With the help of sewerage treatment facilities, household, atmospheric and industrial wastewater is removed. Errors in their design and construction are fraught with many negative consequences.

How does sewage work?

Local sewage treatment plants consist of a number of separate modules.

Despite the fact that the set of blocks may differ, the operating algorithm for all systems is the same:

1. First, the wastewater entering the facility undergoes mechanical treatment. This allows you to extract large particles of mineral and organic origin. The devices used are the simplest - gratings and sieves. To filter smaller fractions (glass waste, sand, slag), sand traps are used. Thanks to membrane devices, more thorough cleaning is achieved. The settling tank allows you to identify suspended components - mainly mineral impurities.
2. Next, biological treatment facilities come into operation. To decompose organic compounds into individual components, highly active bacteria are used. Liquid components pass through a biofilter, which makes it possible to obtain sludge and gaseous compounds.
3. The last stage of operation of local sewage treatment facilities is chemical disinfection of waste. From the point of view of sanitary standards, the liquid coming out is quite suitable for technical use.

Types of sewer systems

The development of local treatment facilities is carried out before the main construction activities take place. Before design begins, the most optimal system is selected, taking into account its purpose, the nature of the wastewater and its volume.

Let's look at how the sewer system works in the city. Currently, there are the following types of treatment facilities:

• Local.
• Individual (autonomous).
• Blocks and modules.

Local treatment facilities

The local type of treatment facilities allows you to collect and treat wastewater at individual sites. Depending on the type of buildings served, local systems are divided into household and industrial. The traditional design of treatment facilities involves a gradual decrease in the speed of wastewater as it moves away from the discharge point. In this case, solid fractions gradually precipitate, forming plaque at the bottom of the pipe. To remove remaining impurities, post-treatment systems are used.

The operating principle of classical type sewerage treatment facilities implies the presence of sufficiently large containers (or settling tanks). They are needed to settle waste. Such treatment plant systems are practically not used to equip small private buildings. Experience in the operation of local treatment facilities has shown that these structures are most suitable for small settlements that do not have centralized sewer lines.

Septic tanks

These devices are widely used in the construction of autonomous sewage treatment plants. As a rule, we are talking about country houses. It is important to understand the operating principle of an autonomous sewer system if you are going to make or maintain it yourself.

The structures themselves are plastic tanks and have a number of useful qualities:

• Light weight. This facilitates the transportation and installation of septic tanks. No special lifting equipment is required.
• Resistance to aggressive environments. The drainage contained inside does not damage the containers.
• Inert to corrosion. A septic tank covered with earth does not rust.
• Good strength characteristics.

Manufacturers of septic tanks provide instructions on what the treatment plant consists of. Inside the container there can be a different number of sections, each of which performs a separate function. These can be settling tanks, biological or mechanical filters. Private treatment facilities are usually equipped with septic tanks. They are very easy to maintain and operate, offering excellent durability. The sewerage system can be completely autonomous. To improve the degree of waste purification, additional sections are introduced into the design of treatment facilities. The most popular option is filtration and aeration fields.

Aero tanks

These devices are part of large industrial sewage treatment plants. Their function is to recycle industrial and industrial waste. Aerotanks are large-volume containers in which water is mixed with activated sludge.

To increase the reaction rate, the slurry is enriched with oxygen. There are cases when aeration tanks are included in the autonomous sewer systems of suburban buildings. For these purposes, portable tanks have been developed, which for convenience are installed inside septic tanks. To increase the efficiency of aeration tanks, they can be equipped with special traps that allow fat and oil products to be removed from waste.

Biological filters

Sewage structures often contain biological filters. As a rule, we are talking about built-in elements. Biofilters usually enhance local treatment systems. The main active substance for biological filtration is special bacteria, which significantly speeds up the process of waste decomposition. The result is fairly clean water, which does not contain components harmful to the environment. It is allowed to be drained into the ground or the nearest body of water.

Showers

The purpose of treatment facilities is to remove harmful inorganic and organic impurities from wastewater. After this, the filtered water can be used to irrigate cities and fields. Collection, transportation and purification of melt and rainwater is carried out through a storm sewer system. Traditional sewer lines are not designed for these purposes.

