Sewage treatment plants (KOS) are designed for treatment of domestic waste water and water with similar composition to the standards corresponding for discharging into fishery ponds.
Treatment plants provide a high degree of purification without large construction and production costs.
Structures are compact, reliable, and easy to use.
The typical process scheme includes: averaging, mechanical treatment, biological treatment, sludge separation stage, post-treatment, and disinfection.
The sludge generated during operation is mechanically dewatered and then disposed of in a solid waste landfill.
Mechanical or manual grids, sand traps, or combined mechanical treatment plants that combine the functions of grids and sand traps are used as mechanical treatment facilities.
Advantages of combined units:
- high cleaning degree from coarse inclusions and sand,
- automated unloading of detained waste into containers for subsequent removal.
Operating principle of KOS
Biological treatment of wastewater is carried out in aeration tanks with denitrification and nitrification zones or biofilters with polymer and crushed stone loading.
If necessary, aeration tanks are equipped with polymer loading blocks to intensify the process of biological treatment. This creates a free-floating active sludge or attached biofilm in the aeration tank.
Aeration tanks are equipped with aeration system necessary for the vitality of active sludge and large-bubble barbotage system, which allows timely removal of excess biofilm, thus maintaining optimal concentrations of biofilm and active sludge.
Biofilters are also used as biological wastewater treatment facilities. Biofilters use a periodic supply of wastewater using sprinkler systems. Biofilters are used with both polymer and gravel loading.
Secondary settling tanks or membrane bioreactors (MBR) are used for sludge separation after the biological treatment plant.
The purification process in secondary sedimentation tanks is based on the precipitation of active sludge or biofilm under the action of gravitational forces. Sludge is separated in the MDR by passing the sludge mixture through membrane modules that allow retention of active sludge.
After the sludge separation facilities, the process scheme also includes post-treatment facilities.
Wastewater post-treatment is necessary to bring treated wastewater to indicators that allow it to be discharged into fishery water bodies.
Sand or charcoal filters are mainly used to retain residual contaminants. The filters perform automatic rinsing to keep the filters clean and achieve a high cleaning effect.
The last stage of wastewater treatment before discharge into the outdoor network is disinfection.
UV disinfection units of ODB type are used for the disinfection stage.
Excess active sludge is dewatered at mechanical dewatering units (bag, auger, press filter).
Advantages of KOS designed by Bunter Group
- high cleaning effect achieved by developing individual designs and moving away from typical sewage treatment plants;
- full readiness of the equipment and minimization of works on the construction site;
- high qualification level of all specialists;
- high quality of construction and installation works;
- short design and production terms.
There is no standard KOS line as the perfect quality of treatment can be only achieved by adapting to the specific customer’s requirements. Each wastewater treatment plant is calculated, designed, and manufactured according to individual projects.
The composition of sewage treatment plants is selected based on the quality of the initial effluent.
KOS are manufactured for any capacity within the range of 5-5000 m3/day and may consist of one or more modules or a pre-fabricated building.