For the service and inspection of the aeration system, the activated sludge basins are emptied every two years.
Sonnek Engineering GmbH (Tsurumi partner)
Abwasserverband oberes Drautal-Weissensee
Pumping of activated sludge in a community sewage treatment plant. Basin depth: 6m.
For the service and inspection of the ventilation system, the activated sludge tanks are emptied every two years.
The activated sludge has a dry substance content of 1.5 to 2%.
During emptying of the basin, the circulation and mixing of the sludge is turned off, and the sludge forms a sediment on the bottom. Pumping time 2 days.
In the floor of the basin there is a 100mm deep sump, meaning that when the basin is emptied the sludge remains lying on the bottom. It must be removed.
Use of a Tsurumi model KRS2-80 pump with an agitator. This pump was leased from the Tsurumi inventory for the purpose.
The pump is submerged by only 100-200 mm, running in snore mode, and the sludge is manually transported to the pump with scrapers and pumped away. Pumping time 1 day.
The bottom sludge has about 3-5% dry substance.
The basin could not be emptied with the standard wastewater pump available, since its motor had no cooling and underwent thermal shutdown.