Customer: School
Year: 2019

Boarding School in South Africa

Regarding that most schools are on a tight budget it is important for their wastewater treatment plant to be cost efficient.

Even though this particular school has permanent residents and therefore also operates during holidays it is important to have a SBR system that adapts to the different periods of high and low wastewater for highest efficiency. (for lowest expenses)

Clearfox SBR plant works as an activated sludge treatment plant.

The treatment plant has an upstream coarse separator that serves as storage for the primary and secondary sludge and to buffer the inlet. Sludge filling and clearwater extraction are effected by means of airlift pumps. The plant’s control system recognises four main states in the normal cycle.

Sequential Batch Reactor (SBR) process:

1 (Filling phase): where the sewage enters the first chamber and any large solids are retained. The wastewater then feeds into the second chamber which is the biological reactor.

2 (Cleaning/Aeration phase): where actual biological treatment by microorganisms starts to occur in the reactor. Short aeration and rest [non-aeration] phases alternate in an under control cleaning process. An activated sludge develops with millions of microorganisms which break down the wastewater completely.

3 (Sedimentation phase): where a rest phase follows. The live or activated sludge sinks to the bottom of the water column. This allows a clarified water zone to form at the top of the reactor chamber.

4 (Clearwater Removal phase): where purified wastewater at the top of the water column now discharges from the system. The settled activated sludge transfers back into the first chamber and the process repeats with the next batch of wastewater.

Energy-saving cycle (optional – level switch required)

The purification programme continues running unabated, however with a shortened aeration phase, which reduces the amount of energy required. Depending on the inlet quantity to the pre-chamber, the programme decides fully automatically whether the energy-saving cycle should continue or whether it should switch back to normal mode.

Sketch of the project:

Advantages of the ClearFox SBR system:

  • Very low energy consumption with energy-save mode
  • Quick and easy to install
  • Automatic operation and only minimal maintenance required
  • Very small eco footprint
  • Low purchase price
  • No moving parts in the tank
  • Entire process powered by a small air compressor (60 watt)
  • 30% less sludge production than competitor systems
  • Odor free and whisper quiet operation
one chamber sbr