Biological Process 5 Stage Biological Nutrient Removal (BNR)
The Biological Process 5 Stage BNR consists of:
- Anaerobic Zone
- Anoxic-1
- Aeration
- Anoxic-2
- Re-aeration Zone
These stages contain microorganisms that perform specialized functions to remove nitrogen, phosphorus and BOD
Final Clarification
Final clarification or settling consists of 4 final clarifiers and 6 return sludge pumps. As the flow leaves the 5 stage BNR process it contains solids and microorganisms which will settle when it reaches the final clarifiers. Some of these biological solids will then be pumped back to the front of the 5 stage BNR process to keep the organisms in the system. A small amount will be pumped to the solids treatment process for disposal. The flow leaving the final clarifiers flows by gravity to final filtration. The flow is routed through 6 filters to remove the small amount of solids that still remain.