The Village continues to tell how the things that the townspeople use every day work. In this issue - the sewerage system. After we press the flush button on the toilet, turn off the faucet and go about our business, tap water turns into sewage and begins its journey. To get back into the Moscow River, she needs to go through kilometers of sewer networks and several stages of cleaning. How this happens, The Village found out by visiting the city's wastewater treatment plants.
Through the pipes
At the very beginning, water enters internal pipes houses with a diameter of only 50-100 millimeters. Then it goes along the network a little wider - courtyards, and from there - to street ones. At the border of each yard network and at the point of its transition to the street, a manhole is installed, through which you can monitor the operation of the network and clean it if necessary.
The length of city sewer pipes in Moscow is more than 8 thousand kilometers. The entire territory through which the pipes pass is divided into parts - pools. The section of the network that collects wastewater from the pool is called a collector. Its diameter reaches three meters, which is twice as large as the pipe in the water park.
Basically, due to the depth and natural topography of the territory, the water flows through the pipes itself, but in some places it is required pumping stations, there are 156 of them in Moscow.
Wastewater enters one of the four treatment facilities. The cleaning process is continuous, and the peaks of the hydraulic load occur at 12 noon and 12 noon. Kuryanovskie treatment facilities, which are located near Maryin and are considered one of the largest in Europe, receive water from the southern, southeastern and southwestern parts of the city. Effluent from the northern and eastern parts of the city is fed to treatment plants in Lyubertsy.
Treatment
Kuryanovsk treatment facilities are designed for 3 million cubic meters of wastewater per day, but only one and a half comes here. 1.5 million cubic meters is 600 Olympic pools.
Previously, this place was called the aeration station, it was launched in December 1950. Now the treatment plant is 66 years old, and Vadim Gelievich Isakov worked here for 36 of them. He came here as a foreman of one of the workshops and became the head of the technological department. When asked if he expected to spend his whole life in such a place, Vadim Gelievich replies that he no longer remembers, it was so long ago.
Isakov says that the station consists of three cleaning units. In addition, there is a whole complex of facilities for the treatment of sediments that are formed in the process.
mechanical cleaning
Muddy and foul-smelling sewage comes to the treatment plant warm. Even in the coldest time of the year, its temperature does not fall below plus 18 degrees. Waste water is met by a receiving and distributing chamber. But what happens there, we will not see: the cell was completely closed so that the smell did not spread. By the way, the smell on the huge (almost 160 hectares) territory of the treatment plant is quite tolerable.
After that, the stage of mechanical cleaning begins. Here, on special gratings, garbage that floated along with the water is retained. Most often, these are rags, paper, personal hygiene products (napkins, diapers), as well as food waste - for example, potato peelings and chicken bones. “What you will not meet. It used to be that bones and skins from meat processing plants sailed, ”they say with a shudder in the sewage treatment plants. Of the pleasant - only gold jewelry, although we did not find eyewitnesses of such a catch. Seeing the trash-retaining grate is the most terrible part of the tour. In addition to all the nastiness, many, many circles of lemons were stuck in it: “You can guess the time of the year by the contents,” the employees say.
A lot of sand comes with wastewater, and so that it does not settle on structures and clog pipelines, it is removed in sand traps. Sand in liquid form enters a special area, where it is washed with technical water and becomes ordinary, that is, suitable for landscaping. Wastewater treatment plants use sand for their own needs.
The stage of mechanical cleaning in the primary settling tanks is being completed. These are large tanks in which fine suspension is removed from the water. Here the water comes in cloudy, and leaves clarified.
Biological treatment
Biological treatment begins. It takes place in structures called aerotanks. They artificially support the vital activity of a community of microorganisms, which are called activated sludge. Organic pollution in water is the most desirable food for microorganisms. Air is supplied to the aeration tanks, which does not allow the sludge to settle, so that it comes into contact with the wastewater as much as possible. This goes on for eight or ten hours. “Similar processes take place in any natural reservoir. The concentration of microorganisms there is hundreds of times lower than what we create. Under natural conditions, this would last for weeks and months,” Isakov says.
The aerotank is a rectangular tank divided into sections, in which waste water snakes. “If you look through a microscope, then everything is crawling, moving, moving, swimming. We make them work for our benefit,” our guide says.
