• Environmental Organic Chemistry
• Assessing the environmental behavior of organic chemicals
• Understanding of how molecular interactions and macroscopic transport
phenomena determine the distribution in space and time of organic
chemicals released into natural and engineered environments
• Chemical structure and physical properties and reactivities
• Quantification of phase transfer, transformation and transport processes
• Mathematical models based on combining all relevant elements to assess
behavior of organic chemicals
1
• Textbook
R.P. Schwarzenbach, Eawag/ETH, Switzerland
P.M. Gschwend, MIT, USA
D.M. Imboden, ETH, Switzerland
2
• DDT (dichlorodiphenyltrichloroethane)
• Synthesized first in 1874
• organochlorine insecticide
• great success in the second half of World War II to control malaria and
typhus
• The Swiss chemist Paul Hermann Müller was awarded the Nobel Prize
in Physiology or Medicine in 1948 "for his discovery of the high
efficiency of DDT as a contact poison against several arthropods.
• After the war, DDT was made available for use as an agricultural
insecticide and produced massively (40,000 tons per year)
3
• DDT (dichlorodiphenyltrichloroethane)
• In 1962, Silent Spring by American biologist Rachel Carson
• DDT and other pesticides may cause cancer and that their agricultural
use was a threat to wildlife, particularly birds
• questioned the logic of releasing large amounts of chemicals into the
environment without fully understanding their effects on ecology or
human health
• the birth of the environmental movement
• Ban of DDT in the US in 1972
• Ban of DDT for agricultural use worldwide under the Stockholm
Convention
4
• Production/Usage and Environmental Impacts
5
• Issues of anthropogenic organic chemicals in the
environment
• Acute contamination (chemical accidents, spills, waste dump sites etc)
2007 South Korea oil spill
6
• Issues of anthropogenic organic chemicals in the
environment
• Chronic contamination (everyday use in industry, household etc)
• Petroleum chemicals
• Solvents
• Polymers
• Pesticides/insecticides
• Pharmaceuticals
• Nanomaterials
• ….
• >300 million tons
7
• Issues of anthropogenic organic chemicals in the
environment
• REACH, European Union Regulation of 18 December 2006
• Registration, Evaluation, Authorisation and Restriction of Chemical
• addresses the production and use of chemical substances, and their
potential impacts on both human health and the environment
• Requires all companies manufacturing or importing chemical
substances into the European Union in quantities of one ton or more
per year to register these substances with a new European Chemicals
Agency
• the strictest law to date regulating chemical substances and will affect
industries throughout the world
8
• The needs and tasks of environmental organic
chemistry
• Impacts of organic chemicals (existing or new) to humans and
ecosystems
• The processes that govern the transport/transfer and transformations
of anthropogenic chemicals in the environment
• Identity unchanged processes: transport/mixing and phase transfer
• Identity changed processes: chemical, photochemical and biological
transformation processes
• The effects of such chemicals on organisms (including humans),
organism communities, and whole ecosystems
9
From Schwarzenbach
et al., Science 2006
10
• Environmental processes in a lake
11
•
General scheme for evaluation of the environmental
behavior of anthropogenic organic compounds
12
•
Structure of the book and the scope of the lecture
Part I.
Ch.2. Introduction to environmental organic
chemicals
Part II. Phase transfer (partitioning)
Ch3. theory of partitioning processes
Ch4. vapor pressure
Ch5. water solubility
Ch6. air-liquid partitioning
Ch7. organic liquid-water partitioning
Ch8. organic acids and bases
Ch9. partitioning to organic matters
Ch10. partitioning to living media
Ch11. partitioning to inorganic surfaces
Part III. Transformation process
Ch12. thermodynamics and kineitc concepts
Ch13. chemical transformation-hydrolysis
Ch14. chemical transformation-redox reactions
Ch15. photochemical transformation-direct
Ch16. photochemical transformation-indirect
Ch17. biological transformaiton
Part IV. Transport and mixing
Ch18. Transport by random motion
Ch19. Transport through boundaries
Ch20. Air-water exchange
Ch21. box models
Ch22. models in space and time
Part V. Environmental systems and
case studies
Ch23. Ponds, lakes and oceans
Ch24. Rivers
Ch25. groundwater
13
• Schedule
1)
2)
3)
4)
5)
Mon. Wed. 9.00 – 10:20, SESE building 209/210
Three classes for each chapter
Presentation for answering questions at the end of each chapter
middle and final exams
Notice by email or http://env1.gist.ac.kr/~wqtl
Date
subject
Ch.
