CHEMISTRY OF THE ENVIRONMENT
Learning outcomes of the course unit
The objective of this course is to provide the basic concepts for the comprehension of:
1) origin, reactions, transport of chemicals in the atmosphere, water, soil as well as their effects an the human health an the natural environment
2) new industrial and research approaches for the synthesis of chemicals through low impact industrial processes
3) reference legislation frame concerning waste management and ”chemical reading” of Decree 334/99 (Seveso 2).
Course contents summary
Concept and definition of pollutant
Molecular structure physical chemical properties relationship, Kow, Henry’s law and Henry’s constant
Relationship between molecular structure ad reactivity: short accounts on basic thermodynamic and kinetic concepts
Abiotic transformation and degradation processes: oxidation, hydrolysis phototransformation and photodegradation, estimation of photolysis rate constants or phototransformation rate constants, example of calculation
Short accounts on biotransformation and degradation processes, kinetics of transformation and degradation
Petroleum hydrocarbons: chemical nature of petroleum and its average composition, the industrial chemistry of petroleum. Hydrocarbons in the environment: dispersion, evaporation, dissolution, photooxidation, microbial transformation. Petroleum and aquatic organisms.
Polychlorinated biphenyls (PCBs) and dioxins: nomenclature, origin, their physical chemical properties, environmental distribution and behaviour, toxicity, ITEF.
Synthetic polymers: classification and nomenclature code, methods for the synthesis of polymers. Environmental characteristics of synthetic polymers: combustion, biodegradation, photodegradation, recycling.
Pesticides: chemical structure and synthesis of chlorinated hydrocarbon pesticides, organophosphates, carbamates, pyretrins and pyretroids. Physical chemical properties of pesticide, their environmental properties, toxicity, bioaccumulation properties, ecological effects.
Polycyclic aromatic hydrocarbons: their chemical nature, origin, environmental behaviour, carcinogenicity and effects on human health and the environment.
Soaps and detergents: classification and their synthesis, the active cleaning agents, builders, bleachers. Toxicity, biodegradation, sorption and bioaccumulation.
Chemistry of natural water: carbon and nitrogen transformations in natural water bodies, salinity of seawater, vertical depth profile of seawater composition.
Water pollution: influence of chemical processes on dissolved oxygen, BOD, kinetic of BOD reduction, seasonal variation and vertical profile of dissolved oxygen, anaerobic degradation processes, the effects of organic wastes.
Atmospheric chemistry and pollution: vertical profile of atmospheric temperature and pressure, the role of OH radical, ozone cycle, hydrocarbons in the atmosphere. CFCs: classification, CFCs and the ozone layer, their ODP and GWP. NOx and SOx: sources, toxicity and their impact on the environment.
Soil contamination: sources and distribution of contaminants, soil/water partition process, soil/organism process, ecological and health effects of soil contamination.
Distribution of chemicals in the environment: two-phase partition processes in the environment, the fugacity concept, fugacity and chemical distribution, the fugacity capacity factor (Z), chemical distribution in a model environment, example of distribution calculation.
Basic principle of Green Chemistry: comparison between classical and low impact innovative industrial synthesis of chemicals, the ideal reaction, atom economy, the Environmental factor (E), use and selection of the reaction media.
Chemical aspects on waste management within the Decree 22/97 (D. Ronchi): waste classification. Chemical aspects of the low 334/99 (Seveso 2 o grandi rischi).
An integral part of the course will be the a cycle of seminars, organized autonomously by groups of students focused on subjects of the frontal lectures and aimed at deepening aspects of environmental chemistry in a wider conception.
Basic Concepts of Environmental Chemistry Des W. Connell; Lewis Publishers, N.Y.(1997).
Environmental Organic Chemistry R.P. Schwarzenbach, P.M. Gschwend, D.M. Imboden; J. Wiley& Sons, Inc. (1993).
Teaching method: frontal lectures, integrated with deepening seminars, organized autonomously by groups of students, focused on topics of the theortical part of the course.
Evaluation criteria: The ability of the candidate to autonomously accede to primary literature sources concerning a specific environmental issue and frame it in a critical manner within the topics of the course will be evaluated.