99
2. General
4. Sedimentation phase
The treatment phase is followed by a 2-
hour sedimentation phase. Any solids con-
tained in the sewage as well as the activa-
ted sludge settle on the bottom of the tank
and a clear water layer thus forms in the
upper area, while a sludge layer made up of
microorganisms forms on the bottom.
5. Extracting the clear water
(clear water extraction)
Clear water now remains above this sludge
layer and is fed via the air syphon for the
clear water extraction into the preclarifier or
infiltration plant.
6. Repumping the activated sludge
(sludge extraction)
Excess activated sludge is pumped back
into the preliminary sedimentation.
Inno-Clean_2. Generation_3-sprachig_132Seiten:010-341 Stand 05/07 26.11.2009 12:43 Uhr Seite 99
