Atmospheric Diffusion and Dispersion

Specific Foundation / Core

After successfully completing the course the students have a deeper knowledge on physical and chemical processes of dispersion of pollutants in the atmosphere as well as their removal mechanisms. The students also acquire theoretical background on the use of air quality models and they apply this knowledge on Gauss plume models

• Air pollution and principles of air quality management. Air Quality Indices. • Atmospheric dispersion: Processes and factors affecting. The atmospheric dispersion cycle. Units of atmospheric pollutant concentration. Exercises. • Atmospheric pollutants: Classification – Properties – Sources – Effects. Particulate matter. Exercises. • Spatial and temporal scales of dispersion. Atmospheric dispersion models I: Basic definitions - Fields of applications - Types - Classification. • Atmospheric dispersion models II: Structure - Lagrangian and Eulerian approach. Examples of simple models application. • Turbulent diffusion – Theoretical treatments of the turbulent diffusion with emphasis on gradient transfer theory. Exercises. • Gaussian plume modelling I: Gaussian distribution - Assumptions – Gaussian plume equation - Pasquil Stability class -Determination of the standard deviations of the concentration distribution – Accuracy of estimates. • Gaussian plume modelling II: Expanded Gaussian plume equations for point stack. Equations for specific situations. Nomogram for determination of distance to ground level maximum and maximum concentration. Exercises. • Practical assignment: Demonstration of the Gaussian plume model RAM (theory and use). Application of the RAM model to calculate the dispersion from industrial stacks. Evaluation of the results. • Variation of wind speed with height. Effective height of emission. Buildings and stack effects on the atmospheric dispersion. Exercises. • Plume rise: Buoyant and momentum rise. Final rise for unstable-neutral and stable conditions. Gradual rise. • Atmospheric removal processes: Chemical transformations - Gravitational particle sedimentation - Dry deposition – Wet deposition. Exercises.

30-06-2016