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CE 3231 - Introduction to Environmental Engineering and Science. Readings for This Class: 5.5-5.6. O hio N orthern U niversity. Chemistry, Microbiology & Material Balance. Introduction. Water & Air Pollution. Env Risk Management. Introduction to Air Quality
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CE 3231 - Introduction to Environmental Engineering and Science Readings for This Class: 5.5-5.6 Ohio Northern University Chemistry, Microbiology & Material Balance Introduction Water & Air Pollution Env Risk Management Introduction to Air Quality Every breath we take is affected by air quality. This lecture serves to introduce students to topics within air pollution and control technologies. Additional topics will be explored with more depth in subsequent lectures.
Air Quality Topics Covered Include: Introduction (Air Quality I) Atmospheric dispersion modeling (Air Quality II) Air pollution control technologies: Cyclones (Air Quality III) Air pollution control technologies: Electrostatic Precipitators (Air Quality IV)
Introduction: Air Pollution is all around us • Indoor Air Pollution (home and work environment) • Local (near emission source) • Regional • “Smog” and “Photochemical Smog” • Global • Stratospheric Ozone Depletion • Global warming /climate change
Air Pollution Culprits • Those that hurt you immediately • Smog (VOCs, O3, NOx, SOx) • Particulate Matter • Those that hurt you long term • Ozone Depletion (The story of CFCs) • Green House Gasses
Introduction: London Smog incident of 1952 • Smog = smoke + fog • Adverse effects due to soot particles + acid fog droplets • Probably the most deadly air pollution event in human history • Lots of coal burning + stagnant weather (foggy) • 4000 deaths with elevated death rate lasted long after the event http://www.metoffice.gov.uk/education/secondary/students/smog.html
Introduction: National Ambient Air Quality Standards (NAAQS) (CO) (Pb) (NOx) (O3) (SOx)
APC: Smog (Effects) • Ozone • Severe eye, nose and throat irritants • Lung damage • Plant damage, including leaf discoloration and cell collapse • A factor causing forest losses • NO2 • Visibility reduction (brownish color)
Volatile Organic Carbon + NOx O3 APC: Smog
APC: SMOG (Formation of Ground Level Ozone) • NO2 and O3 relationships • NO2 + uv NO + O • O + O2 O3 • NO + O3 NO2+ O2 • Formation of OH radical • O3 + uv O2 + O • O + H2O 2OH . • VOC oxidation and NO2 relationship • VOC + OH . + O2 RO2. + H2O • RO2. + NO NO2 + RO.
APC: Sources of NOx Thousand tons / year
APC: Sources of VOC Thousand tons / year
APC: Average Emission of a Typical Car on the Road in 2002 FHWA-HEP-05-045
APC: Effects of PM PM2.5 (<2.5 mm, respirable) and PM10 (<10 mm, thoracic)
APC: Effects of PM • Health Effects • Asthma • Lung cancer • Cardiovascular issues • Premature death • Visibility Detailed damage mechanismunclear.
APC: PM Sources Sources: dust, combustion
APC: Upper level ozone…a good thing Formation: O2+UV photon O + O O + O2 + M O3 + M Both reactions are fast Destruction:O3+UV photon O2 +O O+O3 2O2 Second reaction is slow.O3 life time ~ 1-10 years. An orbit of retrieved GOME ozone profiles on October 22, 1997 overpass Indonesia in the tropics. The red line shows the NCEP tropopause.
APC: Ozone Depletion Mechanism…a bad thing • CFCs (Chlorofluorocarbon) have shown to be the major cause of ozone depletion. • They are non-reactive in the troposphere due to lack of UV • They gradually fill the troposphere and diffuse into the stratosphere Step1: Photolysis (splitting by sunlight) of CFC’s in the stratosphere Step2: Catalytic destruction of ozone Net:
APC: Largest ozone hole – September 2006 • From September 21-30, 2006 the average area of the ozone hold was the largest ever observed. 11.4 million square miles • (Area of USA: 3.5 million square miles) http://www.nasa.gov/vision/earth/lookingatearth/ozone_record.html
APC: Green House gasses and recent surface temperature variations • Surface temperatures have shown significant fluctuation over the last 1000 years. • Temperatures rose abruptly over the last century • The cause of these changes is still debated although it can be captured reproducibly in the most sophisticated models.
APC: Green House Gasses (Global warming is only the beginning…) • Sea level increase
APC: The Kyoto Protocol • UN treaty entered into enforce February 2005 • Developed countries to reduce their green house emission by an average of 5% below their 1990 level. • EU: 8% • US: 7% • Japan: 6% • United States signed the protocol but did not ratify the treaty
APC: Participation in the Kyoto Protocol Participation in the Kyoto Protocol: dark green indicates countries that have signed and ratified the treaty, yellow indicates those that have signed and hope to ratify it, and red indicates those that have signed but not ratified it.