AIR QUALITY AND POLLUTION (TKA 3301) LECTURE NOTES 12- Global Air P Problem

8/9/2019 AIR QUALITY AND POLLUTION (TKA 3301) LECTURE NOTES 12- Global Air P Problem

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TKA 3301:TKA 3301:

Global Air Pollution ProblemsGlobal Air Pollution Problems

Dr. Marzuki Hj. IsmailDr. Marzuki Hj. Ismail

Jabatan Sains KejuruteraanJabatan Sains Kejuruteraan


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Topics CoveredTopics Covered

1.1. HazeHaze

2.2. Ozone Layer DepletionOzone Layer Depletion

3.3. Acid RainAcid Rain

4.4. Global WarmingGlobal Warming


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TKA 3301:TKA 3301:Global Air Pollution ProblemsGlobal Air Pollution Problems

HazeHaze


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1. HAZE1. HAZE

1.11.1 What is haze?What is haze?

A kind of air pollution caused by the presenceA kind of air pollution caused by the presenceof a large number ofof a large number of fine particlesfine particles suspendedsuspended

in the atmosphere. These particles absorbin the atmosphere. These particles absorb

and scatter light, in the processand scatter light, in the process reducereduce

visibilityvisibility and render the air anand render the air an opalescent oropalescent or

hazy appearancehazy appearance..


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1. Haze (Contd)1. Haze (Contd)

1.21.2 Haze, fog or mistHaze, fog or mist ARE YOU CONFUSED?ARE YOU CONFUSED?

Haze: due to presence of suspension ofHaze: due to presence of suspension of dry and fine particulatesdry and fine particulates..

Relative humidity is normally < 95%.Relative humidity is normally < 95%.

Mist: due to presence ofMist: due to presence of water dropletswater droplets suspended in the air.suspended in the air.Relative humidity is normally > 95%.Relative humidity is normally > 95%.

Fog: due to presence ofFog: due to presence of water dropletswater droplets suspended in the air.suspended in the air.

Relative humidity is normally > 97%.Relative humidity is normally > 97%.

All of the above phenomena causeAll of the above phenomena cause reduced visibilityreduced visibility, but in the, but in the

Tropics, a mist or fog disappears a few hours after sunrise. As theTropics, a mist or fog disappears a few hours after sunrise. As the

ground heats up the water droplets evaporate. However, haze doesground heats up the water droplets evaporate. However, haze does

not disappear as a result of the warming up of the earths surface bynot disappear as a result of the warming up of the earths surface by

the sun. haze maythe sun. haze may persistpersist throughout the day and last for severalthroughout the day and last for several

days.days.


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1.31.3 Conditions favoring the occurrence ofConditions favoring the occurrence of

haze:haze:Adverse meteorological conditionsAdverse meteorological conditions

Prolonged dry weatherProlonged dry weather

Very light windsVery light winds

Stable atmosphere (presence of inversionStable atmosphere (presence of inversion

layer)layer)

High particulate emissionHigh particulate emission


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1.41.4 Sources of haze:Sources of haze:

L

ocal sourcesL

ocal sources Open burning (household refuse, disposal sites)Open burning (household refuse, disposal sites)

Biomass burning/forest firesBiomass burning/forest fires

Vehicular emission (diesel; 2 stroke engines)Vehicular emission (diesel; 2 stroke engines)

Industrial emissionIndustrial emission

External sourcesExternal sources

Biomass burning/forest firesBiomass burning/forest fires


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1.51.5 Impact of haze on the economy:Impact of haze on the economy:

The haze that hit the ASEAN region in 1997The haze that hit the ASEAN region in 1997 1998 has1998 has

been particularly severe that the UNEP labeled the blazebeen particularly severe that the UNEP labeled the blaze

among the most damaging in recorded history.among the most damaging in recorded history.

The total economic losses in terms of agricultureThe total economic losses in terms of agriculture

production, destruction of forest lands, health,production, destruction of forest lands, health,transportation, tourism, and other economic activitiestransportation, tourism, and other economic activities

have been estimated at $ 9.3 billion.have been estimated at $ 9.3 billion.


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1.61.6 Impact of haze on earth:Impact of haze on earth:

Short term: nose, throat & eye irritation; upperShort term: nose, throat & eye irritation; upper

respiratory infections (bronchitis & pneumonia);respiratory infections (bronchitis & pneumonia);

headaches; nausea; allergic reactions; aggravatesheadaches; nausea; allergic reactions; aggravates

conditions of asthmatic patients.conditions of asthmatic patients.

