The Schreiber Continuously Sequencing Reactor, or CSR, is a Biological Nutrient Removal (BNR) system contained in a single basin. It produces the 3 process phases required for BNR – oxic, anoxic and anaerobic – in one basin. The 3 phases do not occur at the same time in the basin. They occur sequentially – repetitively, over time. During the oxic phase, the entire basin is oxic or aerobic. When the air is turned off, the entire basin becomes anoxic and then ultimately anaerobic. The air is then turned back on and the cycle repeats.

For the CSR, the secret to this “phase sequence-ability” lies in its unique design for complete separation of aeration and mixing. It has a 100% aeration turndown capability, allowing the aeration to be turned off while the CSR applies its low-energy, biologically-friendly, flocculant mixing – without adding air. Through the use of Schreiber FlexControls, the CSR process can be advanced to meet the most stringent of requirements for today and the future.

Please contact Schreiber at 205-655-7466 or email to  receive a quote or to obtain purchasing information.


  • Biological Wastewater Treatment
  • Wastewater Aeration
  • Industrial Waste Aeration
  • Municipal Water Reclamation Facilities
  • BNR Applications
  • ENR Applications


  • BNR in a Single Basin
  • Energy Efficient (30% more efficient)
  • Separation of Aeration and Mixing
  • Operator Friendly Process
  • Adjusts Automatically to Variable Influent Loading
  • Engineered and Built for Long Life
  • Easy Maintenance without De-Watering designs
  • Proven System Backed by a Proven Company

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