Cleaning any waste water is very important, but this work has always been a difficult thing. And when the usual stations for biological water purification in industries ceased to cope with such an important task, biological waste water treatment plants, characterized by high complexity and efficiency, came to the fore. Also, the problem of cleaning sewage from sewerage of private houses is considered to be more and more acute, since it is unprofitable to lay sewage pipes that are many kilometers long, and also environmentally unsafe.
The biological method of water purification is being reduced to the use of microorganisms, which are able to perform the splitting of substances of organic origin into simpler elements (carbon dioxide and water). The principle of the biological method of wastewater treatment is the use of aerobic (requiring oxygen for vital activity) and anaerobic (oxygen-free) bacteria. Wastewater treatment by biological method presupposes an oxidative process.
Nowadays, there are special complexes that make it possible to perfectly clean sewage pipes from harmful impurities. Such devices can be used as a local treatment facility for the entire settlement or a detached house. Aggregates with compact dimensions are designed for mechanical cleaning and comprehensive biological water purification.
If you take into account the method of purification and design features, such settings are of three types:
Aerotank performs a complete biological treatment of sewage of any nature. It is a polypropylene reservoir in the form of a cylinder or a rectangular parallelepiped. He has inside partitions, creating compartments in the amount of three pieces. The first is used as a primary settler, the second acts as an activator, and the third is a secondary settler.
In the first compartment there is a mechanical purification of effluents from insoluble impurities and accumulation of excess sludge. The second compartment, which is an activator, is represented by two chambers, which are called a nitrifying and denitrifying agent. In the first chamber, mixtures of ammonium salts and substances of organic origin are oxidized. In the second chamber (in the anaxic zone), the process of removing nitric acid salts formed during nitrification is carried out. A secondary settler is used to separate the recycled liquid from the sludge.
At the top of the unit there is a cover, which is equipped with special hatches that allow the unit to be serviced, to track all processing processes and to draw water after biological treatment of sewage for sampling. In the aeration tank, an air compressor is used, which deals with supplying compressed air. The compressor can be located either in the housing of the unit or in a separate room. It is possible to mount a system for the biological method of wastewater treatment with the following options: ground, semi-deep, underground.
The drains first enter the first settling compartment, designed to trap floating impurities and heavy insoluble elements. Water, after cleansing by mechanical means, enters the activator, and then it is purged with air supplied from the air compressor. Then the water is sprayed, for which the bottom aerators are used, which have a rubber membrane. Separation of silt and water follows after the activated mixture flows through the sedative zone located in the secondary settling tank. The purged liquid is then discharged through the top of this compartment.
From the settling compartments, the activated sludge is advancing into the denitrifying agent. With the simultaneous introduction of effluents and the return of activated sludge, effective removal of contaminants is obtained. The resulting excess sludge is transported to the primary settler in periods, and after large quantities are accumulated there, it is utilized, for which a sewage machine is used.
The aerobic process of the biological method of wastewater treatment is that natural bacteria are used that multiply and live under certain conditions, which is used to purify the drains. Due to the fact that biological purification of water and artificial injection of air used for the oxidation of sewage substances are combined, biological processing is accelerated several times and water treatment is improved. Bacteria have a destructive effect on substances of organic origin, using them as food. As a result of the development of microorganisms and the aeration process, substances of an organic nature are oxidized and decomposed into harmless elements (the efficiency of water purification in this case is up to 98%). Used for the purification of waste water, similar equipment that can be installed near residential buildings, pleases with the absence of an unpleasant smell. The resulting purified water is drained to the ground or discarded in water after disinfection.