Long term: chronic lung disease; lung cancer;Long term: chronic lung disease; lung cancer;heart disease; damage to CNS, kidney and liver;heart disease; damage to CNS, kidney and liver;

aggravates medical conditions of the aged.aggravates medical conditions of the aged.


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1.71.7 What ASEANs been doing to tackle theWhat ASEANs been doing to tackle the

problem?problem?

ASEAN has formulated theASEAN has formulated the Regional Haze Action Plan (RHAP)Regional Haze Action Plan (RHAP) toto

address its transboundary haze pollution problem.address its transboundary haze pollution problem. The RHAP has three major components:The RHAP has three major components: prevention, mitigationprevention, mitigation

and monitoringand monitoring. Different countries have been designated to. Different countries have been designated to

spearhead the activities that fall under each of the three RHAPspearhead the activities that fall under each of the three RHAP

components.components.

Malaysia takes the lead in prevention, Indonesia in mitigation, &Malaysia takes the lead in prevention, Indonesia in mitigation, &Singapore in monitoring of fires and haze. All member countriesSingapore in monitoring of fires and haze. All member countries

also undertake the nationalalso undertake the national--level actions that relate to the threelevel actions that relate to the three

RHAP components.RHAP components.

Malaysia has formulated her ownMalaysia has formulated her own National Haze Action PlanNational Haze Action Plan..


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Ozone Layer DepletionOzone Layer Depletion


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2. OZONE LAYER DEPLETION2. OZONE LAYER DEPLETION

2.12.1 Formation and destruction of ozoneFormation and destruction of ozone

Ozone (OOzone (O33) found both in) found both in tropospheretroposphere andand stratospherestratosphere..

OO22 formation:formation:

OO22 ++ hvhv ((


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2. Ozone Layer Depletion2. Ozone Layer Depletion

(Contd)(Contd) OO22 absorbs radiation of wavelength (absorbs radiation of wavelength () ~ 200nm. O) ~ 200nm. O33 absorbs in theabsorbs in the

range of 230 to 320 nm and converts it back to Orange of 230 to 320 nm and converts it back to O33..

Everyday OEveryday O22 is continually beingis continually being changedchanged to Oto O33 and Oand O33 is likewiseis likewiseconvertedconverted back to Oback to O22..

It is not completely correct to say natural process is OIt is not completely correct to say natural process is O22OO33 and thatand that

air pollution has destroyed ozone.air pollution has destroyed ozone.

What some air pollutants do is to speed up the rate of loss of OWhat some air pollutants do is to speed up the rate of loss of O33 soso

that itsthat its steady state concentrationsteady state concentration declines.declines.


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(Contd)(Contd)2.22.2 The ozone layerThe ozone layer

-- The term ozone layer isThe term ozone layer is misleadingmisleading no distinct region ofno distinct region of

atmosphere in which Oatmosphere in which O33

is a major atmospheric constituent.is a major atmospheric constituent.

-- Main componentsMain components of atmosphere in the stratosphere are still Nof atmosphere in the stratosphere are still N22

(78%), O(78%), O22 (21%), and Ar (1%).(21%), and Ar (1%).

-- OO33 concentration isconcentration is very smallvery small, even in the stratosphere. Maximum, even in the stratosphere. Maximum

concentration is about 100 ppmv.concentration is about 100 ppmv.

-- If all atmospheric OIf all atmospheric O33 is compressed at STP, Ois compressed at STP, O33 layer ~ 3 mm thick.layer ~ 3 mm thick.


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(Contd)(Contd)2.32.3 Chlorofluorocarbons (CFCs)Chlorofluorocarbons (CFCs)

CFCs have been manufactured since theCFCs have been manufactured since the 1930s.1930s.

CFCCFC--12 (CF12 (CF22ClCl22) was introduced as the) was introduced as the refrigerantrefrigerant i.e. operatingi.e. operating

liquid (gaseous at room temperature, easily compressible, boilingliquid (gaseous at room temperature, easily compressible, boiling

point a little below 0point a little below 0 ooC) in refrigerators replacing the highly toxicC) in refrigerators replacing the highly toxic

SOSO22 and NHand NH33..