At the outlet of the aeration tanks, a mixture of purified water and activated sludge is obtained, which now need to be separated from each other. This problem is solved in secondary settling tanks. There, the sludge settles on the bottom, is collected by sludge pumps, after which 90% is returned to the aeration tanks for a continuous cleaning process, and 10% is considered excess and is disposed of.
Return to the river
Biologically purified water undergoes tertiary treatment. To check it, it is filtered through a very fine sieve, and then it is dumped into the outlet channel of the station, on which there is an ultraviolet disinfection unit. Ultraviolet disinfection is the fourth and final stage of cleaning. At the station, the water is divided into 17 channels, each of which is illuminated by a lamp: the water in this place acquires an acidic hue. This is a modern and the largest such block in the world. Although according to the old project it was not, earlier they wanted to disinfect the water with liquid chlorine. “It’s good that it didn’t come to that. We would have killed all living things in the Moscow River. The reservoir would be sterile, but dead,” says Vadim Gelievich.
Simultaneously with water treatment, sludge is dealt with at the station. Sludge from the primary clarifiers and excess activated sludge are treated together. They enter the digesters, where, at a temperature of plus 50-55 degrees, the process of fermentation goes on for almost a week. As a result, the sediment loses its ability to rot and does not emit an unpleasant odor. This sludge is then pumped to dewatering facilities outside the Moscow Ring Road. “30–40 years ago, the sediment was dried on silt beds under natural conditions. This process lasted from three to five years, but now the dehydration is instantaneous. The sediment itself is valuable. mineral fertilizer, in Soviet times it was popular, state farms took it with pleasure. But now no one needs it, and the station pays up to 30% of the total cleaning costs for disposal, ”says Vadim Gelievich.
A third of the sludge breaks down, turning into water and biogas, which saves on disposal. Part of the biogas is burned in a boiler house, and part is sent to a combined heat and power plant. A thermal power plant is not an ordinary element of treatment facilities, but rather a useful addition that gives treatment plants relative energy independence.
Fish in the sewer
Previously, there was an engineering center with its own production base on the territory of the Kuryanovsky wastewater treatment plant. Employees set up unusual experiments, for example, they bred sterlet and carp. Some of the fish lived in tap water, and some in the sewer, which was cleaned. Now, fish is found only in the discharge channel, there are even signs “Fishing is prohibited” hanging there.
After all the purification processes, the water goes through the discharge channel - a small river 650 meters long - into the Moscow River. Here and everywhere, where the process takes place in the open air, many seagulls swim on the water. “They do not interfere with the processes, but spoil the aesthetic appearance”, Isakov is sure.
The quality of treated wastewater discharged into the river is much better than water in the river according to all sanitary indicators. But drinking such water without boiling is not recommended.
The volume of treated waste water is equal to approximately one third of all water in the Moscow River above the discharge. If the sewage treatment plants were to fail, the settlements downstream would be on the verge of an ecological catastrophe. But this is practically impossible.
It is not enough to bring water into the house, after use it needs to be put somewhere. It’s hard to take out buckets, and it’s somehow pointless: water comes into the house by itself, and then it is taken out on foot. At least elementary sewerage is needed for a house or a summer residence. The option to simply remove the pipe from the house and drain the water to the ground or a small hole will not suit everyone. It doesn't look very good, and an unpleasant smell from this puddle or pit is almost guaranteed. What to do?
So, we will need: an old metal or plastic barrel, a certain amount of sewer pipes (at least 6 meters, preferably PVC 110mm), a tee, a branch, about 0.5 cubic meters of medium fraction crushed stone, a shovel and a few hours of our precious time.
We choose a place for our drainage well. Preferably, no closer than 5 meters from the house, no closer than 20-25 meters from a well or well and downstream of them downstream of groundwater. We dig a hole with a diameter greater than the diameter of the barrel by at least 0.5 m (diameter of a standard barrel is 0.6 m, height 0.9 m, volume 0.2 cubic meters) and a depth of about 1.5 m (preferably deeper). We make holes in the walls of the barrel, if metal, then with a grinder, if plastic, then with a hacksaw for wood with a small tooth. We make a hole for the incoming sewer pipe in the wall, not far from the bottom of the barrel. We fill at least 20 cm of gravel at the bottom of the pit and put the barrel upside down, orienting the hole under the pipe towards the house.
