Aeration tank and secondary clarifier as one system. in "Activated Sludge Separation Problems: Theory, Control Measures, Practical Experieces. Eds. Rossetti S., Tandoi V., Wanner J.

Traditionally the activated sludge process is treated as two stage process. The first stage (aeration basin) is described in terms of biological processes while the description of the second stage concentrates on processes of biomass separation and thickening. The modern approach to the activated sludge process looks at both the biological and the separation stage as one system. The aim of this chapter is to explain the interactions between the two parts of the activated sludge system.