Air Pollution Control

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Air Pollution Control

• Chapter 1
• Overview of Air Pollution

By Dr. Wipada Sanongraj
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Thailand Air Quality Standards
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??????????????????????? ???? ?.?. 2545
????????????????????????????????
?????????????????????????????????? 10 ?????? ????
PM10 ??????????????? (O3) ????????????????????????
??? (SO2) ????????????????????? (NO2)
???????????????????? (CO) ????????????????????????
?????
?????????????????????????? ?????????????????????
?????? ?????? ???????????? ????????? ???????
???????????????????????? ?????????????????????????
????????? ????????????????????????????????????????
?????? ??????????????????? ???????????????????????
???? ???????????????????????????????????????
?????????????? ???? ????????????????????? (SO2)
????????????????????? (NO2) ????????????????????
(CO) ?????????????????????????????
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1.1 Air Pollution Problem

• Air Pollution is an atmospheric condition in
  which substances are present at concentrations
  higher than their normal ambient level to produce
  significant effect on humans, animals,
  vegetation, or material (Seinfeld, 1986)

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1.1 Air Pollution Problem

• Substances can be natural or man-made compounds
  in gaseous, liquid, or solid phase that can
  airborne.
• Air pollution problem began since human started
  using fires.
• Becomes substantially serious during last 200
  years, when the world population are overgrowing
  and development of industrialization

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1.1 Air Pollution Problem

• In US, air pollutants are released into
  atmosphere 150 million metric tons per year.
• Worldwide, releases of air pollutants are 2
  billion metric tons per year.

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1.2 Types of Air Pollution Problem
I
II
III
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1.2 Types of Air Pollution Problem

• Type I includes
• indoor air pollution in house and commercial
  building
• local pollution around isolated factory, power
  plant, waste disposal site
• urban pollution resulting from urban sources

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1.2 Types of Air Pollution Problem

• Type II includes
• Regional air pollution
• Continental air pollution
• Such as transport of particulate matter from
  Mexico to USA

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1.2 Types of Air Pollution Problem

• Type III includes
• Hemisphere air pollution
• Global air pollution
• Such as global warming, ozone depletion

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1.3 Components of an Air Pollution Problems

• Each type of pollution has 3 major components
• Emission sources
• The atmosphere transport, diffusion,
  transformation, removal processes
• Receptors near the ground

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1.3 Components of an Air Pollution Problems

• Estimating or measuring emissions from a variety
  of a source requires
• Knowledge of the chemistry of combustion
• Engineering aspects of the equipment design and
  air pollutant control technology

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1.3 Components of an Air Pollution Problems

• Understanding characteristic of air pollutants
  requires
• Knowledge of the atmospheric chemistry
• Aerosol physics
• Atmospheric radiation

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1.3 Components of an Air Pollution Problems

• Understanding transport of air pollutants
  requires
• Knowledge of meteorology
• Environmental fluid mechanics
• Turbulent exchange and mixing process

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1.3 Components of an Air Pollution Problems

• Understanding chemical transformation and removal
  process requires
• Knowledge of atmospheric chemistry, cloud and
  precipitation

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Schematic of the various components of the air
pollution problem on a local/urban scale
Automatic control
Detector
Emission source
Source control
Atmosphere
Receptor
Humans Animals Plants Materials
Respond
Legislative action
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1.4 Sources of Air Pollution

• Urban and industrial sources
• Agricultural and other rural sources
• Natural emissions

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1.4.1 Urban and Industrial sources

• Power Generation
• Fossil-fuel power plants are major source
• Major gaseous pollutants are CO, CO2, SO2, NOx,
  and certain HCs and VOCs
• Nuclear power plants are much cleaner
• Occasional nuisance of fog formation and
  visibility reduction
• Accidental releases of radioactive substances

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1.4.1 Urban and Industrial sources

• Industrial facilities
• Mining, refining, manufacturing, smelting, pulp
  and paper, chemical, metallurgical,
  pharmaceutical, and others
• Smokestack emissions, fugitive emissions

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1.4.1 Urban and Industrial sources

