Ways of clearing and bezzarazhivanija sewage

Clearing of household sewage can be divided into two stages: mechanical (clearing of the large mineral and small organic weighed substances) and biological clearing (a mineralization of the organic substances which are in kolloidnom and the dissolved condition) which is carried out as a result of microflora ability to live.

Mechanical sewage treatment is spent by means of lattices, peskolovok, sediment bowls.

The Lattice represents the parallel iron rods established under a corner 70 В° in pipelines on a course of a current of water. Gleams between rods can be various, is more often they make 16-30 mm. On lattices the large weighed substances which sizes exceed width of gleams between rods (a paper, rags, cotton wool, kitchen garbage) are late. The late garbage leaves manually by means of a rake or mechanically.

Peskolovka represents the tank with two-three sections, each of which can work independently, intends for detention of heavy mineral impurity. The action principle is based on change of speed of movement of a stream of water so that to promote subsidence of heavy sand and to interfere with subsidence of an easy organic suspension. Usually speed from 15 to 30 is given to sewage Time of passage of water through peskolovku not less than 30 see/with with. A bottom peskolovki sometimes drenirujut to dehydrate a deposit and to facilitate that its removal and drying.

The Collected garbage from lattices and peskolovok stores in the closed receivers under a layer chloric to exhaust. Then them burn or take out on sewage disposal fields.

After lattices and peskolovok sewage arrives in sediment bowls where the great bulk of the weighed substances settles, basically an organic origin. Sediment bowls represent tanks in which garbage in the form of a deposit drops out on a bottom at the expense of reduction of speed of movement of water. Sediment bowls happen horizontal, vertical and radial.

Depth of a horizontal sediment bowl makes 1,5 2 m, speed of movement of sewage - 7 mm/with, in a vertical sediment bowl - 0,7 mm/with. Time of stay of water in the specified sediment bowls - 1,5 ch.

To avoid deposit rotting in sediment bowls, removal it make daily. Delete a deposit on a pipe located at the bottom of a sediment bowl, the pump or under the pressure of laying above a liquid column. This deposit is called as silt. Further silt arrives in metantenki for neutralisation.

Radial sediment bowls are superficial round tanks with a uniform bias of a bottom to the centre. Their diameter is made from 16 to 40 m. by Water moves in a sediment bowl on the central pipe from below, with decreasing speed moves to periphery and merges in an external circular trench through apertures in boards. The dropped out deposit is raked up to the sediment bowl centre in the profound receiver and leaves under the pressure of a water column or the pump. Speed of movement of water - 7 mm/with. Time of stay of water in a sediment bowl - 1,5 ch.

Silt Formed after upholding or a deposit arrives in metantenki - cylindrical or rectangular rezurvuary with the conic bottom which is coming to an end ilovoj with a pipe. Silt arrives from above on a pipe. In metantenke it is exposed to alkaline fermentation with formation in the subsequent new silt of black colour with a specific smell. To improve deposit processing, it is warmed up and mixes up by means of steam or water. At fermentation gas which gathers in the gas cap located in the top part metantenka is formed. The silt received after fermentation is exposed to mechanical dehydration and is unloaded on ilovye platforms where quickly dries up.

Biological clearing is necessary for a mineralization of the dissolved organic substances which cannot be taken mechanical by. Distinguish biological sewage treatment natural and artificial. Biological sewage treatment in natural conditions is carried out on irrigation fields, fields of a filtration and biological ponds. Sewage treatment in artificial conditions occurs in special constructions in which the conditions which are taking place or in soil (biological filters) are reproduced, or in a reservoir (aerotenki).

Filtration Fields represent the ground areas divided into separate cards. Cards are protected by earthen shaft or have furrows and beds of type of the garden. Sewage on pipes moves to the highest point of fields of a filtration, and therefrom samotekom arrives in a special network of distributive channels on separate cards. Depending on the device of a site-card the irrigation is conducted or a continuous gulf, or on furrows. After that in the top layer of earth of 40 sm begin thickness processes of biochemical oxidation of organic substances of sewage. There is it so: sewage, being filtered through soil, leaves in it the weighed substances which through certain time form a film in a time of soil. This film detains the organic substances dissolved in sewage which are oxidised the oxygen getting during a time of soil from air. As a result there is a mineralization of organic substances. Here there is a delay bolshego quantities of microorganisms, and also eggs gelmintov.

The Filtered water gathers by means of a drainage network of the open or closed type. An open drainage arrange in the form of the ditches passing on perimetre of sites and having a bias towards the main drainage ditch, deducing the cleared water in a reservoir. At the closed drainage on each site on depth of 0,75 1 m pawn drainage clay pipes with prozorami between them for receipt of drainage water. These pipes are connected to a taking away main drainage collector.

Irrigation Fields are intended for sewage treatment with their simultaneous use for the agricultural purposes. The water, passed mechanical clearing here arrives. Irrigation fields the same as filtration fields are arranged. On irrigation fields grow up agricultural crops (technical, grain, fodder).

Biological ponds are applied for doochi-stki waters after artificial biological clearing and can work only during the warm period of year.

Biofilters represent the tanks filled with a firm lumpy material (slag, rubble, gravel) through which sewage is filtered. Biofilters arrange on platforms with the impenetrable basis on which place drainage pipes for water gathering. Lateral walls for the best air permeability have cellular structure. On a drainage bottom fill a loading material in a following order: from below a layer of large gravel or slag, then less large and from above a layer of small gravel.

The Sewage, passed mechanical clearing, from a dosing out tank moves in the distributive network of the biofilter located in its top part, and by means of sprinklers, being sprayed, arrives in a loading material of the biofilter. Here there are same processes, as in soil (filtration fields see). After a while on the top layer of the biofilter (5-10 sm) the biological film detaining organic substances, which under the influence of air oxygen mineralizujutsja is formed. To provide the best access of air, an irrigation of a surface of the biofilter make with intervals 3-5 minutes Process of oxidation of organic substances occurs on depth to 50 microorganisms-devourers Thus available in a film (an infusorian, zhgutikovye see, etc.) release water from microorganisms, including the pathogenic.

The Aerofilter is more effective soruzhe-niem, than the biofilter, and differs from it that has the big height of a filter-bed (3-4 and the device for filter ventilation.

Sewage moves from above, and air is forced from below towards to a filtered liquid. Such enrichment by oxygen in 2-3 times accelerates oxidation process that allows to pass great volume of water in comparison with the biofilter.

aerotenk represents the long ferro-concrete tank depth of 3-6 m without a loading material. Oxidation of organic substances here occurs in the liquid environment. Through such tank sewage in which add active silt slowly proceeds. It represents the flakes plentifully occupied by microorganisms-mineralizatorami which star in oxidation of organic substances. In aerotenk with the help vozduhoduvok air which arrives through filtrosnye plates (porous), located in the bottom part of the tank is forced. After passage aerotenka sewage goes to a secondary sediment bowl for removal of active silt which goes again in aerotenk.