For a long time, due to our country's economic backwardness, the low cultural level of the people, and the influence of old traditional concepts, there have always been toilets in the vast majority of urban suburbs, counties, towns, villages, and toilets without sewerage facilities. The facilities are simple, unhygienic, unsightly, and impractical, and have become a major source of disease transmission. With the deepening of urban and rural economic reform, the improvement of people's living standards and the rapid improvement of living conditions, the solution to the toilet problem should also follow suit. Therefore, doing a good job in the research and construction of toilets suitable for our country's national conditions is not only related to further reducing the The incidence of intestinal infectious diseases is an important measure to improve the health of 1.1 billion people and is also related to the change of customs among urban and rural people and the construction of two civilizations.
The "indoor dry toilet" developed by our institute was initiated in 1988 and installed and used in a farmer's house on the outskirts of Acheng City in 1989. In the past two years, the toilet has been completely installed indoors, does not need to be flushed with water, and has no odor. It has design requirements such as taste, pollution-free groundwater, cold protection and low cost. In 1990, it passed expert appraisal and was deemed to have reached the domestic advanced level. In 1991, it won the second prize of the Provincial Urban and Rural Construction Science and Technology Progress Award. And has applied for a patent.
II
In terms of research on waterless toilet flushing, some of the more technologically advanced countries in the world have already been ahead of us. They are either considered from the perspective of water conservation, or are used in villas without water or sewer pipes. Among them, there is a tilt-type compost box that combines kitchen and toilet treatment. It combines the decomposition of domestic waste and the decomposition of feces. It does not require any chemicals or any auxiliary equipment. It uses the aerobic principle to make the garbage self-decompose under the action of gravity. During the upward and downward movement, the volume is reduced by 90%, making garbage and feces harmless. There is also a kind of dry toilet, which has a base material that can decompose feces in the collection container, and uses a manual shaker to stir the feces and the base material to achieve the purpose of decomposition. In other dry toilets, after feces falls into the container, Urine and feces are decomposed separately through different ways, and some have built-in heating devices to ensure temperature, accelerate decomposition, etc. Regardless of the form, the most common thing about these toilets is that they do not require water to flush, are odorless, and have no environmental pollution after the feces is decomposed. This not only saves a lot of precious water, but also makes it possible to install indoor toilets in areas without water supply and drainage facilities. The Hokkaido area of ??Japan uses a large number of waterless indoor dry toilets. According to the Science and Technology News, Japan has specialized in the production of disposable plastic gaskets for toilets and automatic flushing, heating, drying, and dispersion toilets that can maintain a constant temperature in winter. Toilet supporting equipment with different functions such as scent, computer technology is also applied to toilets to analyze urine, measure people's body temperature, blood pressure and pulse, etc.
In terms of research on dry toilets, there is a big gap between us and developed countries. Of course, many aspects are economic. However, in recent years, due to the improvement of awareness and people's urgent demand to improve the environment, some provinces and cities have also developed or are researching dry toilets that are suitable for my country's national conditions and different regional conditions, despite insufficient funds and a late start. In the south, for example, in Yibin, Sichuan, there is a toilet with a biogas purification device that allows people to live on top of public toilets. The treated feces is not only harmless, but also built in conjunction with the biogas pool. The biogas generated by one public toilet is enough for the people living on top of the public toilet for a whole year. atmosphere, and transformed the environment. There are also waterless and odor-proof plastic dry toilets produced by a research institute of the Engineering Corps and the Acoustic Equipment Manufacturing Factory in Haidian District, Beijing, which fundamentally solve the problem of being odorless and flushing without water. In the Yellow River Basin, Song Lexin, a doctor at the Yucheng County Health and Epidemic Prevention Station in Henan Province, spent 10 years developing a "double-urn funnel-type" dry toilet. The toilet is located in an outdoor courtyard and is odorless and does not drain feces. However, they are located in the outdoor.
Three
The indoor dry toilet I developed is different from the luxurious ones abroad and also different from the style used in the Yellow River Basin in China. Instead, it is economical, practical, and cold and frostproof.
