Septic tanks are used as pre-treatment units before the sewage enters the municipal sewage network or absorptive wells. The septic tanks can be used with simple or advanced systems depending on the quality of the wastewater requested. In most applications, simple septic tanks with at least one separating wall inside are used.
In this septic tanks the inlet sewage settles in the first section and anaerobic bacteria break down most of the accumulated sludge. Also some of the floating materials remain in the first section and on the surface of the sewage. Wastewater then enters the second section, where secondary settling occurs, the semi-treated wastewater is then discharged from the septic tank.
A vent pipe is used to remove the gases. Usually a separate visit is considered for each septic tank section.
Wastewater treatment is performed by a polyethylene septic tank with a separating wall, which increases the number of separating walls if further treatment is needed. Aeration systems can also be used to create an aerobic treatment system. The use of septic tanks is currently increasing rapidly. Due to the increasing expansion of purification systems, the use of simple and advanced septic tanks is increasing. A significant percentage of wastewater is treated in a septic tank. The volume of sewage entering the city network is reduced. Septic tanks are sometimes used in conjunction with degreasers in the treatment system. Polyethylene septic tank also has special advantages due to the material of polyethylene. Septic tanks are used in most industries and even home applications around the world.
In some projects, wet-land is used in addition to septic tanks. These sand filters improve the quality of the filtration operation. These filters can also be multi-stage.