In rural areas, there is no possibility of connecting to a centralized sewage system, therefore, VOCs - local treatment systems are arranged in suburban buildings to drain contaminated wastewater. Most often, septic tanks are used for these purposes.
Definition and purpose of septic tanks
Cesspools - the most primitive and cheapest waste disposal, but not hygienic. At the bottom of the dug hole, a base is made of concrete or brick. The walls of the structure are isolated from leaks, and its contents are periodically pumped out. There is a persistent unpleasant aroma that spreads over the site. The distance from the drain pit to the residential building should be 10-12 m according to SNiP.
Septic tanks with ground filtration have become widespread. Several sealed containers are buried in the ground. Barrels are mounted in such a way that water flows from one vessel to another. Particles of different sizes settle to the bottom of each of them. From the last tank, water flows through drainage pipes to the filtration field, which is arranged from crushed stone and sand. There is a natural purification of water that seeps into the soil.
Filtration fields prevent the terrain from becoming a swamp. But they require care. With a frequency of once every 3-5 years, the drainage layers are removed and re-filled. Buried containers are also clogged with sediment, so they need to be cleaned 1-2 times a year.
IN biological treatment plants there is an aerobic clarification of wastewater. It is a progressive wastewater disposal method used in the urban system.
For an individual building or a system of cottages, stations with equipment of lower productivity are used. These are containers in the form of rectangular cubes with a side size of 1 m and a depth of 2-3 m. They are buried in the ground. Additionally, several compressors are built in, which bubble the waste water with air bubbles for better mixing with the activated sludge, so that microbes that eat food debris and fat deposits can develop.
All wastewater content is recycled into non-hazardous sludge. It should be scooped up and used as a green plant fertilizer. The outlet water is purified up to 98%. You should not drink it, but you can water the garden and vegetable garden.
SBO have certificates from the environmental safety supervision system. Their device is cost-effective and affordable for rural residents. Unlike septic tanks, treatment plants require a power supply system to connect the compressors. The power of the station is small, the consumption is comparable to a 100 W light bulb, but if the electricity is turned off for 1-2 days, the beneficial bacteria living in the activated sludge die.
Device and principle of operation
Septic tanks of a storage type work as a modified cesspool, where all the drains from the house and the adjacent area are drained. Heavy particles settle to the bottom of the sump, lighter suspension and fatty inclusions remain on the surface.
Unlike a cesspool, septic tanks have a sealed device. Technique is used to remove deposits in them. If the amount of wastewater is small, for example, in a summer cottage, storage tanks justify their purpose, the simplicity of their arrangement satisfies consumers. It is necessary to monitor the water level in order to pump out in time.
Overflow septic tanks are purchased for cottages in which people constantly live. They also need cleaning, but much less frequently. They work on the principle of cascade liquid transfusion:
- Chamber No. 1 is designed for settling heavy waste.
- Waste from the first container cleared of large inclusions is poured into chamber No. 2. This is a workplace for aerobic bacteria, which decompose organic residues in the course of their life. The degree of purification is 60%.
At the third stage, the water purified from organic matter enters the filtration fields, where it is naturally purified through the drainage fill.
Types of septic tanks
- productivity;
- the principle of work;
- reliability of cleaning.
Storage tanks are made of plastic, metal, brick or reinforced concrete. They can be horizontal and vertical, surface or underground. To select VOCs, the volume of wastewater is determined, which depends on the number of people living, the connection of washing machines and dishwashers, sinks, bathtubs, shower stalls.
Metal barrels for septic tanks rust from time to time, so their choice is not a good option.
For private estates, where they live permanently, it is preferable to stay on VOCs with soil filtration or bioremediation. For the construction of the reservoir, reinforced concrete rings are used, which are cheap and durable.
Installation features
Arrangement of a brick installation occurs according to the following algorithm:
- the soil is taken out under the established parameters of the septic tank;
- the foundation is poured;
- brick walls are laid out;
- for waterproofing, walls are rubbed on both sides;
- an additional layer of mastic is applied outside.
The design of the device does not require a call of technology, building materials are available for free sale.
Advantages and disadvantages of septic tanks
Accumulation tanks have the simplest design, but with an increase in wastewater, the cost of sewer services increases.
Pros of using overflow VOCs:
- uncomplicated cleaning method;
- simple operational maintenance;
- drains are treated to the point of being discharged into the ground or natural water body;
- reducing the cost of calling for sewage disposal equipment;
- work even in conditions close to the surface of soil waters.
The disadvantage of this device is the impossibility of using them for additional purification of water in clayey areas, as this will lead to the formation of puddles.
Biological treatment plants can be installed in areas even with heavy soils. They provide high purification of effluents, making them safe for subsequent use in economic purposes. It takes 2 days to establish the work of a septic tank, but in subsequent operation, constant monitoring is not required. Sludge is removed once every 5 years.
The high cost is the main disadvantage of the SBO. Another disadvantage is the need for power supply, since efficiency decreases during power outages.
Septic tanks prices
When choosing a storage septic tank, preference should be given to containers with a large volume and strong walls that do not deform under soil pressure, as this can lead to leaks.
The price of a plastic container for a septic tank is 13 thousand rubles.
Septic Tank Unilos, providing deep biological wastewater treatment up to 98%, made of polypropylene, costs 76 thousand rubles. The material is resistant to sunlight, low temperatures and mechanical stress. The device is adapted to the climatic conditions of Russia. The manufacturer's warranty is 2 years.
The septic tank Alta Ground Master 22 is designed for a group of cottages. The device has a 60-year service life. There are no restrictions on the discharge of household waste. Does not require power supply. The cost is 529 thousand rubles.
Septic tank Topas 6 LONG is designed for 6 people, its capacity is 1000 liters per day. Manufacturer's warranty - 3 years. Tank dimensions 1.2 * 1 * 3.1. Electricity consumption 1.5 kW daily. The cost of the product is 123 thousand rubles.
