TOWARDS AN ASM1 – ADM1 STATE VARIABLE INTERFACE FOR PLANT-WIDE WASTEWATER TREATMENT MODELING

Plant-wide wastewater treatment modeling that combines the modeling of liquid and solids streams into one overall model is becoming increasingly popular. The idea of whole-plant modeling is complicated by the fact that the models used for each unit process have been for the most part developed in isolation, typically without consideration of the whole treatment process or other unit process models. Hence, each unit process model often uses a different set of state variables. This is especially true if the models were developed to describe fundamentally different biological processes like aerobic and anaerobic treatment. To overcome these differences and facilitate plant-wide modeling, model interfaces are used as a means to convert state variables from one model into state variables of a different model. Recently, there has been significant interest in incorporating a new anaerobic digestion unit process model – ADM1 (Batstone et al., 2002) into the COST and IWA simulation benchmarks (Alex et al., 1999; Pons et al., 1999; Copp, 2001; Copp et al., 2002) to create a whole-plant simulation benchmark. To do this, an interface is needed to convert the activated sludge state variables to the anaerobic digestion state variables and visa versa. Standardized model interfaces are an essential component for allowing objective comparisons of simulation results within the wastewater treatment modeling community. This paper describes such a state variable interface.