CFCs are alsoCFCs are also nontoxicnontoxic andand nonflammable.nonflammable.

other uses of CFCs:other uses of CFCs: blowing agentsblowing agents for foam industry andfor foam industry and

propellantspropellants for aerosol sprays (mainly CFCfor aerosol sprays (mainly CFC--113, CF113, CF22ClCFClClCFCl22););

refrigerantrefrigerant for mobile air conditioners (automobiles).for mobile air conditioners (automobiles).


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(Contd)(Contd) CFCs have longCFCs have long atmospheric lifetimesatmospheric lifetimes andand ozone depletion potentialozone depletion potential

(ODP) as well as(ODP) as well as halocarbon global warming potentialhalocarbon global warming potential (HGWP).(HGWP).

ODP is the propensity of the substance toODP is the propensity of the substance to destroy stratosphericdestroy stratospheric

ozoneozone..

e.g.: CFCe.g.: CFC--11 (CFCl11 (CFCl33): lifetime = 60 years; ODP = 1.0, HGWP = 3.2;): lifetime = 60 years; ODP = 1.0, HGWP = 3.2;

CFCCFC--12 (CF12 (CF22ClCl22): 195, 0.95, and 3.1; CFC): 195, 0.95, and 3.1; CFC--113 (CF113 (CF22ClCFClClCFCl22): 90, 0.8,): 90, 0.8,

(HWDP(HWDP not available).not available).

CFCs alternatives should beCFCs alternatives should be ozone friendlyozone friendly as well as not act asas well as not act as

green house gasesgreen house gases..


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(Contd)(Contd)2.4.2.4. How is ozone layer destroyed?How is ozone layer destroyed?

Reactions (e.g. CFCReactions (e.g. CFC--12, i.e. CF12, i.e. CF22ClCl22):):

CFCF22

ClCl22

++ hvhv ((


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(Contd)(Contd)2.52.5 Why do CFCs have long atmospheric lifetimes?Why do CFCs have long atmospheric lifetimes?

CFCs areCFCs are long lived pollutantslong lived pollutants; some > 100 years.; some > 100 years.

They are almostThey are almost completely inertcompletely inert in the troposphere (< 15km) andin the troposphere (< 15km) andonly decompose throughonly decompose through photochemical reactionsphotochemical reactions once they reachonce they reach

the stratosphere (15km


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(Contd)(Contd)2.6.2.6. Effects of ozone depletionEffects of ozone depletion

Greater penetration of highly energetic short wavedGreater penetration of highly energetic short waved ultraviolet sunlightultraviolet sunlight

radiationradiation to the earths surface:to the earths surface:

Change of the climate.Change of the climate. Lowering of stratosphere; lowering the altitude of the tropopause.Lowering of stratosphere; lowering the altitude of the tropopause.

Biological effectsBiological effects

Less efficient filtering of radiation in the range 290Less efficient filtering of radiation in the range 290 330 nm i.e. UV330 nm i.e. UV--B. This highB. This high

energy radiation will have adverse effects on planktons, plants, animals, humansenergy radiation will have adverse effects on planktons, plants, animals, humans

(skin cancer; photochemical reaction in DNA).(skin cancer; photochemical reaction in DNA).


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(Contd)(Contd)2.7.2.7. International efforts to arrest ozone layer depletionInternational efforts to arrest ozone layer depletion TheThe

Montreal Protocol on substance that deplete the ozone layerMontreal Protocol on substance that deplete the ozone layer

(1987)(1987)

Complete phase out ofComplete phase out of hard CFCshard CFCs those with high ODP (such asthose with high ODP (such as

CFCCFC--11; CFC11; CFC--12). Developing countries are allowed a 1012). Developing countries are allowed a 10--year graceyear grace

for their phase out.for their phase out.

The pressure from the demands under the Protocol has spurredThe pressure from the demands under the Protocol has spurred

research into findingresearch into finding replacement for CFCsreplacement for CFCs. Today, several CFC. Today, several CFCalternatives should: be reactive in the lower atmosphere; containalternatives should: be reactive in the lower atmosphere; contain

less/no chlorine; have desirable properties in terms of volatility, lowless/no chlorine; have desirable properties in terms of volatility, low

flammability and low toxicity.flammability and low toxicity.


