A secondary sedimentation tank allows the microorganisms and solid waste to settle out.

Clarifiers: The final stage of the activated sludge process is the secondary sedimentation tanks (called clarifiers).

While the effluent SS increased at the lower HRTs of 3.5 and 2.5 h, the system still operated effectively without a secondary sedimentation tank.

Like the previous extensions, these facilities carried their stage number e.g. primary sedimentation tanks 4 and secondary sedimentation tanks 4 (trickling filter 4 however, was deferred to a later date).

Aeration is needed to lift and mix the sludge, to add oxygen into the sludge for the micro-organisms and to continue the process of denitrification.The sludge must be kept in suspension until it reaches the secondary sedimentation tanks.

Complete systems available for Primary and Secondary Sedimentation tanks, DAF tanks, surface skimmers, Grid collectors, Grit Bucket Elevators, Lamella Tanks and API separators.

In day-to-day operation the ASR (and secondary clarifier) are used in parallel with the trickling filters (and secondary sedimentation tanks) with the principal objective of reducing the organic load on the oxidation ponds.

Tuke and Bell offer a complete range of rotary scrapers for primary and secondary settling tanks, for sewage works and water treatment plants.

Secondary Settling Tanks - The force of the flow slows down as sewage enters these tanks, allowing the microorganisms to settle to the bottom.

Settling tank (usually referred to as "final clarifier" or "secondary settling tank") to allow the biological flocs (the sludge blanket) to settle, thus separating the biological sludge from the clear treated water.

Its like a race track, sludge goes from the anoxic tank to the aeration tank around to the secondary settling tanks (clarifiers) where the sludge settles and is pumped back to the start of the anoxic tank, and starts all over again.