Date
subject
Chapter
Sep 3
Sep 5
Introduction to environmental
organic chemistry-1,2
Ch.1
Ch.2
Oct 22
Oct 24
Middle exam
Redox reactions-1
Ch 14
Sep 10
No class (faculty meeting)
Introduction to environmental
organic chemistry-3
Ch.2
Redox reactions-2
Redox reactions-3
Ch.14
Sep 12
Oct 29
Oct 31
Sep 17
Sep 19
Thermodynamics and kinetics of
transformation reactions-1,2
Ch.12
Nov 5
Nov 7
Direct photolysis-1
Direct photolysis-2
Ch.15
Ch.15
Sep 24
Sep 26
No class (military service)
Thermodynamics and kinetics of
transformation reactions-3
Nov 12
Nov 14
Direct photolysis-3
Make-up
Ch.15
Ch.16
Nov 19
Nov 21
Indirect photolysis-1
Indirect photolysis-2
Ch.16
Ch.16
Oct 01
Oct 03
No class
No class
Nov 26
Nov 28
Indirect photolysis-3
Biological transformation-1
Ch.16
Ch.16
Oct 08
Hydrolysis and other nucleophilic
substitution-1
Undergraduate entrance exam
(make up)
Ch.13
Dec 3
Dec 5
Biological transformation-2
Biological transformation-3
Ch.16
Ch.16
Dec 10
Dec 12
Summary
Final exam
Hydrolysis and other nucleophilic
substitution-2,3
IERC symposium (make up)
Ch.13
Oct 10
Oct 15
Oct 17
Ch.13
14
• Evaluation
Items
Points
Attendance
note
-1 for each missing class
Middle exam
30
Final exam
30
Homework
20
(presentation for
question)
6 homeworks
Quiz
20
2 or 3 quizs
Total
100
• Contact/help
Yunho Lee, SESE building 308, available time: Monday 10.30 – 12 am
yhlee42@gist.ac.kr
15
• Ch2. Introduction to environmental organic
chemicals
Goal: refresh our memories with terminologies and basic chemical concepts
of organic chemistry
Ch-2.2. The makeup of organic compounds
•
•
•
•
•
•
•
•
•
•
Organic compounds? Major elements, heteroatoms
Elemental composition, molecular formula, and molar mass
Electron shells of elements present in organic compounds
Covalent bonding
Bond energies (enthalpies) and bond lengths
The concept of electronegativity
Oxidation state of the atoms in organic molecules
Spatial arrangement of the atoms in organic molecules (VSEPR)
Steroisomerism
Delocalized electrons, resonance and aromaticity
16
17
18
19
• Bond angles
20
Isomers:
compounds with the same
molecular formula but different
structural formulas
• Structural isomers: the atoms and functional groups are joined together in
different ways
• Stereoisomers: the bond structure is the same, but the geometrical positioning
of atoms and functional groups in space differs
• Enantiomers: different isomers are non-superimposable mirror-images of each
other
• Geometric isomers: restricted rotation within the molecule (cis-E and trans-Z)
• Conformational isomers: free rotations around sigma bonds (usually not
separable)
21
Ch-2.3. Classification, nomenclature, and examples of environmental
organic chemicals
• Classification by physical/chemical properties: VOCs, hydrophobic
compounds, surfactants, solvents
• Classification by source or use: solvents, plasticizers, pesticides, dyes
and pigments, mineral-oil products
• Classification by chemical structure-functional groups: hydrocarbons,
organohalogens, oxygen-, nitrogen-, and sulfur-containing compounds
• Systematic (IUPAC) names vs trivial names: lindane
22
• Hydrocarbons
• Aliphatic, alicyclic, and olefinic
hydrocarbons
• Fossil fuels and synthetic
processing of fossil fuels
• Liquid petroleum products
