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Normally, the solid excretion of each person is about 200 grams, and the urine is about 1500 ml. In this way, the whole Chinese excrement reached 2.4 million tons. Where did such a huge excrement go? How did they deal with it?
The treatment of human excretion in human history
When it comes to the Middle Ages, people often think of dark church rule, constantly rolling epidemic diseases, etc. Of course, they are also indispensable for the dirty European urban streets. The emerging prosperity of cities has brought not only an increase in commodity trade, but also a surge in population.
In the harsh environment, and the urban sewage system was not built at the time, the public discarded casual garbage and feces in the streets and alleys. Therefore, at that time, there was a stench on the streets of Europe, and flies and ants flew.
Corresponding to the East, the development of traditional Chinese medicine allows the public to realize early that the human body excrement needs to be properly treated, otherwise it may cause epidemic disease. Therefore, a special type of profession was born, and later dung workers belonged to this category.
Although they are always disgusting, they have to say that their existence does solve the problem of urban health and environmental problems. In addition, China was mainly agricultural at that time, and the population agglomeration was less than Europe, so the urban environmental hygiene was relatively good.
Time has come to the founding of New China. The Chinese people who have experienced a century -old war can finally start to start production and construction, the modernization process has gradually accelerated, and the urban population has ushered in a climax of growth.
The increase in population means that excreta also increases, and how to deal with it has become a problem for many urban families. Taken together, my country’s feces treatment system can be divided into four stages:
In the 1950s, the New China was just established at this time, and the production and construction of various places were regaining in an orderly manner. The urbanization process was not fast. Therefore, most of the households continued the previous processing methods and dumped it reasonably on the street and nearby. But over time, this is not conducive to environmental sanitation.
In order to rectify the problem of dumping excretion at that time, the state has set up a dung station, and it is enabled to pour the excrement to the designated place in order to facilitate the concentrated processing of excrement in the social public system. Regarding some of the stations that have not been established, the state has also appointed specialized manpower or animal vehicles to collect uniformly. The collected excrement is often composed of compost treatment, which is used for the use of agricultural fertilizers.
We call this period the construction period of feces collection facilities.
With the development of machinery and the improvement of people’s living standards, flushing toilets have begun to appear, and some families have begun to be equipped with independent toilets, and cities and rural areas have also begun to build large and small public toilets. The excrement has been collected at this stage, and the amount has gradually increased. Of course, it is impossible to rely on manpower or animal power to complete the transshipment of excrement. At this time, the vacuum -absorbing vehicle came into being and promoted vigorously.
With the addition of machinery, a large number of dung workers have also died. After the reform and opening up in 1979, the number of manure suction vehicles exceeded thousands, accounting for about 20 % of the sanitation vehicles.
We call this stage as a period of mechanization of feces clearance.
The use of manure suction vehicles has continuously accelerated the speed of urban treatment of excrement. Simply collecting and composting for agricultural use can not meet people’s demand for hygiene and health. More advanced feces treatment technology is also born, that is, feces are harmless.
In the 1980s, my country introduced advanced foreign excretion treatment equipment and began to build a septic and water treatment plant. This stage can also be called the stage of feces harmless treatment.
The increase in population, especially in recent years, has accelerated, and a large number of population has begun to pour into cities. In order to cope with the needs of residents’ daily lives, urban construction is gradually being improved, and sewage treatment pipelines have also entered every household.
At this time, the feces treatment system was included in the urban sewage treatment system, and a lot of life wastewater such as excrement was transported to the septic tank in the area.
Here, excreta, etc., will be simply degraded, and finally transported to the urban sewage treatment plant. In the mid -1990s, the merger of sewage and garbage treatment plant was jointly responsible for the treatment of urban residents excrement. During this period, we are also known as the construction period of urban feces treatment system.
From the continuous new ways of the treatment of residents’ feces and excretion, we can see that the pace of modernization of my country’s modernization is constantly accelerating, and the living standards of residents are gradually increasing. In fact, after the founding of the People’s Republic of China, the population of our country has gone through a period of great explosion, and the pace of urbanization has gradually accelerated.
Without handling these human excuses, it will be a terrible disaster. As part of the urban public basic cause, it has not only the health of the people, but also the embodiment of the national comprehensive strength. So, what kind of process will the excrement of these human body have been formed?
