Bellwork 310 Week 10 Please turn your lab
Bellwork 3/10 * Week 10 Please turn your lab notebooks into TBG 1. What are the two general major categories/sources of air pollution? 2. Please include examples in your answers. Hint: Read page 526
Air Pollution Outdoor Air Pollution
Stationary and Mobile Sources of Air Pollution • Two Sources of Air Pollution 1. Stationary Sources: have a relatively fixed location • Point Sources: • Fugitive Sources: • Area Sources: 2. Mobile Sources: move from place to place while emitting pollutants • Ex) Airplanes
General Effects of Air Pollution • • • Visual quality of the environment Vegetation, Animals, Soil Water Quality Natural and Artificial Structures Human Heath
Human Health & Air Pollution
Primary and Secondary Pollutants, Natural and Human • Primary Pollutants – Those emitted directly into the air – Hydrocarbons, particulates, etc. • Secondary Pollutants – Produced through reactions between primary pollutants and normal atmospheric compounds – Ozone
Major Air Pollutants 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Sulfur Dioxide (acid rain) Nitrogen Dioxide / Nitrogen Oxide Carbon Monoxide Ozone and Other Photochemical Oxidants Volatile Organic Compounds Particulate Matter Hydrogen Sulfide Hydrogen Fluoride Hazardous Gases Lead
Outdoor Air Pollutants – Sulfur Dioxide (SO 2) • Properties: colorless gas with irritating odor • Effects: produces acid rain (H 2 SO 4), breathing difficulties, eutrophication due to sulfate formation, lichen and moss are indicators • Sources: burning high sulfur coal or oil, smelting or metals, paper manufacture • Class: sulfur oxides • EPA Standard: 0. 3 ppm (annual mean) • Combines with water and NH 4 to increase soil fertility
Outdoor Air Pollutants – Nitrogen Dioxide (NO 2) • Properties: reddish brown gas, formed as fuel burnt in car, strong oxidizing agent, forms Nitric acid in air • Effects: acid rain, lung and heart problems, decreased visibility (yellow haze), suppresses plant growth • Sources: fossil fuels combustion, power plants, forest fires, volcanoes, bacteria in soil • Class: Nitrogen oxides (NOx) • EPA Standard: 0. 053 ppm
Outdoor Air Pollutants – Carbon Monoxide (CO) • Properties: colorless, odorless, heavier than air, 0. 0036% of atmosphere • Effects: binds tighter to Hb than O 2 • Sources: incomplete combustion of fossil fuels. 60 - 95% from auto exhaust • Class: carbon oxides (CO 2, CO) • EPA Standard: 9 ppm • 5. 5 billion tons enter atmosphere/year
Outdoor Air Pollutants – Ozone (O 3) • Properties: colorless, unpleasant odor, major part of photochemical smog • Effects: lung irritant, damages plants, rubber, fabric, eyes, 0. 1 ppm can lower PSN by 50% • Sources: Created by sunlight acting on NOx and VOC , cars, industry, gas vapors, chemical solvents, fuel combustion products • Class: photochemical oxidants
Outdoor Air Pollutants – Suspended Particulate Matter (PM 10) • Properties: particles suspended in air (<10 um) • Effects: lung damage, mutagenic, carcinogenic, teratogenic • Sources: burning coal or diesel, volcanoes, factories, unpaved roads, plowing, lint, pollen, spores, burning fields • Class: SPM: dust, soot, asbestos, lead, PCBs, dioxins, pesticides • EPA Standard: 50 ug/m 3 (annual mean)
Size of Selected Particulates
Total Suspended Particulates (TSP) for several large countries
Outdoor Air Pollutants – VOCs (Volatile Organic Compounds) • Properties: organic compounds that evaporate easily, usually aromatic • Effects: eye and respiratory irritants; carcinogenic; decreased visibility due to brown haze; liver, CNS, or kidney damage; damages plants • Sources: evaporation of solvents or fuels, fossil fuels, plants (largest source), aerosols, paint thinners, dry cleaning • Class: HAPs (Hazardous Air Pollutants) • Concentrations indoors up to 1000 x outdoors • 600 million tons of CFCs
Outdoor Air Pollutants – Lead (Pb) • Properties: grayish metal • Effects: accumulates in tissue; affects kidneys, liver and nervous system (children most susceptible); mental retardation; possible carcinogen; 20% of inner city kids have [high] • Sources: particulates, smelters, batteries • Class: toxic or heavy metals • EPA Standard: 1. 5 ug/m 3 • 2 million tons enter atmosphere/year
US Emissions of Six Major Air Pollutants Note that there have been significant reductions.