3 billion metric tons annually
• Typically hydrophobic
23
• Hydrocarbons
• Aromatic hydrocarbons
• BTEX: gasoline constituents,
solvents, common groundwater
pollutants
• PAHs:
- combustion of fossil fuels, forest
fires, direct input of mineral oils,
use of creosotes as wood
preservatives
- benzo(a)pyrene, potent
carcinogen
- bioaccumulation
24
• Organohalogens
• Largely anthropogenic source
• F and Cl form strong bonds with carbon, enhance of inertness
(persistence)
• Halogens in organics enhance hydrophobicity, thus increase the
partitioning to organic phases including organisms
Stratosphere ozone depletion
Global warming potential
Need to develop alternatives
Top groundwater pollutants
Persistent, mobile
Reductive dehalogenation
25
• Organohalogens
Polychlorinated hydrocarbons
To date, > 1 million metric
tons produced
Waxes, printing inks, paints,
lacquers, capacitor dielectric
fluids, transformer coolants,
hydraulic fluids, heat-transfer
fluids, lubricants, plasticizers,
fire retardants
Some of them are banned or
restricted in many countries
• Organohalogens
Halogenated compounds from chlorination of water or bleaching
processes in the pulp and paper industry
X = Cl, Br, I
• Oxygen-containing functional groups
Oxygen forms polar bonds
-OH: both as H-donor and Hacceptor
-ROR: H-acceptor
-ROH, dissociation
-15-20 million metric tons per
year
-MTBE: representative
groundwater pollutant
-Dioxins, PCDDs and PCDFs:
produced from incineration
-PBDEs: emerging contaminants,
flame retardants
• Oxygen-containing functional groups
Aldehydes and ketones as reactive
intermediates
H-acceptor, solvents
Carboxyl acids, anionic forms
Both H-acceptor and H-donors
Industrial production and
environmental transformation
products of organics
e.g. atmospheric oxidation of
haloethanes and haloethenes
Carboxylic acid esters
:phthalates as plasticizers
Preventol B2 as roof protection
materials, slow release of mecoprop
• Nitrogen-containing functional groups
• Nitrogen-containing functional groups
Amino groups: natural (amino
acids, amino sugars) and
anthropogenic (anilines etc)
Cationic ammonium species (both
H-acceptors and H-donors),
surfactant
Aromatic amines as -electron
donor, azo dyes
Nitro groups: explosives,
agrochemicals, dyes, atmospheric
formation by nitration
Strong electron-withdrawing
character (acidity, oxidant) and
delocalize -electron (light
absorption), reduction to nitroso,
hydroxylamine, and amines
• Sulfur-containing functional groups
• Sulfur-containing functional groups
Sulfur valence-shell expansion
different from oxygen
Less electronegative, more
nucleophilic than oxygen
Special double bond between S
and O (d-orbital)
Low-molecular weight
mecarptans (reduced sulfur) as
natural and anthropogenic
source (herbicides, lower
toxicity or target toxicity)
Oxidized sulfur (sulfonic acid)
LAS as major surfactants,
anionic azo dye, whitening
agents, detoxicification
strategies
Sulfonic acid derivatives, sulfonamides
• Phosphorus-containing functional groups
P vs N
P typically +III or V oxidation
state
Three single bonds and one
double bonds
Special double bonds
Plasticizer, flame retardants,
pesticides, chelating agent
• More complex structures (e.g. bioactive compounds)
Pesticides
Pharmaceuticals