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Home sweet home . . . PowerPoint Presentation
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Home sweet home . . .

Home sweet home . . .

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Home sweet home . . .

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Presentation Transcript

  1. Home sweet home . . .

  2. Or is it????

  3. Breathing! Some basics

  4. Normal chemical composition of our atmosphere: (N2) 78% (O2) 21% Trace gases (water, argon, carbon dioxide, other pollutants) 1% What is in our atmosphere?

  5. Pollution terminology • Pollutant • Source • Effect

  6. Article: EPA Proposes New Ozone Standard • EPA = Environmental Protection Agency

  7. Pollution units Parts per thousand (ppt) Parts per million (ppm) Parts per billion (ppb)

  8. Smog and ozone form together • N2 + O2 2NO • 2NO + O2  2NO2 • NO2 + UV radiation  NO + O • O + O2  O3

  9. Primary pollutants come directly from a source • Mobile sources

  10. Mobile sources

  11. Stationary Sources • Power plants

  12. Refineries

  13. Secondary pollutants form in atmosphere as gases react • Smog, ground level ozone and acid rain

  14. Secondary pollutants form in atmosphere as gases react • Step two: 2NO + O2  2NO2 • NO2 is smog – a yellow brown gas • Causes lung and eye irritation, makes asthma, bronchitis and emphysema worse

  15. Ozone formation Step 3: NO2 + UV radiation  NO + O Step 4:O + O2  O3 Ozone slows photosynthesis, eye and lung irritant, makes asthma, emphysema, bronchitis worse

  16. Check out ozone formation • Texas Commission on Environmental Quality • EPA: National/Federal Regulatory agency • TCEQ: state regulatory agency • ozone animation Houston Clean Air Network Map

  17. AQI: set at 100 for each criterion pollutant level. Ozone 100 AQI = 85ppb

  18. Smog and ozone form together • N2 + O2 2NO • 2NO + O2  2NO2 • NO2 + UV radiation  NO + O • O + O2  O3 Ozone season: March- November Ozone daily formation: noon-early evening

  19. VOCs – a second route for O3 formation • Volatile Organic Compounds: • Methane (CH4) • Propane • Chlorofluorocarbons (CFC)

  20. VOCs can break O2 into free oxygen atoms (free radicals) • VOC + O2 VOC + 2O • O + O2 O3

  21. We're #? . . . .for the number of days exceeding allowable ground level ozone levels. American Lung Association State of the Air

  22. We're #? . . . .for the number of days exceeding allowable ground level ozone levels. American Lung Association State of the Air

  23. Measuring pollutants • parts per thousand = ppt • parts per million = ppm • Parts per billion = ppb • Parts per trillion = ppt (must know from context)

  24. Clean Air Act • Passed by Congress in 1970, updated in 1990, ‘93, 97, 2008. • Required EPA (Environmental Protection Agency) to identify criteria pollutants and to establish minimum standards: EPA came up with NAAQ’s

  25. National Ambient Air Quality Standards • Six criterion pollutants: NOx, SOx, O3, Pb, CO, particulates • Established minimum standards: 1hr and 8 hr • EPA is working to have greenhouse gases added by Congress to the NAAQs

  26. Houston’s special issues • 1/3 of all US petrochemicals pass through our refineries • Refineries separate crude oil into many different products from asphalt tar to gasoline to butane

  27. Refineries create carcinogenic air pollutants Benzene, toluene, ethylbenzene, xylenes

  28. So what is being done about this? - City monitoring

  29. 45 mobile monitoring stations

  30. State monitoring • Flexible permitting – each facility has total cap emissions limit, but flexibility in how they meet that limit. • TCEQ issues permits for emitting certain amount of pollutants • Facilities do “self reporting”

  31. Check your understanding! • What is the difference between a primary and a secondary air pollutant? • Give an example of a mobile source. • Give an example of a stationary source. • Which layer of the atmosphere are you in RIGHT NOW?!!!! • What is the normal chemical composition of our atmosphere?