Thanks to the storm sewer treatment system, the protection of foundations, road surfaces and lawns is achieved. If everything is done correctly, the garden area will not flood in the spring and during heavy rains. Excess water is drained into a common collector through a system of gutters and pipes. According to the regulations, the storm drain must be installed below the frost freezing level so that it can function uninterruptedly at any time of the year. The system includes filters to eliminate small fractions (sand, glass particles, stone chips, etc.). As a result, the collector receives purified water.

In cases where more refined wastewater treatment is required, water treatment facilities are supplemented with sorption modules and oil product removal filters. This makes it possible to achieve such a level of waste purity that the finished liquid can be poured into reservoirs or used to irrigate vegetable gardens and flower beds. Maintenance of stormwater structures involves periodic replacement of filtration cartridges.

Autonomous systems

By design, autonomous sewer systems are very similar to local wastewater treatment plants. Although there are certainly certain differences. This type of wastewater treatment facilities includes septic tanks and waste accumulation tanks. First, wastewater accumulates inside the system, and then undergoes a filtration procedure.

Blocks and modules

Thanks to block and modular types of treatment facilities, deeper waste treatment is achieved. As a rule, plants, factories and industrial workshops are equipped with structures of this type.

The use of blocks and modules allows you to achieve the following goals:

• High quality of the final cleaning result.
• Reducing the percentage of silt deposits in purified water.
• Protecting the environment from harmful influences.
• Possibility of reuse of purified water.

Block and modular systems are superior to the simplest treatment plants in terms of efficiency and productivity. Their potential is quite enough to serve all the houses in the area. Blocks and modules cope well with temperature fluctuations and can be used in areas with harsh climates.

Which option is better

In order to decide on the type of treatment system, it is recommended to focus on the following criteria:

1. The total volume of wastewater generated by this facility during the day.
2. Where are the treatment facilities located - underground or on its surface. Areas with high groundwater levels require the use of surface communications.
3. What do treatment plants consist of: a list of individual sections is usually contained in the accompanying instructions.
4. Specifics of installation of treatment facilities. Plastic septic tanks are most suitable for self-installation.

Some varieties operate completely autonomously. Other models of sewage treatment plants require electrical power. During construction, it is necessary to take into account existing sanitary standards. Those structures that are serviced by a sewer truck need to be provided with free access.

Design specifics

In the process of drawing up a design for treatment structures, all risks that could affect the efficiency of the system must be calculated. Accounting is also required by the existing legislative framework, which spells out all the basic requirements for protecting the natural environment. Treatment facilities are permitted to be located exclusively within sanitary protected zones.

As you work on the project, keep the following points in mind:

• Dimensions and volume of the system.
• The most suitable model.
• Depth of groundwater passage.
• The level of ground freezing on the site.
• Module performance.
• Type of cleaning devices.
• Specifics of installation activities.

To avoid claims from sanitary and licensing authorities, you should acquire a number of documents:

• Agreement on the purchase or lease of land.
• Installation drawing of communications and system blocks.
• Results of checks and inspections.
• Technical conditions for the exploitation of water resources.
• Information about the amount of water consumption.
• Detailed description of treatment facilities.

Any violation of sanitary regulations is fraught with monetary and administrative penalties.

Modern ecology, alas, leaves much to be desired - all pollution of biological, chemical, mechanical, organic origin sooner or later penetrates the soil and water bodies. The supply of “healthy” clean water is becoming smaller every year, in which the constant use of household chemicals and the active development of production play a certain role. The wastewater contains a huge amount of toxic impurities, the removal of which must be complex and multi-level.

Different methods are used for water purification - the optimal choice is made taking into account the type of contaminants, desired results, and available capabilities.

The simplest option is . It is aimed at removing insoluble components that pollute water - these are fats and solid inclusions. First, the wastewater passes through grates, then sieves and ends up in settling tanks. Small components are deposited in sand traps, petroleum products are deposited in gasoline and oil traps, and in grease traps.