The dry toilet we developed is composed of four parts: a toilet (special equipment for dry toilets), a defecation pipe, a ventilation pipe and a toilet trough.
The toilet is made of ceramic and is a double-layered toilet. There are also single-layered toilets. When in use, open the top cover with your hands and block the opened toilet tightly with your body. Then open the second-layer partition by hand, and the excrement will first enter the fermentation solution with sufficient capacity through the smooth stool to be decomposed. When the excrement is large, it will flow into the storage room.
The toilet trough is constructed together with the new house. Its volume is calculated based on the excretion volume of the family population and is cleaned once a year. At the same time, there must be an air layer of about 40 centimeters high.
Considering anti-freeze, it should be buried about 1 meter below the freezing depth. Consider cleaning outdoors, so the toilet is buried under the foundation of the house and is divided into an indoor part and an outdoor part. Leave a cleaning opening in the outdoor part, and consider the two possibilities of manual cleaning and fecal suction truck collection. When not in use, pay attention to keeping warm. At the same time, consider using it as the air inlet of the toilet.
The biggest problems with indoor dry toilets are indoor odor issues and feces digestion.
1. No indoor odor problem
The deodorization of water flush toilets is to set up a trap under the toilet to prevent the odor in the pipe from spreading into the room. However, dry toilets The deodorization measure adopted is to set up a ventilation pipe on the toilet tank to extend out of the roof and expose it to the atmosphere. It is actually a chimney principle. The amount of fermentation is large and the amount of excrement is limited each time. It is very difficult for the excrement to enter the fermentation tank. It decomposes quickly, and the gas produced is quickly eliminated through the exhaust pipe.
Our actual measurements and calculations show that the toilets and ventilation systems we adopted are successful.
When the outdoor temperature is lower than the temperature inside the tank, the thermal pressure is positive and the air flows to the outside. On the contrary, when the outdoor temperature is higher than the temperature inside the tank, the ventilation of the toilet tank is not smooth, but because the feces in the tank is fermenting Gas is continuously generated during the process. When the gas in the tank accumulates to a certain amount, the pressure is greater than the outdoor pressure, and the gas is discharged into the atmosphere from the ventilation pipe. Natural ventilation is a complex process. When the temperature difference between the inside and outside of the tank is large, hot pressure exhaust is the main method. When the temperature difference is small, air pressure exhaust will make up for it. Moreover, hot pressure and negative pressure often act at the same time, and the two are inseparable. This ensures Natural ventilation effect. Not only that, the dry toilet is a sit-down toilet and has a double-layer sealed partition. The gas in the tank has no outlet indoors, which ensures that the odor does not spread into the room.
In addition, during use, it is also crucial to clean the toilet once or twice a week with a small amount of water (such as facial wash water).
2. Feces Digestion
Before use in dry toilets, about 5 kilograms of soybeans are fermented with about 100 kilograms of water. After fermentation, they are put into the toilet trough before use. When dry toilets are used, feces enter the toilet trough, and the feces in the tank is basically in an anaerobic state. Especially after the feces accumulates to a certain height, since no measures such as heating, blowing and stirring are taken, it will just ferment naturally under anaerobic conditions like the septic tank. After a year of use, we removed the feces from the toilet tank in early December. Samples were taken and analyzed for organic matter degradation and bacterial killing rate. The results are as follows:
Chemical oxygen demand (COD) degraded from 30,000 mg/L to 32,000 mg/L in fresh feces to 18,790 mg/L. , more than 40% is digested, and the biochemical oxygen demand (BOD) in 5 days is degraded from about 20,000 mg/L of fresh feces to 7,474 mg/L, which is about 50% digested.
The total number of bacteria dropped from about 1.1×1011 before digestion to 1.1×105 after digestion.
The number of E. coli bacteria increased from 9.0×109 before digestion to 9.0×106 after digestion (the moisture content of the digested sludge was about 80% during the test). It can be seen that the total number of bacteria and fecal E. coli were killed about 100 times.