Now you need to dig a trench under the sewer pipe, leading it to the place you need. The pipe must be laid with a slope of at least 3 mm per meter towards the barrel. It can be brought into the house either under the foundation, or through a hole in it. There is no need to insulate the pipe, the water flowing through it will warm it perfectly. Not far from the barrel, we put a tee with a small piece of pipe coming out above the ground to circulate air inside the barrel and let air out of the sewer when it is filled from the house (so that the air from the barrel does not go into your house). We lead the pipe into the barrel through the hole made for this. We fill the gap between the barrel and the wall of the pit with gravel to the entire height of the barrel. At the bottom of the barrel, it is advisable to put some non-rotting material (a piece of old slate is perfect). We fill both the trench and the pit with soil, carefully tamping it down. We make a hole in the floor or wall of the house, finally leading the sewer into the house. Further at your discretion. On a piece of pipe sticking out of the ground near a buried barrel, you can put on a plastic fungus, which is difficult, but can be found in stores.
And now the nuances.
This is an exclusively drainage sewer for the house, it will not cope with fecal effluents, it cannot be cleaned or serviced in any way, and it is not intended for this. This sewer can be used for drains from the kitchen or from the bath. The same device has drainage wells from a septic tank.
The microclimate for bacteria that process wastewater depends on the depth of the pit. Ideally, the depth of the pit should be: the depth of soil freezing + the height of the barrel + the height of the crushed stone cushion (for the Leningrad region: 1.2m + 0.9m + 0.2m = 2.3m). But digging so deep is hard and not necessary. Drains also heat the barrel.
If the soil at the installation site of the sewer is clayey, and the water from the barrel leaves slowly, then the sewer for the house can be slightly improved. To do this, you need to lay another sewer, and preferably a drainage pipe. This pipe may lead water to a drainage ditch at the boundary of the site, or it may not lead anywhere, ending in a dead end. The task of this pipe is to remove excess water from the barrel, thus increasing the area of water absorption into the soil (irrigation area). The pipe is laid in a trench on a crushed stone pillow and is also covered with crushed stone, and then with soil. The depth of the trench is greater than that of the supply pipe, and the slope is directed away from the barrel. Naturally, the sewer pipe will have to be spoiled with a certain number of holes in the lower part to improve the flow of water, making it look like a drainage pipe. This is not required if the pipe is led into a drainage ditch.
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- To be honest, I'm a little surprised that someone's sewer can freeze. Sewer pipes, in principle, cannot freeze, there ...
Reviews (38) on "The simplest drainage sewage system for a summer residence."
Depends on the distance and features of the problem being solved. It is better to make the 110th PVC, it is more reliable, although more expensive. At distances up to 5 (five) meters, you can make the 50th (fifty dollars), but, preferably, also PVC (not always available in stores) - as more durable and frost-resistant. This is still an external sewage system, not an internal one.
Answers Vladimir.
1. And not only that, Vladimir, especially in loam, even on the surface. For example, it can be bent by swelling of the soil so that the slope in some area is broken. The consequences are the same, it will clog in general ... If it doesn’t break.
This also happens with a 110-pipe, but much less often, of course, subject to the elementary laying rules.
2. For "internal wiring" it will definitely not work. We need PVC for outdoor sewage. For internal sewerage usually use PP. You won't dig it up for the winter...
A “black pipe” is usually a HDPE pipe, not a PVD pipe (I haven’t heard anything about PVD pipes until now, maybe I don’t have enough experience). In principle, you can do it, if you find it, only there may be problems with joining pipes with bends (turns) and leaving the house. If you are not a "specialist", then it is better not to experiment.
4. Rain runoff is usually directed to the drainage system around the house, and it brings them to the drainage ditch. Other pipes are used there - "drainage", corrugated plastic pipes with perforation and protection with geotextile.
