The Sequential Batch Reactor (SBR) is one of the oldest forms of sewage treatment.
It is also one of the first designs that Eflo made dating back to the 1970s !
Eflo originally called their process the "Filandraw" and were awarded a patent
for their novel decanter design and improved "continuous" process.
Now it is referred to as the EfloSBR and is available for capacities from 10 - 50,000 m3 per day.
Either as prefabricated package plants for the smaller sizes or using concrete tanks for the larger plants.
The simplicity of the plant is its winning feature, despite the footprint being much larger than the MBR or SAF processes.
The complication arises in the control programme to ensure all of the sequences,
that all happen in a single tank, do so at the correct time. These sequences are Filling,
Aeration, Settlement and Effluent Discharge.
In 2010 Eflo improved their decanter and now offer a new type of, multi-weir,
hydro-pneumatic decanter which is permanently submerged thus eliminating complex weir lifting motor/gearbox units.
The effluent decanter is the single most challenging design aspect in an SBR plant.
This is because it needs to discharge a very large volume of water over a very short time
to allow for sufficient periods for aeration and settlement. The decanter employs a collection weir and a scum baffle.
The design of the decanter must ensure the weir loading is within proper, engineering design limits
and this means they need to be very long.
The EfloSBR is a good product to retro fit into existing tanks as in the photo below where is helped increase treatment capacity.