He has experience with modeling methodologies, model-based process optimization, and process control. His wastewater modeling experience not only includes biological models, but also hydrodynamic models applied to activated-sludge and membrane bioreactor systems. Nopens is the current president of the Belgian committee of IWA, member of the Steering Committee of the IWA Water Climate and Energy Programme, and part of the Management Committee of the IWA Environmental Engineering Education Specialist Group.