Sewerage Treatment Plant

Operation of the System and Processing of Sewage

Liquid effluent (sewage) from any building passes through the private system (without or after pre-processing needed for industrial sewage) to the central manhole of the building and from there to the public sewer located in the street.

Sewage, through public sewers/pipes with natural flow, end to the main collectors where it is piped to the Sewerage Treatment plant.

Today, there are three central pumping stations that assure the propelling of the sewage to the treatment plant, where it is fully processed (third grade).

1. The first stage is the removal of large foreign particles with the use of mechanical grates.

2. Next follows the removal of the thinner solids (soil, sand, stones etc.)

3. The first sedimentation is carried out in tanks from which the first organic solids are removed. Thus the organic load is reduced by 30-40%.

4. The sewage then enters the aeration tanks where, by biological methods, the remaining organic load is reduced up to 90%.

5. Then the second sedimentation is carried out where the processed water is separated from the active mass and propelled to the third-grade unit where the natural filtration through layers of sand and fumigation are completed.

After the above processing, the resulting water is ready for irrigation in agriculture.
The biological sludge produced as a result of the processing is dried after passing through a process of digestion and concentration. The dried mud is a good fertilizer, containing many nutrients and can replace commercial fertilizers.