Wastewater enters the preaerator-biocoagulator, where it is saturated with air and flocculant is dosed. Then, the wastewater flows by gravity into the first-stage bioreactor and the second-stage bioreactor, where the biological treatment process takes place using free-floating microflora. After the second-stage bioreactor, the wastewater flows by gravity into the secondary settling tank, where phase separation occurs.

In the biofilters of the first and second stages, proteins, fats, carbohydrates, surfactants (surfactants), ammonia and amino compounds are destroyed and absorbed by bacteria, algae, protozoa, which are both in a free-floating state (bioreactors of the first and second stages, secondary settling tank) and in an immobilized state (biofilters of the first and second stages). A significant amount of contaminants settles as a result of flocculation of microbial metabolism products.

The returned activated sludge from the secondary clarifier is fed via airlift into the first-stage bioreactors to improve the wastewater treatment process, and the excess is fed into the aerobic sludge stabilizer.

Stage I and II biofilters are periodically washed to remove excess biofilm. From the stage II biofilter, wastewater is fed to the disinfection unit.