A more advanced cleaning method is membrane. It guarantees the most precise removal of contaminants. involves the use of appropriate organisms that oxidize organic inclusions. The basis of the technique is the natural purification of reservoirs and rivers at the expense of their population with beneficial microflora that removes phosphorus, nitrogen and other unnecessary impurities. The biological cleaning method can be anaerobic or aerobic. Aerobic requires bacteria, the life of which is impossible without oxygen - biofilters and aeration tanks filled with activated sludge are installed. The degree of purification and efficiency is higher than for a biofilter for wastewater treatment. Anaerobic purification does not require access to oxygen.

It involves the use of electrolysis, coagulation, as well as the precipitation of phosphorus with metal salts. Disinfection is carried out by ultraviolet irradiation, chlorine treatment, and ozonation. Disinfection with ultraviolet irradiation is a much safer and more effective method than chlorination, since it is carried out without the formation of toxic substances. UV radiation is harmful to all organisms, therefore it destroys all dangerous pathogens. Chlorination is based on the ability of active chlorine to act on microorganisms and destroy them. A significant drawback of the method is the formation of chlorine-containing toxins, carcinogenic substances.

Ozonation involves the disinfection of wastewater with ozone. Ozone is a gas with a triatomic molecular structure, a strong oxidizing agent that kills bacteria. The technique is expensive and is used to release ketones and aldehydes.

Thermal recovery is optimal for treating process wastewater when other methods are not effective. At modern treatment complexes, wastewater undergoes multi-component step-by-step treatment.

Wastewater treatment plants: requirements for treatment systems, types of treatment facilities

Primary mechanical treatment is always recommended, followed by biological treatment, additional treatment and disinfection of wastewater.

• For mechanical cleaning, rods, gratings, sand traps, homogenizers, settling tanks, septic tanks, hydrocyclones, centrifuges, flotation units, and degassers are used.
• A sludge pump is a special device for purifying water with activated sludge. Other components of the biotreatment system are biocoagulators, suction pumps, aeration tanks, filters, secondary settling tanks, sludge separators, filtration fields, and biological ponds.
• As part of post-treatment, neutralization and filtration of wastewater is used.
• Disinfection and disinfection are carried out by chlorine and electrolysis.

What is meant by wastewater?

Wastewater is water masses contaminated with industrial waste, for the removal of which from the areas of settlements and industrial enterprises appropriate sewer systems are used. Runoff also includes water formed as a result of precipitation. Organic inclusions begin to rot en masse, which causes deterioration in the condition of water bodies and air, and leads to the massive spread of bacterial flora. For this reason, important tasks of water treatment are the organization of drainage, wastewater treatment, and the prevention of active harm to the environment and human health.

Indicators of the degree of purification

The level of wastewater pollution must be calculated taking into account the concentration of impurities, expressed as mass per unit volume (g/m3 or mg/l). Domestic wastewater is a uniform formula in terms of composition; the concentration of pollutants depends on the volume of water mass consumed, as well as consumption standards.

Degrees and types of pollution of domestic wastewater:

• insoluble, large suspensions are formed in them, one particle cannot be more than 0.1 mm in diameter;
• suspensions, emulsions, foams, the particle sizes of which can range from 0.1 microns to 0.1 mm;
• colloids – particle sizes in the range of 1 nm-0.1 microns;
• soluble with molecularly dispersed particles, the size of which is no more than 1 nm.

Pollutants are also divided into organic, mineral, and biological. Mineral - these are slags, clay, sand, salts, alkalis, acids, etc. Organic - plant or animal, namely the remains of plants, vegetables, fruits, vegetable oils, paper, feces, tissue particles, gluten. Biological impurities – microorganisms, fungi, bacteria, algae.

Approximate proportions of pollutants in household wastewater:

• mineral – 42%;
• organic – 58%;
• suspended matter – 20%;
• colloidal impurities – 10%;
• dissolved substances – 50%.

The composition of industrial wastewater and the level of its pollution are indicators that vary depending on the nature of a particular production and the conditions for using wastewater in the technological process.

Atmospheric runoff is affected by climate, terrain, the nature of buildings, and the type of road surface.

The operating principle of cleaning systems, rules for their installation and maintenance. Requirements for cleaning systems

Water treatment facilities must provide the specified epidemic and radiation indicators and have a balanced chemical composition. After entering water treatment facilities, water undergoes complex biological and mechanical purification. To remove debris, wastewater is passed through a screen with rods. Cleaning is automatic, and operators also check the quality of contaminant removal every hour. There are new self-cleaning grilles, but they are more expensive.