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Acid RainAcid Rain


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Contents

Contents

DefinitionDefinition

CausesCauses

FormationFormationAffected AreasAffected Areas

EffectsEffects

Preventive MeasuresPreventive Measures


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Definition of Acid RainDefinition of Acid Rain Precipitation that has a pH of less than that of natural rainwaterPrecipitation that has a pH of less than that of natural rainwater

(which is about 5.6 due to dissolved carbon dioxide).(which is about 5.6 due to dissolved carbon dioxide).

It is formed when sulphur dioxides and nitrogen oxides, as gasesIt is formed when sulphur dioxides and nitrogen oxides, as gases

or fine particles in the atmosphere, combine with water vapouror fine particles in the atmosphere, combine with water vapourand precipitate as sulphuric acid or nitric acid in rain, snow, orand precipitate as sulphuric acid or nitric acid in rain, snow, or

fog.fog.


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Natural Acidity of RainwaterNatural Acidity of Rainwater

Pure water has a pH of 7.0 (neutral);Pure water has a pH of 7.0 (neutral);

However, natural, unpolluted rainwater actually has a pH ofHowever, natural, unpolluted rainwater actually has a pH ofabout 5.6 (acidic)about 5.6 (acidic)

The acidity of rainwater comes from the natural presence ofThe acidity of rainwater comes from the natural presence of

three substances (COthree substances (CO22, NO, and SO, NO, and SO22) found in the troposphere.) found in the troposphere. COCO22 is present in the greatest concentration and thereforeis present in the greatest concentration and therefore

contributes the most to the natural acidity of rainwater.contributes the most to the natural acidity of rainwater.

Gas Natural Sources Concentration

Carbon dioxideCO2

Decomposition 375 ppm

Nitric oxide

NOElectric discharge 0.01 ppm

Sulfur dioxide

SO2

Volcanic gases 0-0.01 ppm


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Natural RainwaterNatural Rainwater

Carbon dioxide reacts with water to form carbonic acid (Eqn.1).Carbon dioxide reacts with water to form carbonic acid (Eqn.1).

Carbonic acid then dissociates to give the hydrogen ion (HCarbonic acid then dissociates to give the hydrogen ion (H++) and the) and thehydrogen carbonate ion (HCOhydrogen carbonate ion (HCO33--) (Eqn. 2).) (Eqn. 2).

The ability of HThe ability of H22COCO33 to deliver Hto deliver H++ is what classifies this molecule as an acid,is what classifies this molecule as an acid,

thus lowering the pH of a solution.thus lowering the pH of a solution.


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Formation of Acid RainFormation of Acid Rain


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When water vapor condenses, or as the rain falls, they dissolve in the water toWhen water vapor condenses, or as the rain falls, they dissolve in the water toform Hform H22SOSO44 and HNOand HNO33..

Nitric oxide (NO), is formed during lightning storms by the reaction ofNitric oxide (NO), is formed during lightning storms by the reaction of

nitrogen and oxygen (Eqn. 3).nitrogen and oxygen (Eqn. 3). In air, NO is oxidized NOIn air, NO is oxidized NO22 (Eqn. 4), which in turn reacts with water to give(Eqn. 4), which in turn reacts with water to give

nitric acid (HNO3) (Eqn. 5).nitric acid (HNO3) (Eqn. 5).


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When water vapor condenses, or as the rain falls, they dissolve in the water toWhen water vapor condenses, or as the rain falls, they dissolve in the water toform Hform H22SOSO44 and HNOand HNO33..

Nitric oxide (NO), is formed during lightning storms by the reaction ofNitric oxide (NO), is formed during lightning storms by the reaction of

nitrogen and oxygen (Eqn. 3).nitrogen and oxygen (Eqn. 3). In air, NO is oxidized NOIn air, NO is oxidized NO22 (Eqn. 4), which in turn reacts with water to give(Eqn. 4), which in turn reacts with water to give

nitric acid (HNOnitric acid (HNO33) (Eqn. 5).) (Eqn. 5).


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Causes of Acid RainCauses of Acid Rain

The principal cause of acid rain is from humanThe principal cause of acid rain is from human

sourcessources

Industrial factories, powerIndustrial factories, power--generating plants andgenerating plants andvehiclesvehicles

Sulphur dioxide and oxides of nitrogen are releasedSulphur dioxide and oxides of nitrogen are releasedduring the fuel burning process (i.e. combustion)during the fuel burning process (i.e. combustion)

MSN Encarta


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Affected AreasAffected Areas

CanadaCanadaAcid rain is a problem in CanadaAcid rain is a problem in Canada

Water and soil systems lack natural alkalinity such asWater and soil systems lack natural alkalinity such as

lime baselime base Cannot neutralize acidCannot neutralize acid

Canada consists of susceptible hard rock such asCanada consists of susceptible hard rock such asgranitegranite

Do not have the capacity to effectively neutralize acid rainDo not have the capacity to effectively neutralize acid rain


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Affected AreasAffected Areas

Industrial acid rain is a substantial problem in China,Industrial acid rain is a substantial problem in China,Eastern Europe and Russia and areas downEastern Europe and Russia and areas down--wind fromwind fromthem.them.

