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• 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 envi-ronments

• Chemical structure and physical properties and reactivities

• Quantification of phase transfer, transformation and transport pro-cesses

• Mathematical models based on combining all relevant elements to assess behavior of organic chemicals

R.P. Schwarzenbach, Eawag/ETH, Switzerland

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• Textbook

P.M. Gschwend, MIT, USA

D.M. Imboden, ETH, Switzerland

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• 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)

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• DDT (dichlorodiphenyltrichloroethane)

• In 1962, Silent Spring by American biologist Rachel Carson

• DDT and other pesticides may cause cancer and that their agri-cultural 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

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• Production/Usage and Environmental Impacts

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• Issues of anthropogenic organic chemicals in the environment

• Acute contamination (chemical accidents, spills, waste dump sites etc)

2007 South Korea oil spill

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• 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

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• Issues of anthropogenic organic chemicals in the environment

• REACH, European Union Regulation of 18 December 2006

• Registration, Evaluation, Authorisation and Restriction of Chemi-cal

• addresses the production and use of chemical substances, and their potential impacts on both human health and the environ-ment

• 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

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• The needs and tasks of environmental or-ganic chemistry

• Impacts of organic chemicals (existing or new) to humans and ecosystems

• The processes that govern the transport/transfer and transfor-mations of anthropogenic chemicals in the environment

• Identity unchanged processes: transport/mixing and phase trans-fer

• Identity changed processes: chemical, photochemical and biolog-ical transformation processes

• The effects of such chemicals on organisms (including humans), organism communities, and whole ecosystems

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From Schwarzenbach et al., Science 2006

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• Environmental processes in a lake

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• General scheme for evaluation of the environmental behavior of anthropogenic organic compounds

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• Structure of the book and the scope of the lecture

Part I. Ch.2. Introduction to environmental or-ganic chemicals

Part II. Phase transfer (partitioning)Ch3. theory of partitioning processesCh4. vapor pressureCh5. water solubilityCh6. air-liquid partitioningCh7. organic liquid-water partitioningCh8. organic acids and basesCh9. partitioning to organic mattersCh10. partitioning to living mediaCh11. partitioning to inorganic surfaces

Part III. Transformation processCh12. thermodynamics and kineitc con-cepts Ch13. chemical transformation-hydrolysisCh14. chemical transformation-redox reac-tionsCh15. photochemical transformation-directCh16. photochemical transformation-indi-rectCh17. biological transformaiton

Part IV. Transport and mixingCh18. Transport by random motionCh19. Transport through boundariesCh20. Air-water exchangeCh21. box modelsCh22. models in space and time

Part V. Environmental systems and case studiesCh23. Ponds, lakes and oceansCh24. RiversCh25. groundwater

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• Schedule

Date subject Ch.

Sep 3Sep 5

Introduction to environmental organic chemistry-1,2

Ch.1Ch.2

Sep 10

Sep 12

No class (faculty meeting)

Introduction to environmental organic chemistry-3

Ch.2

Sep 17Sep 19

Thermodynamics and kinetics of transformation reactions-1,2

Ch.12

Sep 24Sep 26

No class (military service) Thermodynamics and kinetics of transformation reactions-3

Ch.13

Oct 01Oct 03

No classNo class

Oct 08

Oct 10

Hydrolysis and other nucle-ophilic substitution-1Undergraduate entrance exam (make up)

Ch.13

Oct 15

Oct 17

Hydrolysis and other nucle-ophilic substitution-2,3IERC symposium (make up)

Ch.13

Date subject Chapter

Oct 22Oct 24

Middle examRedox reactions-1

Ch 14

Oct 29Oct 31

Redox reactions-2Redox reactions-3

Ch.14

Nov 5Nov 7

Direct photolysis-1Direct photolysis-2

Ch.15Ch.15

Nov 12Nov 14

Direct photolysis-3Make-up

Ch.15Ch.16

Nov 19Nov 21

Indirect photolysis-1Indirect photolysis-2

Ch.16Ch.16

Nov 26Nov 28

Indirect photolysis-3Biological transformation-1

Ch.16Ch.16

Dec 3Dec 5

Biological transformation-2Biological transformation-3

Ch.16Ch.16

Dec 10Dec 12

SummaryFinal exam

1) Mon. Wed. 9.00 – 10:20, SESE building 209/2102) Three classes for each chapter 3) Presentation for answering questions at the end of each chapter4) middle and final exams5) Notice by email or http://env1.gist.ac.kr/~wqtl