Where did the feces go?
In the urban feces treatment system, it can be regarded as a wastewater. Here is a popular science. In the urban sewage treatment system, sewage is divided into two types: black water and ash. Among them, black water is usually the human body excrement, mainly sewage produced by the toilet; other daily water, such as washing, laundry, bathing, etc., we call gray water. But in any case, the two eventually had only one destination and transported to the sewage treatment plant together.
Well, please recall, when you end up, after pressing the flushing keys, the water flows the excrement that you generate into the water pipe. Then mixed with the excretion of the water into the septic tank embedded next to the building.
In the septic tank, the sewage pipe is connected at one end, and the other link is the urban sewage pipe. Under normal circumstances, the septic tank consists of three parts, including first -level/secondary anaerobic chamber and a clarification room.
The functions played by the first and secondary anaerobic chambers are probably the same. The sewage here has gone through the precipitation, and then the principle of anaerobic bacteria fermented was used to hydrate two rounds of hydrolysis, and finally the two parts of the dung and the manure were formed.
Affected by gravity, the dung slag will be reduced to the bottom layer, and the feces are on the upper layer. After fermentation and treatment, a large amount of bacteria and parasites have been eliminated at this time. After entering the clarification room for the final static treatment, the manure will enter the sewage treatment plant with urban sewage pipes.
Of course, it is impossible to disappear for no reason, and it is impossible to let it go. Human stool actually contains a lot of energy, and many bacteria are obtained by decomposing feces to get their own energy.
During the decomposition process, methane gas is generated, that is, the biogas we often call. Everyone knows that biogas is a kind of abundant gas. When the internal gas pressure reaches a certain degree, the risk of explosion risks suddenly. At this time, manpower is needed to solve it.
The actual dung worker in 21 is no longer carrying baskets, holding tools, and humming. With the development of mechanization, major cities are equipped with feces.
When the septic tank is found to a certain degree, drove the septic vehicle near the septic tank. After a simple operation, the sediment at the bottom can be sucked out. The whole process is efficient and convenient, and it is dirty and dirty.
These sediments are not useless. Most of them will be further dehydrated, and then the landfills or compost to see the arrangement of different time nodes in various places. In our country, the septic tank clearance work has also made clear requirements. In the shortest quarter, the longest cannot exceed one year.
Sewage treatment plant
As mentioned earlier, the feces treatment system will eventually be gathered in the urban sewage treatment system, and the terminal of the urban sewage treatment system, the sewage treatment plant is the most critical stop to solve the feces problem.
Generally speaking, urban sewage mainly contains two major contents, one is organic pollutants, and the other is nitrogen phosphorus pollutants. Therefore, the sewage treatment plant is also processed according to these two substances.
In the first stage, the first thing to be removed is solid pollutants. For example, gravel and slag, etc., will be sieved at this stage. After completing the simple filtration of the first stage, it began to enter the second stage to decompose organic matter. At this stage, more than 90 % of soluble organic pollutants will be removed.
Entering the third stage, further filtering the residue, and also need to remove inorganic pollutants such as disinfection water, nitrogen and phosphorus, and final treatment of organic pollutants.
After experiencing the water quality after these three stages, it can basically meet the national emission standards, enter the rivers, lakes and sea, and then rely on the self -purification ability of the earth’s water circulation to become raw water.
The water plants of major cities can be extracted, and then they can be purified and can become normal residents. Considering the convenience of sewage treatment and emissions, the sewage treatment plants in most cities are built in the downstream of the city and low -lying areas.
Of course, we can find that the sewage treatment plant will also be sieved by some residues or solids, and they cannot dissolve in water and forced to precipitate. Most of them are some heavy metals or chemical salts. They have accumulated in one place for a long time, which is also not conducive to environmental health. Therefore, like the septic tank, they also need to deal with it regularly to prevent pollution from the surrounding air.
In summary, there is a water cycle in nature, and people in urban life also experience water circulation. The feces, urine, etc. we excreted, have gradually become harmless or low -harmful ordinary water through complex and orderly urban sewage treatment systems. After being treated with natural water plants, we will re -enter our daily life.
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