Acid rain from power plants in the Midwest UnitedAcid rain from power plants in the Midwest UnitedStates has also harmed the forests of upstate New YorkStates has also harmed the forests of upstate New Yorkand New England.and New England.

This shows that the effects of acid rain can spread overThis shows that the effects of acid rain can spread over

a large area, far from the source of the pollutiona large area, far from the source of the pollution


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Effects of Acid RainEffects of Acid Rain

Harmful to aquatic lifeHarmful to aquatic life

Increased acidity in water bodiesIncreased acidity in water bodies

Stops eggs of certain organisms (e.g. fish) to stopStops eggs of certain organisms (e.g. fish) to stophatchinghatching

Changes population ratiosChanges population ratios

Affects the ecosystemAffects the ecosystem


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Harmful to vegetationHarmful to vegetation Increased acidity in soilIncreased acidity in soil

Leeches nutrients from soil, slowing plant growthLeeches nutrients from soil, slowing plant growth

Leeches toxins from soil, poisoning plantsLeeches toxins from soil, poisoning plants

Creates brown spots in leaves of trees, impedingCreates brown spots in leaves of trees, impedingphotosynthesisphotosynthesis

Allows organisms to infect through broken leavesAllows organisms to infect through broken leaves


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MSN Encarta

http://abacus.bates.edu/~ganderso/biology/bio270/clover_leaf_burns_pH2_30d.gif


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Accelerates weathering in metalAccelerates weathering in metal

and stone structuresand stone structures

Eg. Parthenon in Athens, Greece;Eg. Parthenon in Athens, Greece;Taj Mahal in Agra, IndiaTaj Mahal in Agra, India

http://www.lauraknauth.com/photos/france/thinker.jpgMSN Encarta


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Affects human healthAffects human health

Respiratory problems, asthma, dry coughs, headaches andRespiratory problems, asthma, dry coughs, headaches and

throat irritationsthroat irritations

Leeching of toxins from the soil by acid rain can be absorbedLeeching of toxins from the soil by acid rain can be absorbedby plants and animals. When consumed, these toxins affectby plants and animals. When consumed, these toxins affect

humans severely.humans severely.

Brain damage, kidney problems, and Alzheimer's disease hasBrain damage, kidney problems, and Alzheimer's disease has

been linked to people eating "toxic" animals/plants.been linked to people eating "toxic" animals/plants.


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Reduce amount of sulphur dioxide and oxides ofReduce amount of sulphur dioxide and oxides ofnitrogen released into the atomospherenitrogen released into the atomosphere Use less energy (hence less fuel burnt)Use less energy (hence less fuel burnt)

Use cleaner fuelsUse cleaner fuels

Remove oxides of sulphur and oxides of nitrogenRemove oxides of sulphur and oxides of nitrogenbefore releasingbefore releasing Flue gas desulphurizationFlue gas desulphurization

Catalytic ConvertersCatalytic Converters


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Use cleaner fuelsUse cleaner fuels

Coal that contains less sulphurCoal that contains less sulphur

"Washing" the coal to reduce sulphur content"Washing" the coal to reduce sulphur content

Natural GasNatural Gas


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Flue Gas Desulphurisation (FGD)Flue Gas Desulphurisation (FGD)

Removes sulphur dioxide from flue gas (waste gases)Removes sulphur dioxide from flue gas (waste gases)

Consists of a wet scrubber and a reaction tower equippedConsists of a wet scrubber and a reaction tower equipped

with a fan that extracts hot smoky stack gases from a powerwith a fan that extracts hot smoky stack gases from a powerplant into the towerplant into the tower

Lime or limestone (calcium carbonate) in slurry form isLime or limestone (calcium carbonate) in slurry form is

injected into the tower to mix with the stack gases and reactsinjected into the tower to mix with the stack gases and reacts

with the sulphur dioxide presentwith the sulphur dioxide present


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(continued)(continued)

