Septic tanks including septic tank company bethany are the oldest facilities used to anaerobically treat domestic sewage and sediment to date. They are used for local treatment of domestic and industrial wastewater in areas where there is no central sewage system or certain requirements for discharged water are regulated. No matter the shape, specific construction and materials used septic tanks are usually built in small sites, such as single-family homes and high-water eating establishments.
Construction and principle of operation
The septic tank is a sediment in which the wastewater flows through the gravity principle. The facility is constructed underground and is hermetically sealed, as far as possible according to its specific construction, but is provided with cleaning and ventilation openings. It consists of one, two or three cameras (tanks) and contaminated water passes through. When designing a septic tank, it is important to take into account the filtering ability of the soil and to assess the highest level of groundwater to avoid drainage into the sediment. In case, that the terrain is sloping, the absorption field must be maintained in certain facets, in order to prevent the wastewater from the surface in the lower part of the field.
The waste enters the sedimentary part of the septic tank, where it is gradually separated into two fractions. In this process, heavy parts descend to the bottom while light suspensions (oils, a mixture of fat and water) enter the second compartment is the mass of heavy suspensions. After a while, secondary decomposition begins, under the influence of the bacteria present in the waste. The wastewater remains in the septic tanks for no more than three days, with the anaerobic digestion of the dissolved and colloidal substances in the stream incomplete – only in the first phase, called acidic decay. Purification efficiency in this compartment is no more than 60 “/ o.
In the second compartment again all the processes described above are carried out again, except that the contaminated water is distributed evenly over the filter field. There are also bacteria that contribute to the final decomposition of the remaining impurities.
The septic tank purifies from 20 to 50 cubic meters of wastewater per day, absorbing about 90% of the pollutant content of the water already used. It is important to clarify that septic tanks are not facilities for the final treatment of water and even though it is water appearing clean and clear from them, it is necessary to go through natural soil filtration or other methods of final purification. This method is called biological treatment and is carried out at a distance of 100 -200 meters from the facility in the direction of groundwater flow.
Legality of the septic tank
The construction of this type of equipment must be carried out in accordance with the regulated hygiene and sanitary requirements, which are regulated in the Territorial Planning Act. They are classified in several directions in terms of volume, location and construction of the septic tank.