Semester project fall 2024/25: Developing a thermodenuder

An important property of aerosols related to their chemical composition is their volatility, which affects aerosol lifetime and fate in the atmosphere as well as giving hints on the origin of the aerosols. However, vertical profiles of aerosol chemical composition and volatility distributions are lacking due to missing instrumentation.

To fill this gap, we are developing a novel thermodenuder system in collaboration with the university of applied science HES-SO Valais. The thermodenuder includes a heating section where components of the aerosol are evaporated based on their volatility, followed by a denuder section where the evaporated gas-phase is removed. The particle size distributions at different temperatures will be measured by a scanning mobility particle sizer. The whole package will be both light-weight and energy-efficient enough to be flown on our helikite platform in order to obtain vertically-resolved data.

Before first deployments in the field, the performance of this prototype thermodenuder needs to be characterised. This semester project aims to understand the evaporation behaviour of aerosols inside of the thermodenuder. In particular, this will involve

  • Characterization of the temperature profile inside the TD
  • Experimental characterization of particle losses at different temperatures
  • Understanding the time taken for temperature ramping and coming up with temperature ramp settings for Helikite operation
  • Measurements of evaporation of nebulized standard compounds

The semester project will therefore be mainly based on laboratory work and is a good chance to get experience with aerosol instrumentation.

Please contact Mihnea Surdu ([email protected]) and Julia Schmale ([email protected]) if you are interested.