, such as a cup of orange juice in the mineral content of more than 400 cups of mineral water; 1 grams of black fungus is equal to 10 cups of mineral water containing iron value. The trace elements in mineral water is not worth mentioning, harmful substances dissolved in water can make people sick.
Two party experts say is reasonable, however, with the background of serious environmental pollution has many deep groundwater dissolved into the harmful substances, such as bad water, mineral water "congenitally deficient", it is difficult to achieve the standard of drinking. Then we learned about "hard knowledge, we know that the water contains minerals is not the more the better.
Long term drinking water hardness is too high or too low is not conducive to human health. Although the purified water is very pure, but many nutritionists believe that pure water once unsealed or seals in contact with the air within 24 hours will be breeding bacteria. Moreover, excessive drinking water will lead to the loss of trace elements in the human body needs, not to mention the current quality on the market most of the drinking water problems.
Three, tap water really harmful to human health?
Now people talk about drinking tap water will haunt, mainly because of fear of not removing impurities and microorganisms as water tap water production process, and afraid of the water purification process with some toxic gases. Based on this,
My group members first begin to understand the production process of tap water.
1, tap water is how to produce?
As everyone knows, because of natural and human factors, contains a variety of impurities in raw water. From the angle of water treatment, these impurities can be divided into colloidal suspensions, and dissolved in three categories. City water plant water treatment is to remove the raw water to hum
an health and industrial production of suspended matter and harm of colloids, bacteria and other harmful ingredients, so that the quality of the purified water can meet the need of drinking water and industrial production. City Tap Water Corporation water by conventional water treatment process, it includes mixing, reaction, sedimentation, filtration and disinfection processes.
(1) the coagulation reaction process
Raw water of the water pump after the upgrade, the first after the coagulation process, i.e.:
The raw water + water treatment agent, mixing, reaction, water.
Since the agent evenly mixed with water until the large particle floc formation, general coagulation process. The commonly used water treatment agent with poly aluminum chloride, aluminum sulfate, ferric chloride. Shantou city is the use of basic aluminium chloride. According to the chemical properties of aluminum, aluminum ion in water into chemical ionization of water molecules, and it has the following reversible reaction:
Al3+ + 3H2O vs. Al (OH) 3 + 3H+
Aluminum hydroxide has adsorption effect, the water is not easy to precipitate particles and small su
spension destabilization and mutual coalescence by bridging to form larger flocs, separated from the water, in order to settle down.water pollution
The mixing process requirements quickly after adding the medicine. Mixed purpose is through intense mixing, hydraulic machinery, so that agents rapidly and uniformly dispersed in water.
The coagulation treated water through the pipe into the sedimentation tank, clean water into second stages.
(2) precipitation treatment
Mixed floccule coagulation stage formed by means of gravity separated from the water by a process known as precipitation, this process in the sedimentation tank. Water flows into the settling zone, distribution of the area of the cross section into the settling zone, and then slowly to the outlet area. The water particles sink to the bottom of the pool, sludge piled up and concentrated, regularly drained away.
(3) filtering
Filtering generally refers to the granular quartz sand filter layer in the gap by suspended particles thr
ough adhesion, thus further removal of fine suspended impurities, organic matter, bacteria, virus, so that the water clarification process.