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• Evaluation

Items Points note

Attendance -1 for each missing class

Middle exam 30

Final exam 30

Homework (p-resentation for question)

20 6 homeworks

Quiz 20 2 or 3 quizs

Total 100

• Contact/helpYunho Lee, SESE building 308, available time: Monday 10.30 – 12 amyhlee42@gist.ac.kr

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• 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

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18

19

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• Bond angles

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Isomers: compounds with the same molecular formula but different structural formulas

• Structural isomers: the atoms and functional groups are joined to-gether in different ways

• Stereoisomers: the bond structure is the same, but the geometrical po-sitioning 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)

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Ch-2.3. Classification, nomenclature, and examples of envi-ronmental organic chemicals

• Classification by physical/chemical properties: VOCs, hydropho-bic compounds, surfactants, solvents

• Classification by source or use: solvents, plasticizers, pesticides, dyes and pigments, mineral-oil products

• Classification by chemical structure-functional groups: hydro-carbons, organohalogens, oxygen-, nitrogen-, and sulfur-contain-ing compounds

• Systematic (IUPAC) names vs trivial names: lindane

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• Hydrocarbons

• Fossil fuels and synthetic processing of fossil fuels

• Liquid petroleum products 3 billion metric tons annually

• Typically hydrophobic

• Aliphatic, alicyclic, and olefinic hydrocarbons

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• Hydrocarbons

• BTEX: gasoline constituents, solvents, common ground-water 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

• Aromatic hydrocarbons

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• 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 depletionGlobal warming potential

Need to develop alternatives

Top groundwater pollutantsPersistent, mobileReductive dehalogenation

• Organohalogens

To date, > 1 million metric tons produced

Waxes, printing inks, paints, lacquers, capacitor dielectric fluids, trans-former coolants, hydraulic fluids, heat-transfer fluids, lubricants, plasticizers, fire retardants

Some of them are banned or restricted in many coun-tries

Polychlorinated hydrocarbons

• Organohalogens

X = Cl, Br, I

Halogenated compounds from chlorination of water or bleaching processes in the pulp and paper industry

• Oxygen-containing functional groupsOxygen forms polar bonds

-OH: both as H-donor and H-acceptor

-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 contami-nants, flame retardants

• Oxygen-containing functional groups

Aldehydes and ketones as reac-tive intermediates

H-acceptor, solvents

Carboxyl acids, anionic formsBoth H-acceptor and H-donors

Industrial production and envi-ronmental transformation prod-ucts 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 groupsAmino groups: natural (amino acids, amino sugars) and an-thropogenic (anilines etc)Cationic ammonium species (both H-acceptors and H-donors), surfactant Aromatic amines as -electron donor, azo dyes

Nitro groups: explosives, agro-chemicals, dyes, atmospheric formation by nitrationStrong electron-withdrawing character (acidity, oxidant) and delocalize -electron (light absorption), reduction to ni-troso, hydroxylamine, and amines

• Sulfur-containing functional groups

• Sulfur-containing functional groupsSulfur valence-shell expan-sion different from oxygen

Less electronegative, more nucleophilic than oxygen

Special double bond be-tween S and O (d-orbital)

Low-molecular weight mecarptans (reduced sulfur) as natural and anthro-pogenic source (herbicides, lower toxicity or target toxic-ity)

Oxidized sulfur (sulfonic acid) LAS as major surfac-tants, anionic azo dye, whitening agents, detoxicifi-cation strategies

Sulfonic acid derivatives, sulfon-amides

• 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 com-pounds)

Pesticides

Pharmaceuticals