When it comes to drains, the first impression is definitely turbid water, accompanied by stench. Most drainage ditches are dirty, whether in urban or rural areas. But in Japan, they can still raise fish in the drainage ditch, which is still a "koi fish" that pays great attention to the growing environment. What happened?
Japan is famous for its "cleanliness", which is inseparable from the Japanese's emphasis on environmental protection. But raising "koi fish" in the sewer is more or less incredible. A famous donkey friend saw this scene in rural Japan before. In the drains of country roads, the water quality looks very clear, and many koi fish swim freely like a water tank, which is of great appreciation value.
The donkey friends are very puzzled about this. Why are the sewers in Japan so clean? And why do you want to raise an animal like koi fish, which is difficult to raise? Are you showing off something? So he asked the local people, and the local people told him that it all started a long time ago. Although the sewers in Japan are very clean now, in fact, Japan once faced the problem of water pollution. After World War II, Japan neglected environmental protection in pursuit of economic development. Although Japan's economy grew rapidly in the 1960s, the phenomenon of environmental pollution was particularly serious. During that time, the Japanese not only suffered from environmental pollution, but also had a very bad reputation in the world.
In the worsening situation, environmental problems in Japan finally broke out. Many people get sick from drinking polluted water sources, and even lose their lives in serious cases. This incident made the Japanese aware of the urgency of protecting the environment, and Japan also began to issue various legal documents to appeal to local people to care for and protect the environment. Since then, the whole country has attached great importance to the cultivation of environmental awareness, and some people have organized environmental protection activities together. It is said that people in Setogawa first put more than 2,000 koi fish into the drainage ditch to urge all people in this area to protect the environment and not to dump domestic sewage indiscriminately. With the persistence of these people, many regions have followed suit, and there are more and more cases of raising koi fish in the drainage ditch.
The water in the drainage ditch is not domestic sewage and industrial wastewater, which naturally ensures the clarity of the water source in the drainage ditch. Hearing this, the donkey friend immediately asked the local people, "If the Japanese don't pour domestic sewage into the drainage ditch, how do they discharge their domestic sewage?" ? In fact, the drainage system in Japan is very advanced, which is different from the sewage system. The Japanese will separate rainwater from sewage and carry out strict water classification. Only the drainage system is divided into three layers.
The first floor is surface water discharge, and the drainage ditch belongs to the first floor, which is equivalent to the role of diversion canal. Basically, the surface water is collected, especially rainwater, which is relatively clean. The second floor is domestic sewage. Japan centrally treats domestic sewage. They have special domestic sewage treatment plants, which ferment and decompose domestic sewage, refine it into high-concentration fertilizer and provide it to farmers. Then, the purified domestic sewage is recycled to supply industrial water. The last layer is industrial water, which is located at the bottom of the drain.
But in Japan, not all drainage ditches can raise fish, and most of them are located in rural areas or suburbs on the edge of cities. Bian Xiao thinks that the Japanese can raise fish in the gutter. In addition to their high awareness of environmental protection, it is very important that they have done a good job of sewage diversion, which has largely avoided water pollution. I wonder what you think of this phenomenon? Welcome to leave your original opinion in the comment area!