• Transportation
• Automobiles, buses, trucks, airplanes, boats
• Emissions are estimated on per unit area basis
• Considering traffic density, speed, emissions per
  vehicle, and other variables
• Major pollutants produced are CO, CO2, NOx, SO2,
  HCs, and VOCs

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1.4.1 Urban and Industrial sources

• Process Emissions
• Furnaces and other processes used for heating
  homes, office, and commercial building,
  fireplaces, stoves, backyard barbecue grills, and
  open burning
• Emissions are estimated on per unit area basis
• Major pollutants produced are CO, CO2, NOx, SO2,
  HCs, VOCs, and particulate matter

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1.4.1 Urban and Industrial sources

• Waste disposal
• Landfills, incineration facilities, sewage
  treatment plants, backyard compost pits, and
  refuse dumps
• Major pollutants produced are CO, CO2, CH4, H2S,
  NH3, and particulate air pollution

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1.4.1 Urban and Industrial sources

• Construction activities
• Land clearing, demolition, digging, grinding,
  paving, painting
• Major pollutants produced are dust and other
  particulate matter, hydrocarbons, VOCs, CO, CO2
  and NOx

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1.4.2 Agricultural and other Rural Sources

• Dust Blowing
• Agricultural operations of tilling, and
  harvesting
• Emissions from tractors, harvesters and other
  machinery are not very significant

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1.4.2 Agricultural and other Rural Sources

• Slash burning
• Land clearing by burning of forests, straw, wild
  grass
• Emissions are a major source of smoke and haze in
  the countryside

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1.4.2 Agricultural and other Rural Sources

• Soil emissions
• Applications of fertilizers in cropland
• Sources of nitrogen oxides in the topmost soil
  layer

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1.4.2 Agricultural and other Rural Sources

• Pesticides
• Substances used to kill and harm pests
• Decaying wastes
• Release of ammonia, methane and noxious vapors
  from agricultural and animal waste

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1.4.3 Natural Sources

• Wind erosion
• Dust storms induce by wind erosion
• Dust particles consist mainly of SiO2 and trace
  of heavy metal

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1.4.3 Natural Sources

• Forest fires
• Large amount of smoke, CO, CO2, NOx, and HCs
• Leading to formation of secondary organic aerosol
  (SOA) and ozone

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1.4.3 Natural Sources

• Volcanic Eruption
• Huge amount of particulate matter, CO2, SO2, and
  other gases
• Global impact on climate change

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1.4.3 Natural Sources

• Biogenic emissions
• Emissions from forests and marshlands
• Major pollutants are HCs, such as terpenes and
  isoprenes, methane, ammonia, pollen, and spores

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1.4.3 Natural Sources

• Sea spray and evaporation
• Major sources of salt particles in the atmosphere
• Soil microbial process
• Include aerobic and anaerobic respiration of
  natural soils and vegetation resulting in the
  emissions of NO, CH4, H2S, and NH3
• Lightning
• Produces large amount of NO

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1.5 Air Pollutants

• Primary pollutants
• Emitted directly from sources and not undergoing
  any chemical or physical transformation
• Secondary pollutants
• Formed in the atmosphere as a result of
  photochemical reaction. Such as NO, NO2, O3, SOA,
  and oxygenated hydrocarbons

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1.5 Air Pollutants

• Another classification based on the state of the
  pollutant matter
• Gaseous air pollutants include all the gases in
  atmosphere
• Particulates include both solid and liquid
  particles that become airborne

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1.6 Concentration Unit

• commonly expressed in term of the volume of the
  species per unit volume of air (e.g., ppm by
  volume)
• Another measure for gaseous as well as
  particulates is the mass of species per unit
  volume of air (e.g., mg/m3)

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1.6 Concentration Unit

• Conversion between the volumetric conc.(Cvi,ppm)
  and the mass conc. (Cmi, mg/m3) refers to these
  equations
• Cvi (Ci/Ca)106 (ppm)
• Cmi Cimi106 (mg/m3)
• Where Ci defined as moles per unit volume of air
• mi denoted the mean molecular mass in grams per
  mole
• Ca is the molar conc. of air in mole per cubic
  meter

