Stina Edelfeldt, Peter Fritzson

Evaluation and Comparison of Models and Modeling Tools Simulating Nitrogen Processes in Wetlands

The global problem of eutrophication, the enrichment of water bodies by nutrients, has in recent years resulted in an increased interest in non-conventional ways to reduce the amount of nutrients discharged into the environment. One of the more commonly proposed and also used solutions is to append artificial or constructed wetlands as a final step in the treatment of wastewater. However, both the construction of the wetlands and the maintenance thereof are time and resource consuming, hence a high production and maintenance cost. Due to these high costs, tools for modeling and simulation have turned out to be valuable asset in the development of constructed wetlands.In this paper, two ecological models of nitrogen processes in treatment wetlands have been evaluated and compared. These models were implemented, simulated, and visualized in the Modelica language 6. The differences and similarities between the Modelica modeling environment used in this thesis and other environments or tools for ecological modeling have also been evaluated.