Overview of the septic tank for giving “Tank”: how it works, advantages and disadvantages of the system

Nikolay Fedorenko
Checked by a specialist: Nikolay Fedorenko
Author: Tatyana Lavrova
Last update: March 2019

A modern country house is not inferior in comfort to a city apartment. It has a toilet, shower, washing machine and dishwasher. Moreover, a centralized sewage system is most often absent. Its functions can be performed by a septic tank for giving Tank, in which the accumulation and partial processing of effluents is carried out.

The treatment plant has gained popularity due to its simplicity of design, reliability and affordable cost. Doubt your purchase? We offer you to get acquainted with the device and the principle of operation of the septic tank, its pros and cons, as well as the rules of installation and maintenance.

The above information will help determine the choice of modification of the Tank cleaner, to understand for itself the feasibility of its installation. The material will also be useful to those who already use the storage septic tank in the country.

Device septic tank

Septic Tank is a wastewater treatment plant in which accumulation, sedimentation and partial biological treatment of wastewater takes place. It consists of one to three sections connected in series, the last of which is divided into two chambers.

In the second chamber, there is a biofilter designed for anaerobic wastewater treatment, and a floating load that carries out filtration at the outlet of the tank.

As a result of multi-stage cleaning in the process of overflowing, processing by bacteria and filtration, the degree of purification reaches 78-80%. After exiting the treatment plant, the effluent enters the infiltrator installed on the ground. Here, post-treatment up to 95 - 100% and discharge of the cleaned mass into the underlying soil layers, filtration fields or gutters takes place.

How to install a septic tank for giving Tank
The installation of the septic tank sections, the laying of the supply and discharge communications should be carried out in strict accordance with the manufacturer's recommendations and with reference to the specific geological and hydrogeological situation on the site (+)

At the dachas most often use devices presented in one building.

The design consists of the following elements:

  1. Enclosures, the volume of which is divided into two or three sections by partitions with overflows.
  2. Biofilter with polymer floating loading.
  3. Branch pipes - incoming and outgoing.
  4. One or two necks with tight-fitting lids.

The number of sections in a septic tank depends on its total volume. Two chambers have small volume septic tanks capable of processing up to 600 liters of wastewater per day (execution Tank 1) The rest are divided into three parts.

Options for septic tanks for giving Tank
A sewage treatment system with the Tank logo may include one or more sections, depending on the processing needs

The productivity (daily volume of wastewater) of single-hull septic tanks, depending on the modification, is sufficient for servicing from one to six residents, which corresponds to a wastewater within 1200 l / day.

If it is required to process a larger number of drains, then the working chambers are separate modules, each of which in this case performs its function. Thus the septic tank is arranged Tank 4 - It consists of three tanks connected by overflows.

In addition, by sequentially adding additional containers, it is possible to increase the performance of the cleaning system with any version of the Tank septic tank to the required level.

Elements of a septic tank
All components are made of polymeric materials, not susceptible to corrosion, erosion by water or soil erosion (+)

Features of the device

The case of the device is a monolithic cast capacity made of finned polyethylene, without any seams and joints. Thanks to the rectangular shape, the septic tank is compact and stable, so it is quite simple to mount it even for non-professionals.

In the upper part of the hull, one (Tank-1) or two service hatches are made. The necks are attached to the sealant according to the dad-mom principle.

Ribbed walls, while remaining flexible and resilient at any temperature, increase the rigidity and strength of the structure. With proper installation, they are able to withstand soil pressure even during frost heaving.

The ribbed surface increases the adhesion of the tank with the dense sand-cement pad surrounding it, due to which it is firmly held in the ground and does not float during spring flood. Therefore, the septic tank does not require additional anchoring during installation.

Appearance of the tank septic tank
Monolithic molded polypropylene housing reinforced with stiffeners quietly withstands the damaging effects of the environment - uneven soil pressure, periodic washing with water and temperature changes

The material the tank is made of is a strong polymer compound. It is completely environmentally friendly, biologically pure material.

