Identification of overall degradation in sewer systems from long-term measurements and consequences for WWTP simulations.

In-sewer transformation processes affect significantly design and operation of large wastewater treatment plants. Especially for long-term simulations the degradation has to be considered in order to avoid over- and underestimation. In this paper a method is presented to derive the overall degradation from available operation data. The application of the results in a long-term simulation of a WWTP shows the relevance of the degradation for design and operation of an activated sludge plant.