In loamy soil for house drains, it is imperative to make at least a small irrigation field (small drainage system just for that). Because loamy soils do not absorb water well. On the other hand, if you are “on arrivals”, then the usual crushed stone dressing around the barrel (simplified drainage system) should be enough for a long time.Of course, you can bring rainwater into this sewer system, but ... Then there will be a high probability of damage to the pipes by autumn and spring waters during “zero crossings”, because you do not control the volume and composition (maybe already with ice) of these waters. Therefore, they make drainage pipes perforated, i.e. "leaky" so that the water can go away by itself. And if drainage pipes are laid instead of sewer pipes, then these holes will quickly become clogged with house drains (“silt up, get fat”), and will not work. This is not to mention possible unpleasant odors along all 20 meters of the pipe. So better sewerage separately, and rainwater drainage separately.
I didn't quite understand the question, Vladimir. Inside the house, you put in fifty kopecks for the inside, i.e. PP pipe. You let her out into the street through the wall of the log house, just carefully “foam” the gaps, there should be no drafts. And then the transition to the 110th PVC, and you are already driving it. From the exit from the log house to the 110th PVC, you can start up the same fifty kopecks, only not far. For example, lower it with turns down to the foundation (it’s hard to say without imagining a possible route), then an oblique tee with a revision, just in case, into which to insert an eccentric transition from fifty dollars to a hundred. And I went 110th.
In principle, it is permissible to put fifty kopecks on the street “in plain sight” (if I understand correctly, this is the problem), but it is desirable that this is also a PVC pipe, otherwise there may be the same problems as “under the fence”. Yes, and you need to fasten it well and carefully, making gaps for thermal expansion. Fifty PVC PVC is sold, but not everywhere, you have to look.
And the general advice, just in case, is to avoid right angles. Make them, if necessary, prefabricated, for example, 45 plus 45, and inserts between them. Right angles clog well, but are difficult to clean.No, Vladimir, “old Soviet black pipes” are polypropylene, very rarely polyethylene low pressure, just the dye was different. Look in specialized stores, at construction sites, where they sell professional 4 and 6-meter sewer pipes, it is possible without sockets. I'll show you how to connect them, it's not difficult. The Internet has tips for everything. Look in the store at: Ufa, Oktyabrya Avenue, 97, All Instruments store. They promise three-meter 50 mm PVC for 202 rubles, however, for electricians. In extreme cases, you can also put 50 mm internal PP pipes, you just need to look after them. Check in the spring.
Hello again, Vladimir.
I ask your forgiveness. Having “surfed” the Internet in search of a fifty-kopeck piece of PVC, I really discovered that these pipes are only in St. Petersburg and Moscow, and not always of local production. I live almost in St. Petersburg. Therefore, well, put fifty dollars on PP, just look not for standard-cheap PP 1.8 mm, but 2.0 or 2.2 mm, at least some margin of safety. In principle, in non-responsible sections of the sewerage system, a fifty-kopeck piece of PP is installed without thinking about the consequences. You just have to keep an eye on this site, as I already wrote, mainly in the spring, at the opening of the summer season.
The PVC I found in Ufa are unlikely to fit, they are for protection electrical wires. Their wall thickness is only 1.5 mm. Why the search engine gave them to me as a sewer (!), Is a mystery to me. So do from home to the fence fifty dollars of PP. This is not possible, but if it is very necessary, then ...
thanks for useful article and adequate answers. I’ll start doing it tomorrow. I hope the pipe will not freeze in our Transbaikalia. Of course, I agree with you that you need to make a significant slope.
1. And what can happen to the 50th pipe? Silt up.-get fat-zamylitsya? Or will it crash hard?
2. Red (I mean for external wiring) or gray (for internal wiring), since it will be used only in summer? The store said that it is better to look for black (Soviet) -PVD -high pressure polyethylene. What do you say?
3. I have a plot with a slope. Along the fence just down the slope. I realized that it is better to dig in.
4. Soil - loam. And where does rainwater usually go from the roof? To another hole?
Thanks for answers. I will think.
And the last question:
It is impossible for me to go outside through the basement (floor slabs and 60 cm concrete blocks on the foundation).
I will just make holes in the side of the log house and then go on with external wiring. Accordingly, I do not want to make holes at 110. I will go out 50. 110 PVC will go along the ground.
And how to connect the exit through the log house and PVC-110 along the outer wall of the house? This is three meters in a straight line and all five with turns.