It does not decompose under the influence of microorganisms, does not react with chemicals, is not susceptible to soil erosion and corrosion. The service life of the polypropylene tank is at least 50 years.

The design and functions of the biofilter

The biofilter in the septic tank is always installed in the last chamber. It is a container in which optimal conditions for growth and reproduction are created. bacteria colonies. To ensure the physical possibility of the settlement of microorganisms, the filter is filled with floating bio-loading.

The main labor force of the biofilter is anaerobic bacteria, colonies of which settle on the walls and bottom of the tanks. Filtration filling is a product, the shape of which allows to create a large area for mechanical cleaning with a minimum size.

The polymer elements of the floating load are lighter than water, so they float and are located at the outlet pipe of the biofilter section. The material of manufacture is chemically stable and absolutely safe for any hydrobionts.

Floating polymer loading
Elements of bio-loading have a different shape - it can be just polymer granules or large shavings (crushed). It is important that they create a free space that can “attach” to itself the maximum amount of pollution

The free surface area is the main indicator of the productivity of biological loading and determines the power of the entire treatment system.

In addition to processing by hydrobionts, centrifugal separation also occurs in the biofilter. The filter capacity itself is made in a form that allows it to work on the principle of a hydrocyclone.

The inlets are located so that the water enters at a certain angle (tangentially) and spins. Due to the vortex microflows, all remaining heavy suspensions are eliminated.

The principle of operation of the installation

Wastewater treatment in a septic tank occurs only mechanically and biologically, without the use of any chemicals. If the structure includes three sections, then the process is accordingly divided into three stages.

Each of the stages takes place in its own working area:

  1. First section is the reception. Through the sewerage from the house, all household sewage flows into it and settles. Here, fermentation and mechanical separation occur - layer-by-layer separation of liquid fractions of different weights. Heavy particles sink to the bottom, lungs (fat, feces, etc.) rise to the surface, and clarified water remains in the middle.
  2. Second section. Liquid from the middle layer of the primary tank enters it through the overflow. Here she continues to wander under the influence of microorganisms and defend - the movement occurs very slowly, without external disturbances. This contributes to the sedimentation of small inclusions that did not have time to precipitate in the previous sedimentation tank.
  3. Third section - biofilter. In its lower part, centrifugal separation and purification of residues of heavy impurities are carried out. A liquid is suitable for the top of the filter, the contamination of which is only biological in nature. When passing through a bio-load, where bacterial colonies are concentrated, organics are purified.

A solid precipitate deposited at the bottom, formed as a result of filtration, separation, and the operation of bacteria, must be periodically removed through the sleeve of a cesspool machine.

Rules for the operation of a septic tank
So that the solid components of the treated effluents settled to the bottom are not pressed or compacted, they must be pumped out at least once a year through a hose connected to the scavenger machine

Colonies of bacteria that live and multiply in the space of biological loading use organics dissolved in water for food. Therefore, recycling occurs naturally. The process produces harmless carbon dioxide, a certain amount of volatile hydrocarbons and water.

For the removal of gases arrange ventilation, which is an indispensable element of the cleaning system.Otherwise, the volatile elements released during fermentation and biodegradation will accumulate in the tank and be discharged through the sewer line into the home space. The building is filled with an unpleasant odor.

Septic tanks - these are sealed containers, the biological treatment of effluents in which is carried out by anaerobic bacteria, without oxygen. These microorganisms are less effective than aerobic (used in volatile systems).

Therefore, the degree of purification of water from organics when leaving the septic tank reaches 75-80%. Drain such a liquid into the ground is prohibited by sanitary standards.

Tank sewage treatment process
The effectiveness of a septic tank depends on the free area of ​​the bio-load and the size of the population of microorganisms. The speed of the fluid in the system also affects the degree of purification - the higher it is, the less clean water leaves the tank (+)

For additional treatment of wastewater after the tank septic tank, a soil dofiltration device must be used. These are structures in which water from a septic tank passes through a layer of rubble or gravel. All remaining contaminants settle in the filtering mound.