For clarification, clarifiers, filters, and settling tanks are used. In settling tanks and clarifiers, water moves very slowly, as a result of which suspended particles begin to fall out to form sediment. From the sand traps, the liquid is directed to the primary settling tanks - mineral impurities also settle here, and light suspensions rise to the surface. The sediment is formed at the bottom; it is raked into pits using a truss with a scraper. The floating substances are sent to the grease trap, from there to the well and rolled away.

The clarified water masses are sent to patches, then to aeration tanks. At this point, the mechanical removal of impurities can be considered complete - the turn of the biological one comes. The aeration tanks include 4 corridors, into the first one silt is supplied through tubes, and the water acquires a brown tint, continuing to be actively saturated with oxygen. The sludge contains microorganisms that also purify the water. The water is then sent to a secondary settling tank where it is separated from the sludge. The sludge goes through pipes into wells, from where pumps pump it into aeration tanks. Water is poured into contact-type tanks, where it was previously chlorinated, but now in transit.

It turns out that during primary purification, water is simply poured into a vessel, infused and drained. But this is precisely what makes it possible to remove most of the organic impurities at minimal financial cost. After water leaves the primary settling tanks, it goes to other water treatment facilities. Secondary purification involves the removal of organic residues. This is a biological stage. The main types of systems are activated sludge and trickling biological filters.

Operating principle of the wastewater treatment complex (general characteristics of water treatment facilities)

Through three collectors from the city, dirty water is supplied to mechanical screens ( the optimal gap is 16 mm), passes through them, the largest contaminant particles are deposited on the grid. Cleaning is automatic. Mineral impurities, which have a significant mass compared to water, follow through the hydraulic elevators, after which the hydraulic elevators are rolled back to the launch pads.

After leaving the sand traps, the water enters the primary settling tank (there are 4 in total). The floating substances are fed into the grease trap, from the grease trap into the well and rolled away. All operating principles described in this section are valid for different types of treatment systems, but may have certain variations taking into account the characteristics of a particular complex.

Important: types of wastewater

To choose the right treatment system, be sure to consider the type of wastewater. Available options:

1. Household fecal or household waste - they are removed from toilets, bathrooms, kitchens, baths, canteens, hospitals.
2. Industrial, production, involved in the performance of various technological processes such as washing of raw materials, products, cooling of equipment, pumped out during mining.
3. Atmospheric wastewater, including rainwater, meltwater, and those remaining after watering streets and green plantings. The main pollutants are mineral.

The Village continues to explain how the things that citizens use every day work. In this issue - the sewerage system. After we press the flush button on the toilet, turn off the tap and go about our business, tap water turns into waste water and begins its journey. To re-enter the Moscow River, it needs to go through kilometers of sewer networks and several stages of cleaning. The Village learned how this happens after visiting the city's wastewater treatment plants.

Through the pipes

At the very beginning, water enters the internal pipes of the house with a diameter of only 50–100 millimeters. Then it goes along the network a little wider - the courtyards, and from there - to the street ones. At the border of each yard network and at the point where it transitions to the street network, an inspection well 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 a pipe in a water park.

Basically, due to the depth and natural topography of the territory, water flows through the pipes on its own, but in some places pumping stations are required, there are 156 of them in Moscow.

Wastewater goes to one of four treatment plants. The cleaning process is continuous, and peaks in hydraulic load occur at 12 noon and 12 noon. The Kuryanovsky treatment plant, which is located near Maryin and is considered one of the largest in Europe, receives water from the southern, southeastern and southwestern parts of the city. Sewage from the northern and eastern parts of the city goes to the treatment plant in Lyubertsy.

Treatment

Kuryanovsky treatment facilities are designed for 3 million cubic meters of wastewater per day, but only one and a half are received here. 1.5 million cubic meters is 600 Olympic swimming pools.

Previously, this place was called an 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 whether 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 blocks. In addition, there is a whole complex of facilities for processing sediments that are formed in the process.

