37377 - Atmospheric Pollutants Transportation and Dispersion Processes

Academic Year 2023/2024

  • Moduli: Luca Evangelisti (Modulo 1) Massimo Andretta (Modulo 2)
  • Teaching Mode: Traditional lectures (Modulo 1) Traditional lectures (Modulo 2)
  • Campus: Ravenna
  • Corso: Second cycle degree programme (LM) in Environmental Assessment and Management (cod. 5900)

Learning outcomes

This course provides the student with a basic knowledge of the fundamental principles necessary for calculating mass and energy balances involved in transport processes, basic notions of the physics of the lower atmosphere and the dispersion and deposition mechanisms of pollutants. This will enable the student to use the most widespread simulation models for atmospheric concentrations and ground deposition of pollutants and to compare the results with air quality reference values.

Course contents

Processes of transport and diffusion of pollutants in the Atmosphere.

Transport processes. Mass balance. Input, output and reaction flows. Common kinetic equations. Differential balance for individual components. Sedimentation; Stoke's Law. Dynamic and kinetic viscosities. Reynolds Number. Conductance and conductivity; salinity.

Molecular and turbulent diffusion. Fick's Laws. Factors influencing diffusivity. Atmospheric stability. Pasquill's Model for chimney plumes. Estimation of ground pollutant concentrations as a function of distance from the stack and various parameters; computer simulations.

Energy balance. Bernoulli Equation for both incompressible fluids and gases. Decrease in atmospheric pressure and temperature with altitude. Bouyancy.

Variations in the distribution of volatile atmospheric components with altitude. Problem of ozone and relevant reaction cycles. Thermal energy; transport through thermal conduction, convection and irradiation (Stefan-Boltzmann and Wien laws); Greenhouse effect. Atmospheric pollution from combustion processes; Yields of Otto (petrol engine) and Diesel (diesel engine) Cycles.

Elements of the physics of the lower atmosphere: convective and diffusive layers. The geostrophic wind and the spiral of Ekman. Theoretical foundations of Gaussian models. Effective heights of plume emissions and the semi-empirical formulae for their estimation. Models for deposition under dry and humid conditions. Elements of air quality legislation and regulations. Methods of calculation for comparing modelling results and reference values of environmental regulations. Puff models, finite time emission models and particulate models.

Computer excercises on the various models for estimating air quality and ground depositions.


Updated teaching material is provided for lessons and can be found through username and password at INSEGNAMENTI ONLINE of the University of Bologna. Other recommended texts are:

- R. Francesconi, Notes on Environmental Physical Chemistry, CLUEB, Bologna, 2002.

- G. Finzi (ed.): "Air Quality Management", MCGraw-Hill, 2001.

- S.R. Hanna, G.A. Briggs, R.P.Hosker Jr.: "Handbook on Atmospheric Diffusion", U.S: Dept. Of Energy, NTIS, 1982.

Teaching methods

The course consists of lectures in which the notions are introduced with the support of the classic blackboard or video projection. Furthermore, numerical exercises and computer simulations will be carried out during the course in order to understand the notions acquired during the theoretical part.

Assessment methods

The verification of learning takes place through the final exam only, which ensures the acquisition of the knowledge and skills expected through the performance of an oral test. Often one of the topics covered is chosen by the candidate.

The final mark expresses an evaluation of the contents expressed during the final test.

Teaching tools

Teaching material: the teaching material presented in class will be made available to the student in electronic format via the internet. Such material should be printed and brought to the lesson.

To obtain the didactic material: http://virtuale.unibo.it

Username and password are reserved for students enrolled at the University of Bologna.
Blackboard, portable calculator, video projector, computer lab for exercises, internet connection.

A visit to the ARPA control center and the Rocca Brancaleone control unit (Ravenna) is scheduled.

Students who need compensatory tools for reasons related to disabilities or specific learning disorders (SLD) can directly contact the Service for Students with Disabilities (disabilita@unibo.it) and the Service for Students with learning disabilities (dsa@unibo.it) to agree on the adoption of the most appropriate measures.

Office hours

See the website of Luca Evangelisti

See the website of Massimo Andretta


Quality education Climate Action Life on land

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.