The FlexZone Adaptive Process Volume System is a flexible activated sludge treatment solution that is designed to address diurnal and seasonal loading conditions while accommodating current and future water quality requirements with an emphasis on optimizing energy efficiency and process control. The FlexZone system provides a high level of operational flexibility and efficiency throughout the life of the treatment facility.

To learn more about the FlexZone system, watch this educational webinar.

view brochure

How It Works

Eliminating physical barriers, the FlexZone system dynamically matches anoxic, low dissolved oxygen (DO), and aerobic volumes to changing influent conditions. Air delivery to satisfy oxygen demand is provided by diffused aeration and process blowers. BioMix Compressed Gas Mixing operates independently or as part of SyncroMix (concurrent operation of BioMix and aeration) to provide ideal mixing. Instrumentation provides real-time feedback of process conditions. The control system automatically adapts aeration and mixing settings based on instrument readings and treatment objectives.


Click on the icons below to learn more about the process optimization, unparalleled flexibility, energy efficiency, and straightforward operation that the FlexZone system provides.

  • energy
  • flexiable
  • process
  • energy
Energy Efficiency
  • The FlexZone system delivers up to 50% energy savings during periods of low loading by turning off unnecessary aeration and enabling BioMix mixing.
  • The system provides the ideal blend of oxygen delivery and mixing without over-aeration and wasted energy.
  • Since decoupled mixing and aeration provide unmatched turndown capability, the FlexZone system efficiently matches aeration delivery to oxygen demands.
Unparalleled Flexibility
  • The FlexZone system automatically adjusts the bioreactor between anoxic, low dissolved oxygen (DO), and aerobic environments in real-time to improve carbon management and optimize current and future nutrient removal.
  • Unlike conventional aeration systems with limited turndown capabilities, the FlexZone system allows for a wide range of operating environments to address reduced oxygen demand.
  • As influent flow and loading conditions continuously change, the FlexZone system allows the bioreactor to adapt to changing conditions over the life of the treatment facility.
  • The FlexZone system can be designed for greenfield treatment facilities or integrated into facility upgrades utilizing existing equipment, including diffusers, blowers, and instrumentation.
Process Optimization
  • The system matches the volumetric process environment to influent flow, load, and temperature changes.
  • The FlexZone system enables improved nitrogen and phosphorus removal.
  • Dynamic treatment environments allow for reduced chemicals for carbon addition, alkalinity supplementation, and phosphorus precipitation.
Straightforward Operation
  • The FlexZone system provides dynamic process volume control, eliminating the need for fixed process volumes segregated by baffle walls.
  • Using instrumentation and control algorithms, the FlexZone system automatically adjusts aeration and mixing settings to create a bioreactor environment that is either anoxic, low DO, or aerobic.
  • Maintenance of FlexZone equipment is minimal. Equipment outside of the tank is easy to access, and maintenance of in-tank equipment is limited.

Want to learn more about FlexZone Adaptive Process Volume System?


energy savings

The FlexZone system eliminates unnecessary aeration by integrating a BioMix Compressed Gas Mixing System with diffused aeration equipment to allow for aeration, mixing, or SyncroMix — which is concurrent operation of BioMix and diffused aeration.

The example below compares the operation of a treatment plant in a resort town using a fixed conventional aeration approach with limited turndown versus the FlexZone system. The FlexZone system automatically transitions the aerated volume to mix and/or SyncroMix to meet the oxygen demand, providing unmatched turndown and energy savings.

where it applies

Ideally suited for anaerobic selectors, anoxic selectors, mixing limited tanks, and bioreactors, the FlexZone system is an excellent fit for both municipal and industrial wastewater treatment. The process is an ideal solution for retrofits of existing facilities as well as greenfield designs.