Reconstruction of sludge drying beds of waste water treatment facilities in the city of Novoaltaysk

The research target is the waste water treatment facilities of the City of Novoaltaysk, the Altai Region. The sludge formed at treatment facilities is represented by suspended solids of wastewater settled in primary settlers and surplus activated sludge. The sludge mixture is removed from the primary settlers with a centrifugal pump SD-212/8 (capacity of 200 m3 h) 3 times a day for 25 minutes. The removal of the mixture by a centrifugal pump leads to liquefaction of the sludge to a concentration of 30 kg m3 (moisture content of 99.7%). The amount of mixture pumped out from the primary settlers makes 750 m3 day. Then the mixture of surplus activated sludge and fresh sludge is fed for drying to sludge drying beds with earth foundation without draining (there are 10 sludge detention ponds of the size of 100 × 100 m each). The sludge beds occupy about 10 ha of the territory. If the centrifugal pump for pumping sludge from the primary settlers is replaced with a plunger pump, the moisture content of the pumped sludge will make 97% (the concentration of 30 kg m3); the amount of sludge will decrease 10 times. This will reduce by the same factor the area of sludge beds used for sludge drying.