A biofilm-based pre-treatment solution to protect, extend and regenerate your downstream biological process

The BAS™ biofilm activated sludge solution is an optimally designed combination of the AnoxKaldnes™ MBBR biofilm technology and conventional activated sludge.

When the two technologies are positioned in series they create optimal conditions for organics removal, reduced sludge production, and the development of activated sludge with excellent settling characteristics. BAS™ works both for industrial and municipal customers looking at new wastewater treatment plants or at upgrading their existing activated sludge assets.

An activated sludge process is efficient and may produce satisfactory results. When subjected to varying conditions such as organic loading, the system may become unstable and result in conditions such as sludge bulking.

The BAS biological process uses MBBR as pre-treatment to remove much of the easily biodegradable COD and acts as a buffer to protect the AS system from peak loads. This promotes a stable and more efficient activated sludge process with improved sludge settling characteristics.


Advantages of utilizing MBBR technology:

  • Extends the capacity of the existing AS system
  • Protects the AS system from high/fluctuating organic loads
  • Protects the AS system from toxic loads
  • Improves AS system efficiency
  • Improves AS effluent sludge characteristics 
  • Easy implementation with little disturbance to normal operations


A BAS system offers the advantages of MBBR:

  • Compact footprint
  • Simple to operate
  • Flexibility in choosing downstream separation
  • Robust and stable with influent changes
  • Easy to retrofit to existing infrastructure


The BAS treatment process was developed based on modern biotechnological principles and the MBBR technology. It has been used to upgrade or replace conventional activated sludge systems. The process has been successfully applied worldwide across municipal and industrial sectors and over a wide range of plant sizes.


AnoxKaldnes’ technologies are found in more than 1,200 treatment plants around the world. Contact us for references related to your specific needs.

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