Produces pHProduces pH--neutral calciumneutral calciumsulphate that is physicallysulphate that is physically

removed from the scrubberremoved from the scrubber

Sulphates can be used forSulphates can be used forindustrial purposesindustrial purposes

Scrubber at workMSN Encarta


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Use other sources of electricity (i.e. nuclearUse other sources of electricity (i.e. nuclear

power, hydropower, hydro--electricity, wind energy,electricity, wind energy,geothermal energy, and solar energy)geothermal energy, and solar energy)

Issue of costIssue of cost

http://upload.wikimedia.org/wikipedia/commons/4/4e/Nuclear_Power_Plant_Cattenom.jpg


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Reducing the effects of Acid RainReducing the effects of Acid Rain

LimingLiming

Powdered limestone/limewater addedPowdered limestone/limewater addedto water and soil to neutralize acidto water and soil to neutralize acid

Used extensively in Norway andUsed extensively in Norway andSwedenSweden

Expensive, shortExpensive, short--term remedyterm remedy


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Problem ScenarioProblem Scenario

Suppose you worked in the government. ASuppose you worked in the government. A

company wants to set up a factory in yourcompany wants to set up a factory in yourcountry. It would bring jobs, but it would alsocountry. It would bring jobs, but it would also

bring about pollution, which would lead to acidbring about pollution, which would lead to acid

rain. Would you allow it? Justify your answer.rain. Would you allow it? Justify your answer.


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Acidic particles and vapours are deposited via two

processes - wet and dry deposition.

Wet deposition is acid rain, the process by which acids with

a pH normally below 5.6 are removed from the atmosphere

in rain, snow, sleet or hail.

Dry deposition takes place when particles such as fly ash,

sulphates, nitrates, and gases (such as SO2 and NO), aredeposited on, or absorbed onto, surfaces.

The gases can then be converted into acids when they

contact water.

[[ continued: ]]


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Global Warming (GHG)Global Warming (GHG)


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Causes of Global WarmingCauses of Global Warming

Several GHG responsible for warming, andSeveral GHG responsible for warming, and

humans emit them in a variety of wayshumans emit them in a variety of ways

Combustion of fossil fuels in cars, factories andCombustion of fossil fuels in cars, factories andelectricity productionelectricity production

The gas responsible for the most warmingThe gas responsible for the most warming -- COCO22 To understand the effects of all GHG together,To understand the effects of all GHG together,

scientists talk in terms of the equivalent amountscientists talk in terms of the equivalent amount

of CO2of CO2


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GasesGases

Greenhouse GasesGreenhouse Gases

Carbon dioxide; COCarbon dioxide; CO22 Water; HWater; H22OO

CFCsCFCs

Nitrous Oxide; NNitrous Oxide; N22OO

Methane; CHMethane; CH44

NOT Greenhouse GasesNOT Greenhouse Gases

Nitrogen; NNitrogen; N22 Oxygen; OOxygen; O22 Argon; ArArgon; Ar


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Different Types ofElectromagnetic Radiation DoDifferent Types ofElectromagnetic Radiation Do

Different Things to MoleculeDifferent Things to Molecule


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For a bending or stretching motion toFor a bending or stretching motion to

absorb IR radiation; it must change theabsorb IR radiation; it must change thedipole moment of the moleculedipole moment of the molecule

+ --

Symmetric Stretch;

IR Inactive

Antisymmetric Stretch;

IR Active

+ -- - + -


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Infrared Spectrum ofCOInfrared Spectrum ofCO22


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Infrared Spectrum of Water (HInfrared Spectrum of Water (H22O) VaporO) Vapor


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Greenhouse Gas RequirementsGreenhouse Gas Requirements

Minimum of 2 atoms needed for stretchingMinimum of 2 atoms needed for stretching

bondsbonds

Two atoms must be different in order for vibrationTwo atoms must be different in order for vibrationto change the dipole moment of moleculeto change the dipole moment of molecule

Minimum of 3 atoms needed to bend a moleculeMinimum of 3 atoms needed to bend a molecule


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Why Argon, Ar, Can Not Be aWhy Argon, Ar, Can Not Be a

Greenhouse GasGreenhouse Gas

1.1. Argon is in atomic form. Thus, there is noArgon is in atomic form. Thus, there is no

bond to another atom. So it cant absorb IRbond to another atom. So it cant absorb IRto stretch a bond it doesnt have.to stretch a bond it doesnt have.