Wastewater treatment plant components with septic tank
The composition of the treatment facility based on the Tank septic tank includes one or more infiltrators that perform post-treatment of wastewater and dumping the treated mass into the soil, filtration fields, gutters

Such devices are:

  • infiltrators - industrial tanks without a bottom (reminiscent of an inverted bath);
  • filtration fields - drainage pipe system;
  • filter well - an absorption tank without a bottom with a drainage layer.

The type of construction and the installation scheme of the sewer system is selected depending on the type of soil on the site and the level of groundwater. On this issue, it is best to consult with a specialist.

With proper installation, the septic tank works effectively both in dry weather, and during spring floods and heavy rains. He is not afraid of frosty heaving and seasonal shifts of soil.

Installation of a septic tank in combination with an infiltrator
The simplest and fastest to build scheme. Suitable for soils characterized by normal water absorption - sandy, gravel, pebble

Advantages and disadvantages of the tank septic tank

Non-volatile septic tanks “Tank” are ideally suited for autonomous sewage devices in a private house. It is advisable to equip them in the areas of summer cottages and country houses of seasonal or periodic residence, as well as in areas with frequent power outages.

Tank installation
Installation of the system is not complicated and is often performed independently. This saves an amount equal to the cost of the septic tank itself.

Local communications that do not require electricity to work, are also used in the construction of energy-saving buildings. Technologies that conserve resources are becoming increasingly popular.

Advantages of these septic tanks:

  1. Simplicity and reliability of the design - the tank is practically not subject to wear.
  2. Hull strength - a septic tank withstands the damaging effects of the environment and ensures reliable operation of the system.
  3. Ease of maintenance - lack of components requiring periodic maintenance or repair. All maintenance of the cleaning system based on the septic tank is to call the sewer once a year.
  4. Productivity Opportunity by adding additional modules that can even be connected to a functioning system.
  5. Cleaning efficiency. The sewer system combining the Tank septic tank and the dofiltration device provides complete wastewater treatment from pollution - up to 98%.
  6. Durability - the service life is at least 50 years.
  7. Ease of installation. The compact case of a convenient rectangular shape and low construction weight allow you to install a septic tank on your own, without the involvement of specialists.
  8. Acceptable price - Compared to competitors, the cost of a septic tank is quite acceptable.

Septic Tank - one of the most unpretentious in operation. Allowed to get into the system of toilet paper, food debris and a reasonable amount of household cleaners and detergents.

However, like any engineering design, a septic tank has not only advantages, but also disadvantages:

  • Water leaving the septic tank cannot be drained into the soil according to sanitary standards - a gravel-sand or gravel-sand filter is used to clean it;
  • Installation flaws lead to the appearance of an unpleasant smell in the house coming from the sewer;
  • The sludge accumulated in the tank cannot be used as fertilizer, as it may contain organic residues and harmful substances that can cause contamination of the soil and groundwater.

To prevent odors in the house, a ventilation riser must be built into the supply pipe. Anaerobic bacteria in the processing of effluents emit methane, so gases must be removed. Also, when installing the tank, it must not be warped.

How to organize a septic tank for giving Tank
For the removal of methane associated with the processing of effluents by anaerobic bacteria, ventilation risers are installed. They are installed at the entrance to the cleaning system and at the outlet of the infiltrator (+)

How to increase system efficiency?

Microorganisms are distributed throughout the volume of the septic tank and are concentrated in the bio-load. They enter the system along with drains, and, if there is a sufficient amount of organics, they successfully grow, multiply and eat organic components.

Thanks to bacteria in the septic tank, constant fermentation occurs. Due to this, the separation of organics, mineral suspensions and fat fractions occurs - the liquid exfoliates.

The effluent treatment efficiency depends on the size of the microorganism population. The market has a wide selection of finished preparations containing colonies of bacteria - bioactivators. A popular drug is “Dr. Robik”.

