AAO (Anaerobic – Anoxic – Oxic). AAO technology is a biological treatment process that continuously applies many different microorganisms: Anaerobic, Anaerobic, and Aerobic microorganisms to treat waste. Under the effect of decomposing pollutants by microorganisms, the pollutants are treated before being discharged into the environment.

1. Operating principle

  • Wastewater treatment by microorganisms stick on suspended solids like CAS. However AAO or AO process is more comprehensive and improve many shortcomings of CAS process
  • Process reaction is aerobic microorganisms (tank aeroten)
  • Key bio reaction processes include: anaerobic, annoxi and aerobic

2. Advantages

  • Cheap investment cost because the system’s cost mainly include construction cost, some key equipment such as aeration, pump, mixer. No advanced technology is applied.
  • Produce less surplus sludge compared to CAS because anaerobic and anoxic microorganisms help to treat BOD more comprehensively
  • Outlet water quality can meet B or A standard, depend on the size of tanks
  • Consume less power compared to CAS

3. Disadvantages

  • Outlet water quality depends on sedimentation ability of activated sludge and size of tanks. If want good outlet water quality and less fluctuation of quality, will require huge land/ space to build up system
  • Concentration of activated sludge in CAS system normally remains in the range from 3-5g/L, so that sludge can settle down, If Concentration is higher, sludge can over flow or turbility of outlet water may increase
  • Outlet water quality maybe not stable, because sedimentation of sludge depends on many factors such as temperature, MLSS concentration, organic load and hydraulic load of inlet waste water, etc
  • Footprint required is still large
  • Require disinfection chemicals

4. Common design




***Vui lòng đọc kỹ yêu cầu về Điều khoản sử dụng – Bản quyền trước khi sao chép hoặc trích dẫn nội dung và hình ảnh của website.

Trang web này thuộc bản quyền của Công ty TNHH Quốc tế NGO (NGO International). Bất kỳ hình thức sử dụng hoặc sao chép một phần hoặc toàn bộ nội dung dưới mọi hình thức đều bị nghiêm cấm, trừ trường hợp được sự cho phép rõ ràng bằng văn bản từ Chúng tôi.