2.2. Argon cant absorb IR to bend a moleculeArgon cant absorb IR to bend a molecule

since a minimum of 3 atoms is needed and itsince a minimum of 3 atoms is needed and it

has only 1 atom.has only 1 atom.


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Global Warming PotentialGlobal Warming Potential Represents the Relative Contribution aRepresents the Relative Contribution a

Molecule Has in Global WarmingMolecule Has in Global Warming

1.1. HowLong a Molecule in the Troposphere/ IsHowLong a Molecule in the Troposphere/ Is

There a Way to Remove Molecule FromThere a Way to Remove Molecule FromTroposphere?Troposphere?

2.2. Does the Molecule Absorb in the WindowDoes the Molecule Absorb in the Window

Region?Region?3.3. Amount of Molecule in the TroposphereAmount of Molecule in the Troposphere


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Global Warming Potential (GWP)Global Warming Potential (GWP)

SubstanceSubstance GWPGWP TroposphericTropospheric

Abundance (%)Abundance (%)

COCO22 11 0.03750.0375

CHCH44 2323 0.00180.0018

NN22OO 296296 0.000310.00031

HH22OO 0.10.1 variablevariable

OO33 20002000 0.0000040.000004CClCCl33FF 2100021000 0.0000000280.000000028

CClCCl22FF22 2500025000 0.0000000260.000000026


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Increasing the GWP of aIncreasing the GWP of a

Greenhouse GasGreenhouse Gas When a different greenhouse gas absorbs inWhen a different greenhouse gas absorbs in

the window region of the IR spectrum; it willthe window region of the IR spectrum; it will

have a higher GW

Phave a higher GW

P *Biggest Effect*Biggest Effect

The higher the tropospheric abundance; higherThe higher the tropospheric abundance; higher

GWPGWP

The higher the lifetime of the molecule; higherThe higher the lifetime of the molecule; higher

GWPGWP


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Methane; CHMethane; CH44

Natural SourcesNatural Sources (~40%)(~40%)

Component of Natural GasComponent of Natural Gas

Decayed vegetable matterDecayed vegetable matterin wetlandsin wetlands

ManMan--made Sourcesmade Sources

Oil wellsOil wells

LandfillsLandfills

Rice paddiesRice paddies

Cattle and sheepCattle and sheep

Frozen methaneFrozen methanehydrate cageshydrate cages


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Methane Absorbs at the Edge ofMethane Absorbs at the Edge of

Window Region of IR SpectrumWindow Region of IR Spectrum


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Methane Absorbs at the Edge ofMethane Absorbs at the Edge of



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Nitrous Oxide, NNitrous Oxide, N22O; Laughing GasO; Laughing Gas

Manmade SourcesManmade Sources

Dental/medical UseDental/medical Use

FertilizersFertilizers

BurningBurningBiomass/catalyticBiomass/catalyticconvertersconverters

Production of nylon andProduction of nylon andnitric acidnitric acid

Absorbs in the WindowAbsorbs in the WindowRegion of IR SpectrumRegion of IR Spectrum


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Nitrous Oxide, NNitrous Oxide, N22O, Absorbs in theO, Absorbs in the

Window Region of the IR SpectrumWindow Region of the IR Spectrum


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Nitrous Oxide Absorbs in theNitrous Oxide Absorbs in the



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GasGas HumanHuman

Cont. toCont. toGlobalGlobal

WarmingWarming

18961896

Conc;Conc;ppbppb

19961996

Conc;Conc;ppbppb

2000Conc;2000Conc;

ppbppb

COCO22

55 %55 % 290,000290,000 360,000360,000 370,000370,000

CFCsCFCs 25 %25 % 00 33 77

CHCH44 15 %15 % 900900 17001700 18001800

NN22O, OO, O33 5 %5 % 285285 310310 315315


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Human Contribution of DifferentHuman Contribution of Different

Greenhouse Gases to Global WarmingGreenhouse Gases to Global Warming


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FeedbackFeedback

Positive; Amplifies/reinforces ongoing trendPositive; Amplifies/reinforces ongoing trend

Negative; Diminish/reverse trend to maintainNegative; Diminish/reverse trend to maintain

status quostatus quo


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Possible Impacts of Global WarmingPossible Impacts of Global Warming

Sea LevelsSea Levels

ForestsForests

BiodiversityBiodiversity

Food ProductionFood Production

WaterWater

WeatherWeather HealthHealth


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Climate Change and Sea LevelClimate Change and Sea Level


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Gl i N i l P kGl i N i l P k


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Glacier National ParkGlacier National ParkAll but 37 of 150 glaciers in the park haveAll but 37 of 150 glaciers in the park have

melted since 1850.melted since 1850.