Mechanical cleaning

Turbid and foul-smelling wastewater arrives at the treatment plant warm. Even in the coldest time of the year, its temperature does not drop below plus 18 degrees. Wastewater is met by a receiving and distribution chamber. But we won’t see what’s happening there: the chamber was completely closed so that the smell wouldn’t spread. By the way, the smell of the huge (almost 160 hectares) wastewater treatment area is quite tolerable.

After this, the mechanical cleaning stage begins. Here, special grates trap debris that floats along with the water. Most often these are rags, paper, personal hygiene products (wipes, diapers), and also food waste - for example, potato peelings and chicken bones. “You won’t meet anything. It happened that bones and skins arrived from meat processing plants,” they say with a shudder at the treatment plants. The only pleasant thing was gold jewelry, although we did not find any eyewitnesses of such a catch. Seeing the debris-retaining grate is the most terrifying part of the excursion. In addition to all sorts of nasty things, there are many, many lemon slices stuck in it: “You can guess the time of year by the contents,” the employees note.

A lot of sand comes with wastewater, and to prevent it from settling on structures and clogging pipelines, it is removed in sand traps. Sand in liquid form is supplied to a special area, where it is washed with industrial water and becomes ordinary, that is, suitable for landscaping. Treatment plants use sand for their own needs.

The stage of mechanical cleaning in the primary settling tanks is completed. These are large tanks in which fine suspended matter is removed from the water. The water comes here cloudy and leaves cleared.

Biological treatment

Biological treatment begins. It occurs in structures called aeration tanks. They artificially support the vital activity of a community of microorganisms called activated sludge. Organic contaminants in water are the most desirable food for microorganisms. Air is supplied to the aeration tanks, which prevents the sludge from settling so that it comes into contact with wastewater as much as possible. This continues for eight to ten hours. “Similar processes occur in any natural body of water. The concentration of microorganisms there is hundreds of times lower than what we create. Under natural conditions, this would last for weeks and months,” says Isakov.

An aeration tank is a rectangular tank divided into sections in which waste water snakes. “If you look through a microscope, everything there is crawling, moving, moving, swimming. We force them to work for our benefit,” says our guide.

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 to the bottom, is collected by suction 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 is filtered through a very fine sieve, and then discharged into the station’s outlet channel, 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 tint. This is a modern and largest such block in the world. Although the old project did not have it, previously they wanted to disinfect the water with liquid chlorine. “It’s good that it didn’t come to that. We would destroy every living thing in the Moscow River. The reservoir would be sterile, but dead,” says Vadim Gelievich.

In parallel with water purification, the station deals with sediment. Sludge from primary settling tanks and excess activated sludge are processed together. They enter digesters, where at a temperature of plus 50–55 degrees, the fermentation process takes place 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 complexes outside the Moscow Ring Road. “30–40 years ago, sediment was dried on sludge beds under natural conditions. This process lasted from three to five years, but now dehydration is instantaneous. The sludge itself is a valuable mineral fertilizer; in Soviet times it was popular, state farms gladly took it. 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 into water and biogas, saving on disposal costs. Part of the biogas is burned in the boiler room, and part is sent to the combined heat and power plant. A thermal power plant is not an ordinary element of a wastewater treatment plant, but rather a useful addition that gives treatment plants relative energy independence.

Fish in the sewer

Previously, on the territory of the Kuryanovsky treatment plant there was an engineering center with its own production base. Employees carried out unusual experiments, for example, breeding sterlet and carp. Some of the fish lived in tap water, and some in sewer water, which had been treated. Nowadays, fish are found only in the discharge canal; there are even signs saying “Fishing is prohibited.”

After all the purification processes, the water flows through the discharge canal - a small river 650 meters long - into the Moscow River. Here and wherever the process takes place in the open air, many seagulls swim on the water. “They don’t interfere with the processes, but they spoil the aesthetic appearance,” Isakov is sure.

The quality of treated wastewater discharged into the river is much better than the water in the river in all sanitary indicators. But drinking such water without boiling is not recommended.

The volume of treated wastewater is equal to approximately a third of all water in the Moscow River above the discharge. If the treatment plants failed, downstream settlements would be on the verge of environmental disaster. But this is practically impossible.