Yes, you got it right. It's just that not a single seller in stores (he went around about five) did not meet PVC-fifty. I will search further. From the exit from the log house to the location of the 110 pipe, I need to walk five fifty meters along the wall (check in the garage from below). We need to find PVC.
But the old Soviet black pipes that were laid earlier in apartments (50) are not PVC by any chance? They were still standing cisterns hung above the head
Thanks for the advice!
I know this store and have been there. This is an online store. All goods must be ordered and received upon arrival of the goods. I will definitely check out their website.
Just a passing question: I will finally find a fifty-kopeck piece of PVC pipe. But all sorts of turns and stuff also need PVC? This is probably unrealistic. I'll look online and on their website.
Thanks again for your attention.
Thank you for this article for the tips. I just had a situation that I bought myself a multistage pump. The plumber came and installed it. Everything worked like clockwork, no where not dug. When I got tired the next day and looked into the mine, there was water there and the water almost flooded the pump. And if I had a water outlet, then this would not have happened. You will need to redo your mine.
After arranging a local treatment plant, you should think about where to divert treated water. The constant call of a sewage truck is not the most financially profitable option, especially in the case of intensive use of autonomous sewage. There are several ways to organize a drain from a septic tank without violating the ecology of the site and the surrounding area.
the main task any septic tank - temporary accumulation of wastewater and their subsequent treatment. Such a structure can be made independently or purchased. ready product. In this case, the degree of wastewater treatment will depend on the complexity and technological equipment of this design. In this regard, septic tanks can be divided into several main types:
- Single-chamber sump (degree of purification< 70%). Это герметичная емкость, куда попадают стоки непосредственно из канализационной трубы. Под воздействием естественных процессов жидкие бытовые отходы разлагаются на ил, газ и осветленную воду. Ил скапливается на дне камеры, газовая фракция выводится в атмосферу с помощью air vent, and clarified water enters the filtering well, where it is subjected to soil post-treatment.
Single-chamber septic tank with soil aftertreatment
- Two-chamber sump (70-75%). This design consists of a primary and secondary clarifier. Heavy fractions settle to the bottom in the first chamber, and lighter organic compounds enter the second compartment, where they decompose under the influence of anaerobic bacteria. As in the first option, draining water from such a septic tank requires additional treatment.
Scheme of a two-chamber treatment plant
- Deep biological treatment (85-98%). Structurally, such septic tanks are a solid block consisting of several chambers and a number of special equipment. In addition to the standard settling stage, here the water is exposed to the action of aerobic bacteria, which require oxygen supplied by the compressor for their vital activity. This technology significantly accelerates the process of decomposition of organic compounds and increases the degree of water purification to very high rates.
Where to drain water from a septic tank: important nuances
There are several ways to remove clarified water:
- on relief;
- into the ground;
- into the reservoir.
In any of these cases pre-cleaning should be of good quality. First of all, this concerns total absence inorganic garbage. In addition, if the cleaning level does not exceed 70%, then the septic tank is drained only through additional filtration. It is forbidden to bring such water to the surface, given the high probability of contamination of the upper layers of the soil with harmful bacteria.
It's important to know. Anaerobic bacteria in the primary septic tanks contribute to the decomposition of organic matter with the release of heat and explosive gases. After exposure, silt remains, which contains pathogens of many infections. These residues must be regularly removed with a vacuum cleaner.
Sludge from the septic tank should be removed at least once a year
Stations for deep biological treatment allow water to be drained to the surface, since activated sludge based on aerobic microorganisms allows you to decompose dirt without releasing components harmful to the soil. Many manufacturers claim almost 100% efficiency of such structures and allow the discharge of purified water into the reservoir. However, with the organization of the drain from the septic tank to a natural source, some difficulties may arise, which will be discussed at the end of the article.
Discharge of clean water into a ditch
The easiest way to drain clarified water is to organize a drain from the septic tank into a ditch, pit or ravine, which are located next to the site. This option is usually used in dachas or in cottage villages with a low building density.
If the water meets sanitary standards, then the drain will not have a detrimental effect on the ecology of the surrounding area. On the other hand, there may be problems with neighbors. Not everyone will like the fact that, although cleaned, they will still flow next to their site. domestic waste. Therefore, the drain outlet is best positioned in such a way as not to cause discomfort to others.