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Glacier National Park1957 1998


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Global Climate Change

Melting

permafrost


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Coral BleachingCoral Bleaching

P ibl C f Gl b l W iP ibl C f Gl b l W i


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Possible Consequences of Global WarmingPossible Consequences of Global Warming

HighlyHighly

PlausiblePlausible

Global Av Surface WarmingGlobal Av Surface Warming

Global Avg. Precipitation IncreaseGlobal Avg. Precipitation IncreaseReduction in Sea IceReduction in Sea Ice

Surface Winter Warming at High AltitudesSurface Winter Warming at High Altitudes

PlausiblePlausible Global Sea Level RiseGlobal Sea Level Rise

More Summer MidMore Summer Mid--altitude Dryingaltitude Drying

High Latitude Precipitation IncreaseHigh Latitude Precipitation Increase

HighlyHighly

UncertainUncertain

Local Details of Climate ChangeLocal Details of Climate Change

Regional Distribution of PrecipitationRegional Distribution of PrecipitationRegional Vegetation ChangesRegional Vegetation Changes

Increase in Tropical Storm Intensity/FrequencyIncrease in Tropical Storm Intensity/Frequency


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Ways an Individual Can HelpWays an Individual Can Help

Reduce Global WarmingReduce Global Warming

Reduce use of fossil fuels; car pool, use massReduce use of fossil fuels; car pool, use mass

transit, walk, biketransit, walk, bike

Use energy efficient appliances and light bulbsUse energy efficient appliances and light bulbs

Plant trees (Cool house with shade trees)Plant trees (Cool house with shade trees)

Use solar energy to heat household as much asUse solar energy to heat household as much as

possiblepossible


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A major point of

disagreement of the

Kyoto Protocol isthat developing

countries do not have

to cut emissions as

much as developed

countries.

Greenhouse gas

emissions are

expected to increase

faster in developing

rather than

developed countries


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Global Warming vs. Ozone DepletionGlobal Warming vs. Ozone Depletion

Global WarmingGlobal Warming Ozone DepletionOzone Depletion

PossiblePossibleConsequences:Consequences:

Altered climate andAltered climate andagriculturalagriculturalproductivityproductivity

Increased sea levelIncreased sea level

Increased skinIncreased skincancer, damage tocancer, damage tophytoplanktonphytoplankton

PossiblePossibleResponses:Responses:

Use less fossil fuelUse less fossil fueland less deforestationand less deforestation

Eliminate use ofEliminate use ofCFCsCFCs


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Region of theRegion of theAtmosphere:Atmosphere:

Mostly troposhereMostly troposhere StratosphereStratosphere

MajorMajorSubstancesSubstancesInvolved:Involved:

COCO22, CH, CH44, N, N22OO OO33, O, O22, CFC, CFC

RadiationRadiationInvolved:Involved:

Infrared radiationInfrared radiationvibrates molecule &vibrates molecule &remit energy to Earthremit energy to Earth

UV Radiation breaksUV Radiation breaksapart Oapart O22 and Oand O33 & is& isfiltered in processfiltered in process


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Nature ofNature ofProblem:Problem:

More greenhouse gasesMore greenhouse gasesincrease avg globalincrease avg global

temptemp

Less ozone concLess ozone concincreases UV exposureincreases UV exposure

Source ofSource ofProblem:Problem:

COCO22 released fromreleased fromburning fossil fuels &burning fossil fuels &deforestationdeforestation

CHCH44 from agriculturefrom agriculture

CFCs (fromCFCs (fromrefrigerants, solvents,refrigerants, solvents,foaming agents)form Clfoaming agents)form Cl

free radical thatfree radical thatdestroys ozonedestroys ozone


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AIR QUALITY AND POLLUTION (TKA 3301) LECTURE NOTES 12- Global Air P Problem

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Transcript of AIR QUALITY AND POLLUTION (TKA 3301) LECTURE NOTES 12- Global Air P Problem