How to balance the production of 1 liter of purified water and the waste of 3 or 4 liters of tap water in China？
According to Voice of China’s Global Chinese Broadcasting Network, I believe that in many cities in China, people may be familiar with such a scene: in residential areas, people take blue buckets to swipe their cards in front of a cabinet water purifier to receive water, or in their own kitchens, they get drinking water through filtering equipment.
With the improvement of people’s requirements for drinking water quality, people pay more and more attention to the safety and health of drinking water, and water purifiers have become the "new favorites" of many families and communities. However, there is also a contradiction between water purification and water saving.
Mr. Wang, a citizen of Qingdao, bought a household water purifier at the beginning of this year. He can drink pure water by turning on the tap, which makes the family’s life much more convenient. But at the end of the month, when I saw the water meter, Mr. Wang was startled.
Mr. Wang: The water fee at home is 20 to 30 yuan. Since this was installed, I think it was basically between 40 and 50 in the first two months, which was basically doubled. Later, I learned after asking that after it produced one cup of water, it would basically produce three to four more cups of wastewater.
The water purifier has become a waste water machine, so invisible water waste exists not only in household water purifiers, but also in water purification drinking machines set up in many communities. The reporter learned that in many communities in Qingdao, there are three or four such direct drinking machines for water purification. If you put in a piece of 30 cents, you can receive a small bucket of 7.5 liters of water. Because it is more affordable than buying bottled water, many citizens like this direct drinking machine very much. But in the interview, most citizens said they didn’t know about the water waste caused by the direct drinking machine.
Citizen: (I used to think) it is so economical and not wasteful, but I didn’t know it was so wasteful.
How much water is wasted by this drinking machine? The staff of the water company calculated an account for the reporter. To put it simply, it takes three buckets of tap water to make such a bucket of pure water. The reporter learned that the lowest wastewater rate of water purifiers is 1: 1, and the highest can reach 1: 4. According to the data released by home appliance research institute Yikang, in 2014, there were about 15 million reverse osmosis water purifiers in use in China, and the average annual water consumption of each household reverse osmosis water purifier was about 30 tons, and that of commercial ones was about 60 tons. Only by measuring the low average wastewater rate of 1: 1: 23, there were about one billion tons of tap water lost in vain every year. Insiders reminded that while enjoying clean water, don’t forget to save water.
If you use the reverse osmosis water purifier to produce 1 liter of pure water, 3 to 4 liters of water will flow into the sewer. Many times, these "tail waters" which are cleaner than tap water are wasted. However, in the reality that the situation of water resources in many areas of our country is extremely severe, it seems that water purification and water saving are becoming a pair of contradictions. So is this contradiction simply due to poor water use and insufficient water purification technology? How to achieve a good combination of water saving and water purification? We might as well take a look at some water consumption conditions in overseas countries.
As the largest island country in the world, Australia can be called "vast territory and abundant resources". However, due to the dry climate and large evaporation, Australia is a country with relatively short water resources. Hu Fang, an Australian observer of Global Chinese Broadcasting Network, told us that tap water in Australia directly meets the drinking water standard. Therefore, most people drink tap water directly, and do not need secondary purification. Because the water plant directly carries out the water purification treatment, it will save some water compared with the water purification for each camp.
Hu Fang: The cold water outlet of tap water in Australia has reached the standard of direct drinking water, so few people install a water purifier at home. Usually, people drink water directly from the tap with cups. For some places with high hygiene requirements, such as hospitals or kindergartens, patients or children are directly allowed to drink tap water. Because it is the direct water purification treatment of the waterworks, in the process of water purification, the waste water is not directly dumped, but repeatedly recycled in the waterworks. Therefore, compared with the fragmented water purifier for each household, it will consume less water resources to filter water again.
In addition, Australia’s water resources management is also quite detailed. For example, tap water can be divided into cold water and hot water. Cold water can be drunk directly, and hot water can be used as domestic water, such as bathing and washing vegetables. It is not as pure as cold water and cannot be drunk directly. Treating cold water and hot water differently can make less water need to be purified, which is also a way of saving water.
Hu Fang: On the other hand, there will be two outlets of cold water and hot water at the faucet outlet in Australia. Cold water can be directly drunk, while hot water can be used as domestic water, such as bathing and washing vegetables, so the requirements for hot water will not be as pure as cold water. Treat hot water and cold water separately, so that less water needs to be purified, and relatively less water resources are consumed in the process of water purification. In addition, Australia itself is a country that lacks water. In many details, Australians will pay great attention to saving water. For example, in some airports or shopping malls in Australia, the water used for flushing toilets is not tap water that can be directly drunk. Usually, these places will use recycled water for flushing toilets. In addition, many buildings in Australia have a water storage tank in which rainwater after rain will be collected. Usually, the water will be used for flushing the toilet and cleaning the floor, thus further reducing the amount of direct drinking water that needs purification treatment.
Tang Xinzi, a Japanese observer of Global Chinese Broadcasting Network, told us that Japanese people’s drinking water also comes directly from tap water. Mineral water and purified water are often emergency items for Japanese people to prepare for disasters. At the same time, Japan’s water resources treatment system is quite transparent to the public.
Tang Xinzi: When I returned to China, I found that, including my own home, pure water was delivered to my door in buckets. This phenomenon has never been seen in Japan. Turning on the tap in Japan is basically drinkable water, which is the same in urban and rural areas. There are 35 strict requirements for the standard test of water system management. Children are taken to visit local water purification facilities from the beginning of primary school to learn how to clean drinking water in the community. The whole water purification process is transparent for users to see. Japan first carries out disinfection treatment, then carries out a higher level of water purification treatment to remove impurities, and finally sends it to the tap of every family, and you can drink it when you turn on the tap.
In the United States, sometimes the problem of tap water pollution also appears in social news. Water purifiers, net kettle and mineral water are one of the water sources for many families. What is the real situation of American daily drinking water? Xing Sijia, the international news editor of Voice of China, once studied in the United States. She introduced this.
Xing Sijia: I once asked Americans in new york and Washington, D.C., whether tap water at home can be directly used for drinking. Most of them said that they believed that drinking tap water directly had no health problems. However, the reality is that most American families will install a water filter under the faucet in the kitchen to further improve the quality of drinking water. In fact, as early as 1974, the United States Congress passed the National Safe Drinking Water Act, which ensured the safety of drinking water through the protection of the whole process from the water source to the faucet. There are currently more than 160,000 public water supply systems in the United States, including public and private companies. According to the report of the US Environmental Protection Agency, according to the different water sources, American water companies can choose appropriate process combinations to deal with pollutants found in raw water. The most common water purification process includes flocculation, precipitation, filtration and disinfection. Some water supply systems also use ion exchange and absorption methods. It is understood that these methods have not caused excessive waste of water resources. In addition, in order to ensure the timely and accurate test results of tap water, the EPA has also established a set of sampling procedures for the water quality of tap water companies. For example, bacteria should be checked once a month or once a quarter according to the size of the water plant. However, even so, tap water in the United States has been exposed to potential safety hazards from time to time. As early as the end of 2009, the new york Times reported that tens of millions of Americans had problems with their drinking water, and 49 million Americans had been drinking dirty water for at least five years, which not only contained bacteria,It also contains dangerous chemicals such as arsenic and uranium. The reason, according to expert analysis, is that the infrastructure of the water supply system in the United States is in disrepair and aging seriously.