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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 Introduction Chemistry, Microbiology & Material Balance 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.
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Lecture 26 Introduction to Air Quality (Air Quality I)
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DO Sag Curve Modeling
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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)
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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
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Air Pollution Culprits Those that hurt you immediately – Smog (VOCs, O 3, NO x, SO x ) – Particulate Matter Those that hurt you long term – Ozone Depletion (The story of CFCs) – Green House Gasses
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Introduction: London Smog incident of 1952 Smog = smoke + fog Adverse effects due to soot particles + acid fog droplets http://www.metoffice.gov.uk/education/secondary/students/smog.html 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
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Introduction: National Ambient Air Quality Standards (NAAQS) (CO) (Pb) (NOx) (SOx) (O 3 )
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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 NO 2 – Visibility reduction (brownish color)
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Volatile Organic Carbon + NO x O 3 APC: Smog
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APC: SMOG (Formation of Ground Level Ozone) NO 2 and O 3 relationships NO 2 + uv NO + O O + O 2 O 3 NO + O 3 NO 2 + O 2 Formation of OH radical O 3 + uv O 2 + O O + H 2 O 2OH. VOC oxidation and NO2 relationship VOC + OH. + O 2 RO 2. + H 2 O RO 2. + NO NO 2 + RO.
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APC: Sources of NO x Thousand tons / year
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APC: Sources of VOC Thousand tons / year
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APC: Average Emission of a Typical Car on the Road in 2002 FHWA-HEP-05-045
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APC: Car vs. Truck Emissions
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APC: Effects of PM PM 2.5 (<2.5 m, respirable) and PM 10 (<10 m, thoracic)
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APC: Effects of PM Health Effects – Asthma – Lung cancer – Cardiovascular issues – Premature death Visibility Detailed damage mechanism unclear.
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APC: PM Sources Sources: dust, combustion
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APC: Upper level ozone…a good thing An orbit of retrieved GOME ozone profiles on October 22, 1997 overpass Indonesia in the tropics. The red line shows the NCEP tropopause. O 2 +UV photon O + O O + O 2 + M O 3 + M Both reactions are fast Formation: Destruction: O 3 +UV photon O 2 +O O+O 3 2O 2 Second reaction is slow. O 3 life time ~ 1-10 years.
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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 Net: Step1: Photolysis (splitting by sunlight) of CFC’s in the stratosphere Step2: Catalytic destruction of ozone
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APC: However …
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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
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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.
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APC: Green House Gasses (CO2 as a Green House Gas)
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The Greenhouse Effect
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APC: Green House Gasses (Global warming is only the beginning…) Sea level increase
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APC: Green House Gases (Extreme Weather)
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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
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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.
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