A New Approach to Modeling Biofilm Reactors: Simulating the Movement of Submerged Free Moving Biofilm Carriers (Xcarriers) ; Nouvelle approche pour simuler les procédés à biofilm : prise en compte de la non-homogénéité du support

International audience ; One-dimensional (1-D) biofilm models have been demonstrated reliable for specific types of biofilm reactor design. It is apparent that the limitations inherent to using mechanistic biofilm models for engineering design does not rely on improved biofilm models, but does rely on improved biofilm reactor models. Thi s notion is important when considering that biofilm reactors containing submerged, free -moving biofilm carriers are the most widely applied biofilm system(s) for municipal wastewater treatment. This paper presents a new biofilm reactor model that considers the impact of submerged free -moving biofilm carrier (Xcarrier) movement on system performance. The model accounts for a hydrodyamic condition characterized as plug flow with back mixing (to model axial dispersion). In addition, the model includes a known and demonstrated 1-D biofilm model (Wanner and Reichert, 1996) and biological process model (ASM 3; Henze et al. 2000). The relevance of this new biofilm reactor model to engineering situations is evaluated by applying it to relevant scenarios and comparing model results.