By periodically adding them to the system, home owners improve the quality of cleaning. This is also an effective prevention from problems arising from a decrease in the bacterial population - an unpleasant odor, the formation of thick deposits on the walls, and hardening of sludge.

The activity of anaerobes contributes to the thinning of the bottom sludge and dense crust on the surface, so that the sewage service can be called much less often - once every three years.

Bioactivators for septic tanks
The choice of drugs with bacteria on the market is huge. When choosing, the living conditions of microorganisms must be taken into account. Aerobes that require constant access of oxygen are not suitable for Tank septic tanks - their use can cause an imbalance in the system

When is bioactivator necessary?

For the normal functioning of bacteria, it is necessary that organic matter and a sufficient amount of fluid enter the system. Accordingly, for a constantly functioning septic tank, the use of industrial biological preparations is optional.

However, disturbances in operation lead to the death of the colonies, as evidenced by the appearance of an unpleasant odor. In this case, the bioactivator should be added first. Most often, such a measure is sufficient to restore the normal operation of the cleaning system.

In the following cases, do not wait for the appearance of a smell, since they in any case contribute to a decrease in the population of microorganisms.

It is better to immediately add the finished biological product, which is administered:

  • After a long downtime - for example, at the beginning of the summer season. If preservation was carried out properly, then the bacteria in the septic tank do not die. However, their number is significantly reduced. Bioactivator helps to establish the system in a much shorter time than it will in vivo.
  • After discharge into the sewer chemistry and disinfectants that contribute to the death of aquatic organisms.
  • After freezing fluid in a septic tank. This can happen if the tank is installed without an insulation layer.

A smell from the sewer also appears if a thick layer of fat deposits has accumulated on the walls of the sewer pipes and the walls. Artificially added colonies of bacteria break down and liquefy sediments, after which they freely flow into the sump.

How to apply bioactivator?

A pair of buckets (about 20 liters) of water is poured into the sewer. To biomaterial fell into the septic tank, it is poured or poured into the toilet. After that, they release water two to three times.

The introduction of biomaterial into the treatment system
Before you bring a bacterial drug into the sewer, you should read the manufacturer's instructions

Before use, liquid preparations are simply shaken, but the means in tablets or granules should be applied in accordance with the attached instructions. Some manufacturers recommend dissolving biomaterial in water, others - pour in a dry form.

After the introduction of the bacterial preparation, the water level in the septic tank is controlled for two to three days, adding to it as necessary.

Why do I need filtering?

Anaerobes are not able to process organic compounds completely. They decompose complex compounds into simpler ones, which are contained in the liquid leaving the septic tank.

By draining such water into the ground, you can become the culprit of the infection of it and groundwater. To completely break down simple organics, plums are exposed to aerobic bacteria.

When arranging natural dofiltration, water from a septic tank passes through a layer of rubble or gravel, which is well saturated with oxygen. In such a filtration layer aerobic microorganisms settle, colonies of which, upon receipt of nutrient organics, grow and multiply.

Thus, the last stage of the complete purification of effluents in the sewer system based on the Tank septic tank is carried out.

Which area is not suitable for such a septic tank?

The septic tank itself is absolutely not picky about the soil. The case is strong and tight, the material is not subject to any impact. The design ensures reliable operation, even if the case is constantly in the water.

The presence of a sand-cement pad around the tank protects against uneven extrusion of soil layers during frost heaving.

But there are other essential elements in the cleaning system. Since the prefiltration device requires good absorption of water into the ground, a high level of groundwater can become an obstacle to the installation of such a septic tank. According to building regulations, there should be at least a meter between the filter bottom and the roof of a water-saturated formation.

The septic tank options that are suitable for high groundwater areas are described in here.

The second good reason is poorly absorbing clay soils that do not allow cleaned drains into themselves and below themselves. The filtration layer in such situations is in water and does not fulfill its task: it does not release the system from the purified liquid component.

However, it is possible to use a non-volatile system in such areas. It is only necessary to choose the installation scheme correctly.