For your information. Water withdrawal outside its territory may be limited based on the results of the general meeting of residents of the village. Based on this, it is better not to enter into conflict with neighbors, but to try to find a solution that satisfies all parties.
Before leading the drain directly into the ditch, it is advisable to equip an additional filtration zone. To do this, the drain from the septic tank is led into a filter trench with a drainage pipe, which is located below the freezing level of the soil and sprinkled with rubble.
Organization of draining water from a septic tank into a ditch: 1 - treatment plant; 2 - filtering trench with a drainage pipe; 3 - gravel-sand filter; 4 - ditch; 5 - groundwater level
Soil treatment options
If groundwater is located at a sufficient depth from the surface, then soil post-treatment of water can be applied. This drain option is often used for one- or two-chamber septic tanks, where the level of wastewater treatment is not high enough to bring to relief.
absorption well
The filter well can be made of brick, concrete rings, monolithic concrete and even car tires. The bottom in such a design is not concreted, but is covered by 30-40 cm with gravel or crushed stone. Clarified water from the septic tank with the help of a pipe enters the well, from where it seeps into the ground through a gravel cushion. The main condition, which, however, applies to all options for soil post-treatment, is that the filter zone should be at least 20 m from the source drinking water.
Scheme of installation of the absorption well
From a technical point of view, an infiltrator is the common name for all soil treatment devices. However, most often this term is understood as a specific type of structure, which is a hybrid of an absorption well and a filter trench. Such a drain from a septic tank has a wide filtration zone, which allows you to remove treated effluents even in conditions of low permeability of the soil.
Advice. If the soil does not absorb moisture well, which primarily applies to clay, it is necessary to increase the filtration area. To do this, you can use an infiltrator bigger size or use multiple designs.
The infiltrator allows you to remove wastewater in a larger volume than a simple absorption well
Filter field
Most effective way soil post-treatment is the use of a filtration field. This is a complex of filtering trenches, consisting of several drainage pipes connected to each other. This design allows you to remove and clean a large amount of liquid. And most importantly, the area of the zone is selected based on the needs of the consumer.
In order for the system to work more efficiently, a ventilation riser is installed at the end of each pipe. Thus, the field elements communicate with the atmosphere, which improves the cleaning process.
Typical design of the filtration field
Draining water into a natural reservoir
The owners of sites located in the immediate vicinity of a lake or river often have a question - is it possible to drain water from a septic tank directly into a reservoir? Manufacturers of some deep cleaning systems, such as Topas, Bioksi, etc., assure that the degree of purification is quite high, so that treated effluents can be discharged into a natural source without any problems. However, is everything so clear? On the one hand, cleaning at the level of 98% (again, according to manufacturers) meets sanitary standards. On the other hand, there are some points that make one think about the advisability of such an undertaking.
- Purified water must first be submitted for analysis. It must meet the standards for several dozen chemical substances.
- The local treatment plant will have to be officially registered as a separate facility.
- The operation of the septic tank will need to be constantly monitored so that its mode and operating conditions comply with technical standards.
Obtaining permission to discharge waste into a reservoir is accompanied by many bureaucratic procedures
What can be the conclusion? Theoretically, it is possible to drain water from a deep-cleaning septic tank into a reservoir after receiving official permission. In practice, few people are legalizing such a procedure. Many simply do not advertise their intentions, risking running into a large fine. In this situation, it is better to give preference to soil post-treatment or, on extreme case, organize a drain from the septic tank into a ditch. And the most correct option- turn to specialists. Then there will be no problems either with the quality of the drain or with the law.
Inquisitive minds often ask questions that not every layman will come up with. For example, where does the sewer go? And it's really, really interesting.
There are various rumors about this. Someone says that all city sewage flows directly into the river, so swimming on city beaches is not recommended.
Others argue that liquid waste goes underground through special drains, and there it is absorbed into the bowels of the soil.
However, if we only imagine how many millions of cubic meters the inhabitants emit every day, then there will not be enough soil to “suck” it into themselves.
We have prepared for you interesting facts and photos about what happens to the sewer after it leaves our house.
Where does the sewer go?
It is unlikely that anyone wonders where the waste that we flush into sewer pipes goes. And they have a long journey ahead of them.
