BAS™ (Biofilm Activated sludge)

An ideal marriage

BAS™ is a biological treatment process that combines the very best from activated sludge and Moving Bed™ biofilm technologies. Careful design of process stages yields an optimal activated sludge stage and a MBBR™ biofilm stage that is robust towards peak and shock contaminant loading conditions. The result is consistently high and reliable treatment efficiency of any type of industrial wastewater.

The initial MBBR™ biofilm unit process shaves the loadings peaks and any toxic inhibition effects while removing 50 to 70 percent of the incoming BOD. This pretreatment achieves 2 to 3 times increased capacity compared to a traditional activated sludge process while also being more compact. Furthermore, the BAS™-process improves activated sludge characteristics making the activated sludge stage more inherently stable with a waste sludge that is easier to dewater.

If already existing tanks at a given site can be retrofitted, a simple BAS™ process upgrade to a faltering activated sludge process can be readily accomplished. Filling one tank with AnoxKaldnes MBBR™ biocarriers creates the BAS™ pretreatment stage that relieves the overloaded activated sludge process. The Moving Bed Biofilm Reactor (MBBR™) stage is optimized to remove as much of the COD as possible.

Nutrient limited BAS™

The nutrient limited BAS™ process is a refined BAS™ strategy to significantly decrease waste sludge production in cases where nutrients must be added to the wastewater. In the biofilm stage, the COD in the wastewater is converted to polysaccharides. These polysaccharides are in turn used to produce biomass in the activated sludge stage. The polysaccharide production and consumption cost the bacteria a lot of energy and this expense limits their growth. Reduced growth means a decreased amount of waste sludge produced and that translates into operations savings.