Interactions within the wastewater system: requirements for sewer processes modelling

Today's focus on wastewater system optimisation necessitates the development of knowledge on the interactions between sewer systems and wastewater treatment, since these interactions have often been neglected in the past. In this paper the question is discussed to what extent it is favourable and possible to include dynamic changes of wastewater quality in wastewater system optimisation studies. The sensitivity of the wastewater treatment works to influent fluctuations proved to be the key issue in determining which sewer processes are involved in the dynamic interactions between sewer systems and treatment works. The preliminary results show the importance of a good description of the transport processes involving the double and suspended fractions.