Application of the IWA ADM1 model to simulate anaerobic digester dynamics using a concise set of practical measurements

This paper demonstrates how a complex model like the IWA Anaerobic Digestion Model no. 1 can be applied to gain more insight in the anaerobic process and particularly in the dynamics of the digester. The illustrated modelling approach avoids laborious measurements to characterise the influent according the extensive list of components defined in the model. It rather uses the model to make a better characterisation of the inflow. The model is applied to simulate a digester that was originally designed as a CSTR, i.e. with solids retention time equal to the hydraulic retention time. Because it is not practical to completely achieve this condition, an update to the model implementation is introduced to have a solids retention time that is proportional to the hydraulic retention time, i.e. with less efficient retention during overload conditions. The update is different from having a fixed difference between the two retention times as suggested for the standard model implementation for high rate reactors. The introduced approach shows better results for the illustrated application. Moreover, it proves that it can be more suited for high rate reactors operated under high flow dynamics.