Corso di laurea magistrale in Chimica dell'Ambiente

The purpose is to present to the students an overview of the most important reactions that take place in the troposphere and stratosphere, both organic and inorganic. Their impact onto the climate, air quality, and human health is also discussed. Also some aspects of the "Green Chemistry" are presented. Information on the atmospheric reactions mechanisms is given (with a part dedicated to combustion processes). How field studies, experimental laboratory investigations, and theoretical-modelistic studies are intertwined is stressed, as the reach and limits of different methods of investigation. Through their lab work, the students acquire confidence on the last aspect, by carrying out quantum mechanical computations on simple reaction pathways.

KNOWLEDGE AND UNDERSTANDING

At the end of the course, students gain a comprehensive understanding of the complex web of atmospheric organic reactions that occur as a result of anthropogenic or natural emissions of organic molecules into the troposphere. This includes both gas- and heterogeneous-phase chemistry, as the course also examines the transition from molecular aggregates to particulate matter, particularly carbonaceous particles, and the reactions that can occur at the gas-solid interface.

APPLYING KNOWLEDGE AND UNDERSTANDING

The course provides the fundamental concepts and knowledge necessary to predict the evolution of tropospheric oxidative processes and explain the possible major reaction products.

MAKING JUDGMENTS

Students are expected to develop the ability to critically evaluate information obtained from literature.

COMMUNICATION SKILLS

Students will be able to communicate the knowledge acquired in the environmental field using clear and understandable technical-scientific language to both specialist and non-specialist audiences.

LEARNING SKILLS

By the end of the course, students will be able to predict and critically analyze the numerous complex reactions involving organic molecules in the atmosphere. The presence of theoretical lessons and laboratory experiences stimulates and enables continuous learning.

The acquisition of the above-described knowledge and skills will be assessed during the examination.

An overview of atmospheric problems. Vertical structure of the atmosphere. Irradiation and photolysis of O₂, O₃, NO₂, NO₃, carbonyl. Kinetic analysis af the data. Natural lifetime and half-lives. Dependance of the reaction rate from T and P. Arrhenius equation. Transition State Theory. Diurnal and nocturnal oxidation of methane and carbon monoxide. HO_x cycles. Alkane oxidation. Alkyl, Alkyl peroxyl, and alkoxyl radicals. Reaction channels and branching ratios. Oxidation of alkenes triggered by HO and NO₃. Ozonization of alkenes. Oxidation of alkynes. Experimental and theoretical studies on the reaction mechanism. Oxygenated compounds. Aromatic hydrocarbons. Kinetic studies on the oxidative degradation. Some information on theoretical studies of the oxidation mechanism. Polycyclic Aromatic Hydrocarbons (PAH) and their association with the atmospheric particulate. Photolysis and oxidation (functionalization) by HO, NO₃, O₃, etc. Aerosol. Multimodal nature of the atmospheric particulate. In particular, origins, composition and role of the carbonaceous particulate. Chemistry of the stratosphere. Transport of pollutants from troposphere to stratosphere. The Chapman cycle and the "ozone hole". Other cycles. Green chemistry: principles and applications (dimethyl carbonates, ionic liquids and DES, supercritical fluids, perfluorinated compounds, microwaves, water). Examples from the recent literature.  Combustion: types of flames, H₂/O₂ reaction, low and high-temperature mechanisms of CH₄ andC₆H₆ oxidation at low and high-temperature, equilibrium, partial equilibrium, quasi-steady state approximation, NO and CO₂ formation.
Introduction to the lab work: theoretical tools, programs (Gaussian and Gaussview), model systems to be studied as regards reaction mechanisms. Lab work.

Lessons (6 credits, i.e. 4 of lessons and 2 in the lab). To attend the lectures is not mandatory, just advisable. The attendance to the lab is compulsory.

The course is held in presence.
The didactic material is published on Moodle platform.  

The oral exam, lasting approximately 30 minutes, aims to verify the clarity of ideas and the clarity of presentation with which the student explains the topics proposed in the course. The presentation focuses on the examination of typical organic reactions, in the atmosphere, of a selected class of organic species (alkanes, alkenes, alkynes, aromatic hydrocarbons, etc.), with particular attention to reaction mechanisms. This is considered within a framework that includes aspects of chemical kinetics and photochemistry, as well as the interplay with the action and evolution of reactive organic species (VOCs).
The exam takes place in person.

On the course's Moodle page, there is a quiz with 30 questions covering all the topics in the syllabus, allowing the student to optionally self-assess their preparation in view of the exam. The score of the optional self-assessment does NOT count towards the exam grade.

The laboratory includes a final test on the Moodle platform (31 multiple-choice questions).

The overall grade, expressed in /30^th, is the arithmetic mean of the laboratory test and the oral exam.

Communication with students: teacher is available to answer questions by email or, on request, by meeting on Webex. 

For optional in-depth study on the theoretical part of the laboratory:

Andrea Bottoni
Introduzione alla chimica organica computazionale
2023
Edises
ISBN: 9788836231638

To attend the lectures is not mandatory, just advisable. The attendance to the lab is compulsory.

Students with DSA or disabilities are kindly requested to familiarize themselves with the support procedures (https://www.unito.it/servizi/lo-studio/studenti-con-disabilita and https://www.unito.it/accoglienza-studenti-con-disabilita-e-dsa) at the University, especially the necessary procedures for in-exam support (https://www.unito.it/servizi/lo-studio/studenti-con-disabilita/supporto-agli-studenti-con-disabilita-sostenere-gli-esami).