Machine learning and mechanistic modelling of nitrous oxide emissions – presentation of two MSc thesis projects

Two MSc thesis projects focusing on machine learning and mechanistic modelling of nitrous oxide emissions from municipal wastewater treatment plants will be presented online on 2 and 3 June.

Jesper Bergman, an environmental engineering student at Uppsala University, will present his thesis online on 2 June. He has used mechanistic modelling to study how different operating strategies affect nitrous oxide emissions. His starting point was a calibrated process model for Kalmar WWTP, which he expanded to include processes for nitrous oxide formation, in order to investigate how much nitrous oxide is emitted from the biological stage in different scenarios: with and without flexible zones in the biological stage. No emissions measurements for nitrous oxide were available for this work.

Jonas Tornkvist and Malte Törnqvist, chemical engineering students at Lund University, will present their thesis Correlation analysis of nitrous oxide emissions at Klagshamn WWTP using neural networks online on 3 June. They began their work with a correlation analysis in which both linear and monotonic relationships between process variables and nitrous oxide emissions were studied. A key part of the analysis was the introduction of time delays based on hydraulic retention time, which proved crucial for obtaining process-relevant relationships. Subsequently, a sequential machine learning model was developed in which each zone of the activated sludge plant was represented separately, whilst connections between the zones were taken into account. The model was used as a differentiable component in a gradient-based optimisation, which enabled the simulation of how changes in aeration affect both nitrous oxide emissions and ammonium effluent.

Interested?

Would you like to listen in and perhaps discuss the results with the MSc students mentioned above? Please contact David Gustavsson.

Belongs to project

Reduce the emissions of nitrous oxide from wastewater treatment