For the sewage system with a close location of groundwater for additional purification, infiltrators are used that are installed above a critical level. Between the septic tank and the infiltrator, a storage well with drain pump.

Scheme of installation of a septic tank in a site with a high level of groundwater
A check valve is installed on the nozzle entering the well. It prevents the reverse flow of water if the water level in the well rises above it (+)

If the site is clayey soil, then for the after-treatment of effluents filtration fields. A drainage system is arranged under the main filter layer, water accumulates in the well with the pump and is discharged to the surface in the drainage ditch.

Installation scheme for septic tanks for poorly absorbing soils
The water discharged onto the relief can be used for irrigation, technical and household needs

Installing and starting a new installation to work

Before starting, the septic tank should be approximately 60-70% filled with water. Filling is carried out at the installation stage. Then, over about two weeks, clean water is gradually replaced by effluents. After a sufficient amount of organic substances has accumulated in the tank, bioactivators are introduced into the sewer.

Do not wait for the natural filling of sewage with microflora. This takes up to several months, and at this time the quality of water treatment will be low, an unpleasant odor and various problems can appear. For example, the accumulation of deposits in pipes and on the walls of the tank, which should not be allowed.

Therefore, it is necessary to establish the work of the cleaning system as quickly as possible, which is what ready-made bacterial strains help. Before buying, make sure that the bioactivator is designed for anaerobic septic tanks. Loading aerobes will lead to a long launch.

If you are interested in the installation features of the Tank tank, then we have separate article - We recommend that you familiarize yourself.

Rules for the preservation of a septic tank

If the cleaning system works year-round, then there will be no problems, even if the owners leave the house for a couple of weeks. But if it is planned to stop the flow of wastewater into the septic tank for more than a month, then it is necessary to provide bacteria with food. To do this, make fermented milk feeding into the sewer.

The question preservation of a septic tank for the winter due attention should be paid, since there is live microflora in the reservoir, which must be preserved. For this, it is necessary to take care of sufficient insulation of the structure.

The insulation must be laid on the body when installing the septic tank. If there is no insulation, you can perform it before the onset of cold weather.

Septic tank insulation
It is necessary to insulate a septic tank. Otherwise, the liquid in the tank may freeze and microorganisms will die.

It does not follow:

  1. Pump out drains and flush the chambersotherwise, in the new season will have to restore the bacterial population.
  2. Leave the tank empty. - this guarantees its extrusion from frozen soil and surfacing in spring floods.

For winter, the septic tank is left about 2/3 full. This amount of fluid compensates for the pressure of the soil, and the empty space ensures that the septic tank does not burst even if the contents are completely frozen.

If wells with submersible pumps are mounted in the cleaning system, the units are suspended above the water level for the winter season.

Conclusions and useful video on the topic

A comic video from the manufacturing company quite definitely shows the main components of a cleaning system with a septic tank:

Some stages of septic tank production. Visual measurements of the thickness of the walls of the housing in the context:

Septic Tank is popular in Russia and many CIS countries. It has a simple and universal design. The block-modular cleaning system is able to efficiently serve a small country house, a spacious cottage, and several buildings at once.

If you have experience installing and operating a Tank Septic tank, please share the information with our readers. Leave comments on the article and ask questions on the topic - the contact form is located below.

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Visitors Comments
  1. Good afternoon! What are the requirements for the distance from the septic tank to the foundation of the house, to the trees, to the fence?

    • Expert
      Nikolay Fedorenko

      Good afternoon, Olga. As such, there are no strict requirements for the installation distance to the septic tank. Here are the highlights:

      1. SNiP recommends installing a septic tank at a distance of at least three meters from the foundation.

      2. Different types of trees have different root systems. Damage to the septic tank is unlikely, but the fibrous system is quite capable. The safety distance is determined by the fact. It can be from 2 to 4 meters.

      3. The septic tank is recommended to be installed along the border of the site from the carriageway at a distance of at least 5 meters from the road - in the future this will facilitate maintenance and repair of breakdowns. The distance to the fence of the neighboring plot is at least 3 meters.