HYBACS® is our core technology for domestic (municipal) and industrial biological wastewater treatment. We supply the HYBACS® technology in South Africa via an exclusive licence agreement with Bluewater Bio

Activated Sludge Process at Reduced Cost, Energy & Footprint

HYBACS® is a patented HYBrid ACtivated Sludge process. The core benefit of HYBACS® is that it enables an existing activated sludge process to be swiftly upgraded for increased capacity or performance, by simple offline installation of SMART™ units.


  • Proven technology internationally
  • Enables an existing activated sludge plant to treat double the flow and load
  • Construction is off-line, so no interruption to the process
  • Modular construction enables rapid deployment and minimum footprint
  • HYBACS® sludge is highly settleable
  • Reduces power consumption associated with aeration by up to 30%
  • Effective for nitrogen and phosphorus removal
  • Low capex, opex and whole life costs
  • Simple operation and maintenance
  • Low embodied & operational carbon
  • Intrinsically odourless
  • Full local support
The bottleneck in the conventional activated sludge process is the hydrolysis (breakdown) of nutrients into molecules which are small enough to pass through the bacterial cell wall. HYBACS® overcomes this bottleneck using a unique attached-growth reactor, called a SMART™ unit, in which the conditions cause naturally-occurring bacteria to over-produce hydrolytic enzymes. The SMART unit can be seen as a hydrolysis reactor.
Hydrolysed material is absorbed by bacteria and carried into the activated sludge process downstream, where conventional oxidation and nutrient removal takes place. However, since the hydrolysis bottleneck has been overcome, the activated sludge stage can operate at a much higher loading rate. Hence more flow and load can be treated within an existing activated sludge process, and tighter discharge standards can be achieved without the need for additional tank capacity.
A secondary benefit of pre-hydrolysis in the SMART unit is that the high floc loading helps nutrients to diffuse into the centre of sludge flocs. This promotes the growth of large, dense flocs with excellent settlement characteristics. Thus a HYBACS® upgrade enables both the aeration tank and the clarifier to accept a higher load.



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