This subsidiary of the petrochemical company SIBUR is one of the largest producers of high-quality rubbers, latexes and thermoplastic elastomers in Russia.

01 . Our guide to the world of high technologies for wastewater, process and, of course, sewage water treatment, press officer Ksenia deals with security. After a slight hitch, we are still allowed into the territory.

02 . Exterior view of the complex. Part of the cleaning process takes place inside the building, but some stages are also outdoors.

03 . Let me make a reservation right away that this complex processes only wastewater from Voronezhsintezkauchuk and does not touch the city sewerage system, so readers who are chewing at the moment, in principle, do not have to worry about their appetite. When I learned about this, I was somewhat upset, because I wanted to ask the staff about mutant rats, corpses and other horrors. So, one of two supply pressure pipelines with a diameter of 700 mm (the second is a reserve one).

04 . First of all, wastewater enters the mechanical treatment area. It includes 4 Rotamat Ro5BG9 mechanical wastewater treatment units from HUBER (3 in operation, 1 in reserve), combining fine-slit drum screens and highly efficient aerated sand traps. Waste from the grates and sand after squeezing are fed using conveyors into bunkers with a sluice gate. The waste from the grates is sent to a landfill, but can also be used as filler in sludge composting. Sand is stored on special sand sites.

05 . In addition to Ksenia, we were accompanied by the head of the workshop, Alexander Konstantinovich Charkin. He said that he didn’t like to be photographed, so I clicked him, just in case, as he enthusiastically told us how sand traps work.

06 . In order to smooth out the uneven flow of industrial wastewater from an enterprise, it is necessary to average the wastewater by volume and composition. Therefore, due to cyclic fluctuations in the concentration and composition of pollutants, the water then ends up in so-called homogenizers. There are two of them here.

07 . They are equipped with systems for mechanical mixing of wastewater. The total capacity of the two homogenizers is 7580 m3.

08 . You can try to blow off the foam.

09 . After averaging by volume and composition, wastewater is supplied to flotation tanks for treatment using submersible pumps.

10 . Flotators are 4 flotation units (3 in operation, 1 in reserve). Each flotator is equipped with a flocculator, a thin-layer sedimentation tank, control, measuring and dosing equipment, an air compressor, a recirculation water supply system, etc.

11 . They saturate part of the water with air and supply a coagulant to remove latex and other suspended substances

12 . Pressure flotation allows light suspended solids or emulsions to be separated from the liquid phase using air bubbles and reagents. Aluminum hydroxychloride (about 10 g/m3 of wastewater) is used as a coagulant.

13 . To reduce reagent consumption and increase flotation efficiency, a cationic flocculant is used, for example, Zetag 7689 (about 0.8 g/m3).

14 . Mechanical sludge dewatering workshop (MSD). Here, sludge from flotation tanks and activated sludge after biological treatment and post-treatment are dewatered.

15 . Mechanical dewatering of sludge is carried out on belt filter presses (belt width 2 m) with the addition of a working solution of a cationic flocculant. In emergency situations, sludge is supplied to emergency sludge sites.

16 . The dehydrated sludge is sent for disinfection and further drying to a turbo dryer (VOMM Ecologist-900) with a final humidity of 20%, or to storage areas.

17 .

18 . The filtrate and dirty wash water are drained into the dirty water tank.

19 . Unit for preparing and dosing the flocculant working solution.

20 . Behind the green door from the previous photo is an autonomous boiler room.

21 . Biological treatment according to the project is carried out in biotanks using loading material KS-43 KPP/1.2.3 produced by Ecopolymer. Biotanks are 2-corridor with a corridor size of 54x4.5x4.4 m (each capacity is 2100 m3). With transverse sectioning by installing lightweight partitions. With the placement of containers with carriers of fixed biomass and a polymer aeration system. Unfortunately, I completely forgot to take a closer photo of them.

22. Blower station. Equipment – ​​centrifugal blowers Q = 7000 m3/h, 3 pcs. (2 – in operation, 1 – in reserve). Air is used for aeration and regeneration of biotanks loading, as well as washing of post-treatment filters.

23 . Post-treatment is carried out using fast, non-pressure sand filters.

