A GENERALIZED-APPROACH FOR DYNAMIC MODELING AND SIMULATION OF BIOFILTERS - APPLICATION TO WASTE-WATER DENITRIFICATION

This contribution is devoted to the use of dynamic simulation as a sup port tool to improve the knowledge of biofilters in the general contex t of waste-water treatment. After a brief overview of current waste-wa ter treatment techniques, a general approach for modelling and simulat ion of biofilters in transient states is presented. First of all, a co mprehensive description of the development of the model, highlighting specific characteristics such as the active/deactivated biomass approa ch is presented; discussion of the different phenomena involved is the n pursued. The resulting set of Partial Differential Algebraic Equatio ns (PDAE), with the need for state event detection for filter clogging , is then solved using an extension of the Differential-Algebraic phil osophy coupled with the method of lines. Finally, the validity of the general developed model, as well as the reliability of the numerical a pproach is illustrated through different case studies for denitrificat ion purposes, with plant data comparison. It demonstrates the utility of dynamic simulation to speed up the development of the model phase a nd to improve basic knowledge in a new emerging area. (C) 1997 Elsevie r Science S.A.