Urban Air Pollution • Potential for Air Pollution Determined by: – Rate of emission – Downwind distance – Average wind speed – Elevation • Atmospheric Inversion: – Occurs when warmer air is found above cooler air and it poses a particular problem when there is a stagnant air mass
Factors that influence Air Pollution formation and intensity • Local climate (inversions, air pressure, temperature, humidity) • Topography (hills and mountains) • Population density • Amount of industry • Fuels used by population and industry for heating, manufacturing, transportation, power • Weather: rain, snow, wind • Buildings (slow wind speed) • Mass transit used • Economics
Questions 1. How would you define smog? 2. What are the two types of smog and how do they form? Hint: Read pages 540 -541
Smog • Smog – A mixture between smoke and fog that produces unhealthy urban air • Two Types – Sulfurous Smog / Industrial Smog / Fossil Fuels – Photochemical Smog / Sunlight & Pollutants
Formation of Industrial Smog
Formation of Industrial Smog Procedure 1. Carbon in coal or oil burned 2. Unburned carbon -> soot 3. Sulfur in oil and coal reacts with O 2 Chemical Reaction C + O 2 -> CO 2 2 C + O 2 -> CO C S + O 2 -> SO 2
Formation of Industrial Smog Procedure 4. Sulfur dioxide reacts with O 2 to form sulfur trioxide 5. Sulfur trioxide reacts with H 2 O 6. Sulfuric acid reacts with atmospheric ammonia to form brown, solid ammonium sulfate Chemical Reaction 2 SO 2 + O 2 -> 2 SO 3 + H 2 O -> H 2 SO 4 + 2 NH 3 -> (NH 4)2 SO 4
Formation of Photochemical Smog
Formation of Photochemical Smog Time Description 6 - 9 A. M. Morning commute increases NOx and VOCs N 2 + O 2 -> 2 NO NO + VOC -> NO 2 -UV-> NO + O 9 - 11 A. M As traffic decreases NOx and VOCs react 2 NO + O 2 -> 2 NO 2
Time Description 11 A. M. As sunlight becomes intense, NO 2 breaks down – 4 P. M. and Ozone increases NO 2 -UV-> NO + O O 2 + O -> O 3 Nitrogen dioxide also forms nitric acid 3 NO 2 + H 2 O -> 2 H 2 NO 3 + NO 11 A. M. Nitrogen dioxide also reacts with VOCs released – 4 P. M. by autos, industry, etc. NO 2 + VOCs -> 2 PANs Peroyacyl nitrates (toxic) 4 P. M. - As sun goes down the production of ozone halts sunset Net Result: NO + VOC + O 2 + UV -> O 3 + PAN
Pollution Control • Particulates • Automobiles • Sulfur Dioxide – Coal Gasification: converts coal to gas to remove sulfur – Scrubbing: gas desulfurization
Air Pollution: Legislation and Standards • Clean Air Act Amendments of 1990 – Comprehensive regulations enacted by U. S congress that address acid rain, toxic emissions, ozone depletion and automobile exhaust • Air Quality Standards – Attempt to control air pollution • Tougher Standards for PM 2. 5 and Ozone • Air Quality Index
Specific Air Pollution Treatment Technology • Traditional – Move factory to remote location – Build taller smokestack so wind blows pollution elsewhere • New – Biofiltration : vapors pumped through soil where microbes degrade – High-energy destruction: high-voltage electricity – Membrane separation: diffusion of organic vapors through membrane – Oxidation: High temperature combustor
Specific Air Pollution Treatment Technology Continued… • New continued… – Vapor phase carbon absorption: gases pumped through series of carbon filled canisters which absorb contaminants – Electrostatic precipitators: Electrostatically charged surfaces attracts particles – Sulfur removal: mix crushed limestone with fuel – Nitrogen oxide control: staged burners or catalytic converters – Hydrocarbon control: closed system to prevent release before treatment with afterburners – Hybrid, electric and hydrogen powered vehicles
Air Pollution Indoor Air Pollution
Pathways, Processes and Driving Forces • Chimney Effect (Stack Effect) – Process whereby warmer air rises in buildings to upper levels and is replaced in the lower portion of the building by outdoor air drawn through a variety of openings, such as windows doors or cracks in the foundation or walls
Sick Building Syndrome • A condition associated with an indoor environment that appears to be unhealthy • The symptoms people report cannot be traced to any one particular cause
Environmental Tobacco Smoke • Secondhand smoke • 2 sources – Smoke exhaled by smokers – Smoke emitted from burning tobacco • The most hazardous indoor pollutant
Questions Read a closer look 25. 1 (p 562 -3) 1. Please explain why radon is a problem? 2. Is radon a large hazard? If so why? If not, why? Hint: Read pages 540 -541
Radon Gas • Radon – Naturally occurring radioactive gas – Colorless, odorless, tasteless – Only identified through proper testing • Health hazard when leaked into homes • Exposure is associated with lung cancer
How Radon Enters Houses Please read page 574 and explain how radon enters houses.
Major Indoor Pollutants 1, 1, 1 Aerosol sprays Trichloroethane Dizziness, breathing irregularities Asbestos Pipe insulation, ceilings, floor tiles, oven mitts Lung Cancer and asbestosis Benzo-apyrene Tobacco smoke, woodstoves Lung Cancer Carbon Monoxide Faulty furnaces, cigarette smoke Headache, heartbeat irregularities, death, CO has 250 x affinity for Hb than O 2
Major Indoor Pollutants Continued… Chloroform Pulp and paper mills, water and wastewater plants Cancer Formaldehyde Paneling, particle board, Nausea, dizziness, furniture, carpeting, irritation of throat, adhesives eyes, and lungs Methylene chloride Paint strippers and thinner – persistent Nerve disorders, diabetes Nitrogen oxides Furnaces, stoves, fireplaces and vents Headaches, irritated lungs Paradichlorobenzene Air fresheners, mothballs Cancer
Major Indoor Pollutants Continued… Radon – 22 Soil and rock near house foundation, concrete Carpets, plastics, Lung cancer Tetrachlorethylene Dry-cleaning fluid Nerve disorders, damage to liver and kidneys, cancer Tobacco Smoke Cigarettes and other smoking sources Lung cancer and heart disease Organic Material Dust mites, fungal and algal spores, dust (human skin), animal dander, hair, carpet fibers, fur Allergies, coughs, sneezing, eye irritation, sore throats, difficulty breathing Styrene http: //www. metricmind. com/ac_honda/main. htm Kidney and liver damage
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