First of all, it must be said that enterprises use their own, individual cleaning system. That is, the waste of large factories is not connected with the city sewerage.
As a rule, such a system has a cycle: water is used for technical purposes, then it goes to treatment, and then it returns to the workshop for the next use.
Everything is clear here. What about the city sewer? As an example, we decided to take Moscow.
Often in our time, one can hear indignation about the fact that the Moscow River will soon turn into a swamp due to the fact that millions of tons of sewage household waste from the city and even enterprises flow into it almost directly.
In fact, everything is not so simple. If this were true, then the Moskva River would long ago become a real sump, and everyone who swims there would become infected with various sores.
It must be emphasized right away that the waste of human life in liquid form flows into special treatment facilities that are available in every city. This is the key point.
What happens to the sewer in the end
In a nutshell, it can be described as follows. When liquid waste from the city sewer flows into the sewage treatment plant, it goes through the primary treatment stage, which precipitates sludge.
You'll be surprised but it's real interesting fact: then they make ... gas from this sludge.
Schematically, the sewage treatment process is as follows:
So, at the very beginning, sewage enters the cleaning system through giant pipes. Traffic is approximately 2.5 million cubic meters per day:
Now the water enters the first settling tank, where it stays for exactly two hours. During this time, the settled organic matter is sent to the production of biogas, and the rest - further along the system:
This is the second sump:
In general, there is a constant analysis of water coming from the drains of the city, piped and purified:
And only after such a thorough purification, the water enters the Moscow River directly from this reservoir:
Now you know where all the Moscow sewerage flows and what happens to sewage and other sewage. Approximately the same principle of cleaning work all the cities of the world.
Otherwise, the very existence of megacities would be impossible.
By the way, read - you will learn a lot of amazing things. We also recommend subscribing to . It's always interesting with us!
When there were far fewer people on the globe than today, used water and waste was drained from homes and industries through sewers and dumped into large bodies of water. Wastewater disposal in those days consisted in the fact that the effluent was allowed to mix with salt or fresh water, which was supposed to dilute them.
Today, in our overpopulated, highly developed world, wastewater must undergo a process of purification in order not to poison the world's water supply. During the decomposition (decay) of waste - under the action of bacteria - a large amount of oxygen is consumed, and if such decomposition took place in a river or lake, then the plants and animals living in them would lack the gases necessary for life - oxygen and carbon dioxide. Some types of waste, such as human and animal excrement, also contain harmful bacteria. If such bacteria accumulate in large quantities and people come into contact with them, it can cause infectious diseases.
So when you flush a toilet or flush dirty water down the drain, the wastewater is sent to a wastewater treatment plant. This is to protect you and environment. Wastewater is piped from your home into larger sewer pipes underground—sometimes so large that the sewage flows like a river. (It happens that accumulated underground and storm water.) On the way to the treatment plant, wastewater from residential buildings and industrial enterprises of the settlement merges into one stream.
(In some communities, where homes and businesses are, or were once, far apart, and where sewerage systems are virtually unprofitable to maintain, sewage is often dumped into huge septic tanks—colossal reservoirs installed underground near each household. Most sewage decomposes in septic tanks under the action of bacteria, but these tanks have to be emptied and cleaned quite often.)
When wastewater enters the treatment plant, it is filtered through a large metal grate. This grid separates large items that cannot be recycled. Small stones and sand are also filtered out. After cleaning and drying, these materials can be used in construction and road repair. After that, the “fragrant”, soup-like wastewater, passed through the grate, enters a huge sump tank, where solid particles eventually sink to the bottom. This dirty sediment enters a special treatment tank where bacteria feed on it, converting it into harmless substances.
During this decomposition, methane gas is formed. This gas is used as a fuel to produce steam, which powers the pumps in the wastewater treatment plant. The sludge resulting from these processes is rich in nutrients and can be used as fertilizer.
The liquid part of the wastewater after separating the sediment is fed to the filter loading, where it is cleaned. Here, cleaning takes place in this way: water seeps through a layer of loading - stones covered with bacteria, and the bacteria eat all the remaining waste. clean water, which is obtained as a result of this whole process, is dumped into rivers, lakes or seas.