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1.6 Concentration Unit

• Cvi (Ci/Ca)106 (ppm)
• Cvi moles m3 of air 106
• m3 of air moles of air
• Cmi Cimi106 (mg/m3)
• Cmi mole gram 106
• m3 of air mole

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1.6 Concentration Unit

• Using ideal gas law for air
• PV nRT
• By definition
• Ca (n/V) P/RT
• Relationship between volumetric and mass
  concentrations
• Cvi (RT)Cmi/(Pmi)

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Table 1.2 Clean Atmospheric Concentrations
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1.7 Criteria Air Pollutants

• CO
• O3
• SO2
• NOx
• Pb
• PM10 and PM2.5
• HCs

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???????????????? (CO)
????????? (properties) ?????????????????? ?????
?? ?????????????????????????????????????????????
????????????????? ???? ????????????????????????
??? ?????? ???????????????????????????????????????
?????? ???????????????????????????????
??????????? (sources) ????????????????? ?
????????????????? ???????? ??????????????
????????????????????????????????? ??? ??????????
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Source of CO emitted to the atmosphere in USA
(www.epa.gov)
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?????????????????????? (health effects) reducing
oxygen delivery to the bodys organs tissues,
chest pain, heart failure, vision problem,
headache, dizzy, and nausea
????????????????????? (environmental effects)
contributes to the formation of smog
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?????? (Pb)
????????? (properties) ?????????????????????
???????????????? ?????????????????????????????????
??? ?????????????????? ?????????? ????????
??????????? (sources) ????????????????????????????
??? ??????????????????????????????????????????????
???????? ?????????????????????????????????????????
???????????????
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?????????????????????? (health effects)
????????????????????????????????
??????????????????? ??????????????? ?????
??????????????? ???????????????????
????????????????????????? ?? ?????????
???????????????????????????????????
?????????????? ???????????
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????????????????? (SO2)
????????? (properties) ??????? ????
??????????????? ?????????? ????????
??????????? (sources) ???????????????????
????????????? ???????????????????????????????????
??????? ?????????
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?????????????????????? (health effects)
??????????? ???????????????????
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??????????????? (NOX)
????????? (properties) ???????????????
??????????????????? NO2 ??????????????????????????
????????????????????????
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Sources of NOx in USA (http//www.epa.gov/air/urb
anair/nox/what.html)
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?????????????????????? (health effects)
??????????????????? VOC ???????????????????????
?????????? ????? ?????????????????????????????????
??????? ???????????????????
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????? (Ozone)
??????????????????????????????? 3 ????? (O3)
Good ozone
Bad ozone
??????????????????? ??????????????????????????????
? ??????????? ?????? ?????? natural photochemical
reactions
????????????????????
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?????????????????????? (health effects)
??????????????????? ??????????? ?? ??????????
???????????????????
????????????????????? (environmental effects)
??????????????????????????????????
??????????????????????????????????????????????????
???????????
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PM10
?????????????????????????????????????????? 10
??????
?????????????? PM10 direct emission of primary
particles such as dust from roads or elemental
carbon from wood combustion.
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Formation of primary gaseous emissions such as
sulfates formed from SO2 emissions from power
plants and nitrates formed from NOx emissions
from power plants, automobile, and combustion
sources
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?????????????????????? (health effects) cause
numerous health problems including heart and lung
diseases, aggravate respiratory conditions such
as asthma and bronchitis Fine particles have
been more clearly linked to the most serious
health effects than coarse particles.
??????????????????????????? (environmental
effects) Airborne particles also can impact
vegetation and ecosystems and can cause damage to
paints and building materials
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???????????? (Hydrocarbon)
Organic compounds consist only of carbon and
hydrogen.
Divided into 1) aliphatic 2) alicyclic 3)
aromatic
saturated unsaturated
Hydrogenation
Unsaturated
saturated
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hn
Hydrocarbons O2/O/O/free radicals
O3/NO2/PAN/aldehyde
?????????????????????? (health effects)
??????????????????? aromatic hydrocarbons
?????????????????????????????? ?? human
carcinogenic