24 . Number of filters – 10 pcs. The number of sections in the filter is two. Dimensions of one filter section: 5.6x3.0 m.
The useful filtering area of ​​one filter is 16.8 m2.

25 . Filter media – quartz sand with an equivalent diameter of 4 mm, layer height – 1.4 m. The amount of loading material per filter is 54 m3, the volume of gravel is 3.4 m3 (unfractionated gravel with a height of 0.2 m).

26 . Next, the treated wastewater undergoes disinfection using a UV installation TAK55M 5-4x2i1 (option with post-treatment) manufactured by Wedeco.

27 . The installation capacity is 1250 m3/h.

28 . Wash waters from biotanks, rapid filters, sludge water from sludge compactors, filtrate, and wash waters from the central treatment facility are accumulated in the dirty water reservoir.

29 . Perhaps this is the most colorful place we have seen =)

30 . From the reservoir, water is supplied to radial settling tanks for clarification. They are used to clarify wastewater from on-site sewage systems: filtrate and wash water from mechanical dewatering of sludge, effluent from emptying biotanks during regeneration, dirty wash water from rapid post-treatment filters, sludge water from compactors. Clarified water is sent to biotanks, sediment - to the sludge compactor (in emergency situations - directly to the sediment mixing tank in front of the central treatment center). Removal of floating substances is maintained.

31 . There are two of them. One was full and fragrant.

32. And the second one was actually empty.

33 . MCC

34 . Operator.

35 . Basically, that's all. The cleaning process is complete. After UV disinfection, the water flows into a collection chamber, and from it through a gravity collector further to the point of discharge into the Voronezh Reservoir. The described technological process fully ensures the fulfillment of the requirements for the quality of treated wastewater discharged into a surface reservoir for fishery purposes. And let this picture serve as a group photo as a souvenir for the excursion participants.

Apartment and private buildings, enterprises and service establishments use water, which, after passing through sewer lines, must be brought to the required level of purity, then sent for reuse or discharged into rivers. In order not to create a dangerous environmental situation, treatment facilities have been created.

Definition and purpose

Treatment facilities are complex equipment that is designed to solve the most important problems - ecology and human health. The amount of waste is constantly increasing, new types of detergents are appearing, which are difficult to remove from water so that it is suitable for further use.

The system is designed to receive a certain volume of wastewater from a city or local sewerage system, purify it from all kinds of impurities and organic substances and then send it to natural reservoirs using pumping equipment or the gravity method.

Principle of operation

During operation, the treatment station frees water from the following types of contaminants:

• organic (feces, food residues);
• mineral (sand, stones, glass);
• biological;
• bacteriological.

The greatest danger is posed by bacteriological and biological impurities. As they decompose, they release dangerous toxins and unpleasant odors. If the level of purification is insufficient, an epidemic of dysentery or typhoid fever may occur. To prevent such situations, water after a full cleaning cycle is checked for the presence of pathogenic flora, and only after examination is discharged into reservoirs.

The principle of operation of treatment facilities is the gradual separation of garbage, sand, organic components, and fat. The semi-purified liquid is then sent to settling tanks containing bacteria, which digest the smallest particles. These colonies of microorganisms are called activated sludge. Bacteria also release their waste products into the water, so after they have disposed of organic matter, the water is cleared of bacteria and their waste.

In the most modern equipment, almost waste-free production occurs - sand is caught and used for construction work, bacteria are compressed and sent to the fields as fertilizer. The water goes back to consumers or into the river.

Types and design of treatment facilities

There are several types of wastewater, so the equipment must match the quality of the incoming liquid. Highlight:

• Household waste is used water from apartments, houses, schools, kindergartens, and catering establishments.
• Industrial. In addition to organic matter, they contain chemicals, oil, and salts. Such waste requires proper treatment methods as bacteria cannot cope with the chemicals.
• Rain. The main thing here is to remove all debris that is washed down the drain. This water is less polluted with organic matter.

Based on the volume served by the treatment plant, the stations are:

• urban - the entire volume of wastewater is sent to facilities with enormous throughput and area; located away from residential areas or made closed so that the smell does not spread;
• VOC – local treatment plant, serving, for example, a holiday village or village;
• septic tank - a type of VOC - serves a private house or several houses;
• mobile installations that are used as needed.

