Sequential Batch Reactor
An addition to the existing technologies to the market is the SBR - Sequential Batch Reactor. This technology was developed mainly in Australia and US with Fill and Draw concept.
The SBR basically has a single tank known as the SBR tank where four main process of STP takes place, viz
Filling: This stage is where the Sewage is filled into the SBR tank.
Aeration: As any STP the aeration takes place in the SBR tank for programmed time frame to provide the required air.
Settling: The Settling stage is where the reacted water is allowed to settle with no aeration or pump operation. Here the solids settle to the bottom of the tank and the clear water remains at the top.
Decanting: The clear water from the top is decanted into the next tank by use of decanter mechanism which may be through decanted specially designed mechanism/Pumps making sure no sludge slows to the next tank. The Sludge at the bottom remains in the SBR tank for next batch providing the necessary microorganisms.
SBR's are designed for automation and it can be used where the load of sewage keeps varying lot.