From laboratory analysis, it can be seen that the natural digestion of feces under anaerobic conditions in the tank has satisfactory results. Its digestion effect is almost the same as that of sludge in large sewage treatment plants at medium temperature (33°C). , without any additional auxiliary facilities. Its digestive effect is basically similar to that of a flush toilet. Dry toilets do not use water to flush, which saves a lot of resources and energy. It has certain advanced nature. And there is no loss of manure.
Some digested manure is applied directly to farmland, but we recommend that it is best to use composting method to further mature before application. The reason is that the internal temperature of compost can reach about 70℃. In 40 days, almost all insect eggs and germs can be killed without requiring a lot of economic investment. Moreover, composting can also increase the fertilizer content.
Four
After years of practice, indoor dry toilets have good social, environmental and economic benefits. To sum up, the following points are as follows:
1. Improve the environment and reduce pollution
A considerable number of farmhouse toilets in the northern region are "pig and dog" toilets. First, after pigs eat human feces, the incidence of cysticercosis is increased. In our province It was once as high as 12-20%, causing considerable economic losses; secondly, flies breed in summer, increasing the incidence of human disease; thirdly, it pollutes groundwater. The penetration rate of tap water in rural areas of our province is about 30%, and a considerable number of farmers drink water that does not meet drinking water standards. shallow groundwater; fourth, the environment is not beautiful. Indoor dry toilets completely solve the above problems.
2. Utilize manure and turn waste into treasure
According to the data, the fertilizer content of an adult’s feces in one year is shown in the table below
The amount of fertilizer (catties) contained in the feces and urine excreted by an adult in one year
The amount of nitrogen excreted by category (N) is equivalent to ammonium sulfate phosphorus (P2O5), which is equivalent to potassium superphosphate (K2O) Equivalent to potassium sulfate
Human 180 1.00 9.00 0.90 4.5 0.67 1.40
Human urine 1400 7.00 35.0 1.82 9.1 2.67 5.55
***Total 1580 8.80 44.0 2.72 13.6 3.34 6.95
More than 900 million people in our country live in suburbs, counties, towns, and villages. In Heilongjiang Province alone, there are about 10 million adults living in such areas. If the feces is piped, Turning waste into treasure can be equivalent to 220,000 tons of ammonium sulfate, 30,000 tons of potassium sulfate, and 70,000 tons of superphosphate every year. What a huge economic figure this is.
3. Water-saving and energy-saving, the effect is remarkable
Under the current situation, the penetration rate of water supply in counties, towns and villages is not high, and drainage facilities are not available and there is no condition to build them. Indoor water flush toilets, but indoor dry toilets can be installed in all areas that do not have water flush toilets. Their functions can be compared with water flush toilets, and they save a lot of water. According to statistics, 40% of domestic water consumption standards About % are used for flushing toilets. Compared with two toilets with the same functions, dry toilets save a lot of water. There are 4 million rural households in our province. If 5% of them use dry toilets, there will be 200,000 households with the same water Compared with flushing toilets, if each household saves 50 liters of water per day, it will be 360,000 tons per year, which is equivalent to a medium-sized water purification plant. The effect is remarkable and the benefits are amazing.
4. Fully improve the living environment
If a residence is equipped with an indoor toilet, it will greatly improve the living conditions and increase the comfort of people's lives. In the north, there are no sewer facilities. In vast areas, especially in winter, where there is a large temperature difference between indoors and outdoors, indoor dry toilets are easy to use and reduce diseases, which is also an important part of the construction of two civilizations.
Fifth
As for the requirements for the construction of "sanitary toilets" in the vast rural areas by the end of this century, the National Patriotic Association clearly stated: "In accordance with the strategic deployment of the Party Central Committee on my country's economic development, with reference to The World Health Organization's global indicators, based on the current actual level, propose the minimum threshold for my country's rural areas to achieve the goal of "health care for all by the year 2000", that is, the penetration rate of sanitary toilets in four different economic areas in rural areas should reach 35% and 45% respectively. %, 70%, 80%. "We believe that the dry toilet developed by our institute will make due contribution to the realization of the above goals.