In addition to complex structures, such as biological treatment stations, there are more primitive devices - grease traps, sand traps, grates, sieves, settling tanks.

Construction of a biological treatment station

Stages of water purification at wastewater treatment plants:

• mechanical;
• primary settling tank;
• aeration tank;
• secondary settling tank;
• post-treatment;
• disinfection.

At industrial enterprises, the system is additionally equipped with containers with reagents and special filters for oils, fuel oil and various inclusions.

When waste is received, it is first cleaned of mechanical impurities - bottles, plastic bags and other debris. Next, the wastewater is passed through a sand trap and grease trap, then the liquid enters the primary settling tank, where large particles settle to the bottom and are removed by special scrapers into the bunker.

Next, the water is sent to the aeration tank, where organic particles are absorbed by aerobic microorganisms. In order for bacteria to multiply, additional oxygen is supplied to the aeration tank. After clarification of wastewater, it is necessary to dispose of the excess mass of microorganisms. This happens in a secondary settling tank, where colonies of bacteria settle to the bottom. Some of them are returned to the aeration tank, the excess is compressed and removed.

Post-treatment is additional filtration. Not all facilities have filters - carbon or membrane, but they allow you to completely remove organic particles from the liquid.

The last stage is exposure to chlorine or ultraviolet light to destroy pathogens.

Water purification methods

There are a large number of methods by which you can clean wastewater - both domestic and industrial:

• Aeration is the forced saturation of wastewater with oxygen to quickly remove odors, as well as for the proliferation of bacteria that decompose organic matter.
• Flotation is a method based on the ability of particles to be retained between gas and liquid. Foam bubbles and oily substances lift them to the surface, from where they are removed. Some particles can form a film on the surface that can be easily drained or collected.
• Sorption is a method of absorption by some substances of others.
• Centrifuge is a method that uses centrifugal force.
• Chemical neutralization, in which the acid reacts with an alkali, after which the precipitate is disposed of.
• Evaporation is a method in which heated steam is passed through dirty water. Volatile substances are removed along with it.

Most often, these methods are combined into complexes to carry out cleaning at a higher level, taking into account the requirements of sanitary and epidemiological stations.

Design of treatment systems

The design of treatment facilities is designed based on the following factors:

• Groundwater level. The most important factor for autonomous treatment systems. When installing a septic tank with an open bottom, the wastewater, after settling and biological treatment, is removed into the ground, where it enters the groundwater. The distance to them should be sufficient so that the liquid is cleared as it passes through the soil.
• Chemical composition. From the very beginning, it is necessary to know exactly what waste will be cleaned and what equipment is needed for this.
• Soil quality, its penetrating ability. For example, sandy soils absorb liquid faster, but clay areas will not allow wastewater to be disposed of through an open bottom, which will lead to overflow.
• Waste removal – entrances for vehicles that will service the station or septic tank.
• Possibility of draining clean water into a natural reservoir.

All treatment facilities are designed by special companies that are licensed to carry out such work. A permit is not required to install a private sewer system.

Installation of installations

When installing water treatment facilities, many factors must be taken into account. First of all, this is the terrain and system performance. It is necessary to expect that the volume of wastewater will constantly increase.

The stable operation of the station and the durability of the equipment will depend on the quality of the work performed, so public facilities need to be well designed, taking into account all the features of the given area and the configuration of the system.

1. Creating a project.
2. Site inspection and preparatory work.
3. Installation of equipment and connection of units.
4. Setting up station control.
5. Testing and commissioning.

The simplest types of autonomous sewerage require the correct slope of the pipes so that the line does not become clogged.

Operation and Maintenance

It is necessary to regularly check the quality of water purification

Planned maintenance prevents serious accidents, so large treatment plants have a schedule according to which units and the most significant components are regularly repaired, and parts that fail are replaced.

At biological treatment plants, the main points requiring attention are:

• amount of activated sludge;
• oxygen level in water;
• timely removal of garbage, sand and organic waste;
• control of the final level of wastewater treatment.

Automation is the main link that is involved in the work, so checking electrical equipment and control units by a specialist is a guarantee of uninterrupted operation of the station.