1 / 125

Envr 725

Envr 725. Tues. and Thurs- 3 credit hours, room 0015 MHRC 11:00 am to 12:15 pm Snow days call 942 4880 or cell 919 614 4730 http://www.unc.edu/courses/2007spring/envr/725/001/Envr725.html Rich Kamens; 966 5452 kamens@unc.edu http://airsite.unc.edu/~kamens/. Textbook

Download Presentation

Envr 725

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Envr 725 • Tues. and Thurs- 3 credit hours, room 0015 MHRC • 11:00 am to 12:15 pm • Snow days call 942 4880 or cell 919 614 4730 • http://www.unc.edu/courses/2007spring/envr/725/001/Envr725.html • Rich Kamens; 966 5452 • kamens@unc.edu • http://airsite.unc.edu/~kamens/

  2. Textbook • Environmental Organic Chemistry by René P. Schwarzenbach, Philip M. Gschwend, and Dieter M. Imboden, John Wiley & Sons, Inc., New York, 2003, ISBN 0-471-35053-2, pages:1313.

  3. UNC outdoor chamber

  4. Gas/Particle partitioning of toxics organics on different aerosols

  5. New UNC Aerosol Smog Chamber

  6. Dual 270m3 chamber fine particle t 1/2 >17 h

  7. From a Modeling perspective Equilibrium Organic Gas-particle partitioning provides a context for addressing SOA Formation • Numerical fitting • Semi-explicit

  8. cis-pinonaldhyde Gas phase reactions C=O C=O O O particle Link gas and particle phases

  9. kon koff particle C=O O kon koff • [ igas] + [part] [ipart] Kp = kon/koff

  10. + CO, HO OH 2, CHO O norpinonaldehyde COOH O O O O norpinonic O acid Criegee1 3 COOH O O O pinonic acid O a -pinene CH CHO O 3 + other O COOH products Criegee2 COOH pinic acid Mechanism

  11. pinonaldehyde

  12. Overall kinetic Mechanism • linked gas and particle phase rate expressions

  13. Particle Phase reactions cis-pinonaldhyde Gas phase reactions C=O C=O O O polymers particle

  14. Particle Phase reactions cis-pinonaldhyde C=O C=O O O Gas phase reactions particle polymers

  15. Particle Phase reactions cis-pinonaldhyde C=O C=O O O Gas phase reactions polymers

  16. Particle phase pinonaldehyde dimers from acida-pinene +O3 M Na+(ESI-QTOF Tolocka et al, 2003)

  17. Chemical System + NOx+ sunlight + ozone----> aerosols a-pinene

  18. data NO model O3 NO2 ppmV NO2 Time in hours EST 0.95 ppm a-pinene + 0. 44ppm NOx

  19. O O 3 mg/m Gas phase pinonaldehdye Time in hours EST

  20. 3 mg/m Measured particle mass vs. model Particle phase Particle phase data 3 mg/m model TSP model TSP Time in hours EST

  21. UNC outdoor chamber group

  22. Air Pollution in NorthernThailand

  23. Introduction to Environmental Physical Organic Chemistry • Environmental chemistry may be defined as "the study of sources, reactions, transport, effects, and fates of chemical species in water, soil, and air environments, and the effects of technology thereon.” Manahan, 1994

  24. Class objectives: • Highlight some important areas in environmental chemistry • present some of the common techniques that environmental chemists use to quantify process that occur in the environment • It is assumed that everyone has courses in organic and physical chemistry.

  25. Class objectives: • Partitioning is a thread that runs through the course • Linear free energy relationships will be used to help quantify equilibrium and kinetic processes

  26. Thermodynamics • ui = uo1 +RT ln pi/p*iL • fi = i Xipi*pure liquid • RT lnfi hx /fiopure liq = RT lnfi H2O/fiopure liqfihx = fi H2O • ln Kp = a 1/T+b

  27. Vapor pressure How to calculate boiling points

  28. Vapor pressure and Henry’s law sat P sat sat *    i K P V iL iw sat iaw iw C iw Solubility and activity coefficients Octanol-water partitioning coefficients

  29. Additional Principles • Organic Acid-bases and LFERs • diffusion • chemical spills and mass transfer • Organic reactions in the environment • Solid- liquid interactions • photochemistry

  30. Homework, quizzes, exams • To insure that most of us stay reasonably current with the lectures and readings, an option is to have 6-8 unannounced quizzes throughout the semester. • They will take ~10 minutes. The first quiz will be on Chapter 2 since we will not cover Chapter 2. Quizzes will count 10% of your grade.

  31. Another option is a set of short questions to be answered and handed in before most lectures (10% of grade)—your choice!

  32. There will be a homework problem set associated with each assigned chapter of the book. It is due a week after the completion of the book chapter. • These problem sets should take between 3 and 10 hrs. Answers will graded and returned to you as soon as possible. These will count for 25% of your grade.

  33. In addition, you are expected to work through the illustrative examples and problemswhich have answers in the test on your own. • Some of these could appear on exams • There will be two exams (70% of your grade) 25% homeworks, 5%???

  34. Learning • Read Chapter • Simple or short Homeworks • Lecture ??? • Long Homeworks • Exams

  35. Why the interest? There are more than 70,000 synthetic chemicals that are in daily use: solvents components of detergents dyes and varnishes additives in plastics and textiles chemicals used for construction antifouling agents herbicides, insecticides,fungicides

  36. Some examples of environmental chemicals Polynuclear Aromatic HC (PAHs) Dioxins Ketones PCBs CFCs DDT O3, NO2, aerosols, SO2

  37. PAHs Formed from small ethylene radicals “building blocks” produced when carbon based fuels are burned Sources are all types of burning in ChiangMai, Thailand:a) 2-stroke motorcycle engines b) cars- light diesels c) open burning d) barbecued meat??

  38. Combustion Formation of PAH Badger and Spotswood 1960

  39. PAHs Metabolized to epoxides which are carcinogenic; O PAH are indirect acting mutagens in bacterial mutagenicity tests (Ames-TA98+s9) methyl PAHs are often more biologically active than PAHs

  40. Carcinogenic tests with PAHs Professor Gernot Grimmer extracted different types of smoke particles He then took the extract and applied it to mouse skin and implanted it into rat lungs How did he obtain extracts? How did he fractionate his extracts??

  41. Extraction by soxhlet extraction starts with solvent (MeCl2) in a flask

  42. Extraction by soxhlet extraction starts with solvent (MeCl2) in a flask MeCl2

  43. The solvent is heated and starts to evaporate Heat

More Related