air pollution conservation of natural resources.ppt

Air pollution

1. EFFECTS OF AIR

POLLUTION

Prepared by

2. Contents...

Effects of Air Pollution on human beings, plants
and animals and Properties. Global effects-
Green house effect, Ozone depletion, heat
island, dust storms, Automobile pollution
sources and control, Photochemical smog,
Future engines and fuels

3. On human being...

4. Introduction

Ÿ Air pollution : one of the greatest
“ENVIRONMENTAL EVIL”

Ÿ The air we breathe has not only LIFE SUPPORTING
properties but also LIFE DAMAGING properties.

V An average man breathes 22,000 times a day and takes
in 16 kg of air each day.

Y All thei impurtdes ft in the inhaled air do not necessarily

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5. Factors affecting human health

Y Nature of the pollutants

Y Concentration of the pollutants
Y Duration of exposute

Y State of health of the receptor
V Age group of the receptor

6. Target organ systems of air pollution

7. Respiratory Tract

Upper Respiratory Tract
Nasal Cavity

Pharynx

Larynx

Lower Respiratory
Trachea

Primary bronchi

8. Diseases caused by air pollutants

Health effects of pollution

Air pollution
Water pollution

co Parastes
Nerve Particulate matter Soll
damage Ozone contamination

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9. Effects of Air Pollution

Y Reduced lung functioning
Y Irritation of eyes, nose, mouth and throat
Y Asthma attacks

Y Respiratory symptoms such as coughing and
wheezing

Y Tactanced rentar diseases euch as heonehitea

10. Y Headaches and dizziness

Y Disruption of endocrine, reproductive and
immune systems

Y Neuro behavioural disorders
Y Cardiovascular problems
Y Cancer

11. Particulate Matter effect

Y Health effects
— Wheezing and coughing

— Heart attacks and death
y TSP (Total Suspended Particles)
— In presence of SO,, direct correlation between TSP

and hospital visits for bronchitis, asthma,
emphysema, pneumonia, and cardiac disease

— ~60,000 deaths from PM

12. Y PM,9 (<10 pm, coarse (2.5-10 um) and fine particles)

— Anything larger deposited in the HAR (nasal-
pharangycal)
Y PM, ; (<2.5 um, fine particles)
— Most serious health effects in alveolar/gas exchange
region
— shift in regulation focus
— May adsorb chemicals & intensify their effects

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13. Carbon Monoxide effect

Y Colorless, odorless, tasteless gas
> “Silent Killer”

Y Review...
— Cause: incomplete combustion

— Source: transportation sector, energy
production, residential heating units, some
industrial processes

14. Y Reacts with hemoglobin in blood
— Forms carboxyhemoglobin (HbCO) rather than

oxyhemoglobin (HbO,)
— Prevents oxygen transfer

Y Toxic effects on humans
— Low-level: cardiovascular and neurobehavioral

— High-level: headaches/nausea/fatigue to possible
death

y AB Sn A A PA APR

15. Y Concern in homes especially - Install CO
monitor!

— No indoor home regulations
* >70 ppm — flu-like symptoms (w/out fever)
+ 150-200 ppm — disorientation, drowsiness, vomiting
+ >300 ppm > unconsciousness, brain damage, death
— 500 Americans die/year from unintentional CO
poisoning

— Treatment: fresh air, oxygen therapy,
hyperbaric chamber

16. Ozone effect

Y Cause: product of photochemical reactions
Y Source: cars, power plants, combustion,
chemical industries
Y Acute Health effects
— Severe E/N/T (ear/nose/throat) irritation
— Eye irritation at 100 ppb
— Interferes with lung functions

17. No, effect

V Cause: Fuel combustion at high temps

Y Source: mobile and stationary combustion sources
Ÿ Prolonged exposure — pulmonary fibrosis,
emphysema, and higher LRI (lower respiratory tract
illness) in children
Y Toxic effects at 10-30 ppm
— Nose and eye irritation
— Lung tissue damage

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18. So, effect

Y Cause: Burning fuel that contains sulfur

V Source: Electric power generation, diesel trucks
V Gas and particulate phase

V Soluble and absorbed by respiratory system

Ÿ Short-term intermittent exposures
— Bronchoconstriction (temporary breathing difficulty)
— E/N/T irritation
— Mucus secretion

Y Lono-term exposures

19. Lead (Pb) effect

Y Source: burning fuels that contain lead (phased
out), metal processing, waste incinerators

Ÿ Absorbed into blood; similar to calcium

V Accumulates in blood, bones, muscles, fat
— Damages organs — kidneys, liver, brain, reproductive
system, bones (osteoporosis)
— Brain and nervous system — seizures, mental

retardation, behavioral disorders, memory problems,
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20. Mercury effect

Y Elemental Hg inhaled as a vapor, absorbed by lungs
Y Cause: vaporized mercury
Y Sources: coal combustion, accidental spill, mining
y Effects: Nervous system (acute, high), respiratory
system (chronic, low), kidneys, skin, eyes, immune
system; Mutagenic properties
Y Symptoms
— Acute: chills, nausea, chest pains/tightness,
couch oinoivitis oeneral malaise

21. Dioxins effects

Y Generic term for several chemicals that are

highly persistent in the environment
— chlorinated dibenzo-p-dioxins (CDDs)
— chlorinated dibenzofurans (CDFs)
— certain polychlorinated biphenyls (PCBs)
Y Cause: burning chlorine-based compounds with
hydrocarbons

22. ° Varying toxicity
— Generally problems with high exposures
— Exact effects of low exposures not really known

+ Health Effects
— Carcinogenic

+ Some are “known human carcinogen” (2,3,7,8
tetrachlordibenzo-p-dioxin, TCDD)

23. Bioaerosols effect

V Aerosols with organic origin
— Non-viable: pollen, dander, insect excreta, sea salt
— Viable: microorganisms
Y Cause: aerosolization of organic material
Y Sources:
— Human: sneezing, coughing
— Non-human: wind, waves, WWTP

24. Y Allergies
— Pollen, dander, fungi (spores)

Ÿ Airborne transmission of disease
— Bird flu, SARS, Legionnella (pneumonia)
— Indoor Air Quality

» Ventilation Systems — moist ductwork, protection,
recycled air
+ Office Buildings — Sick Building Syndrome
— Hospital (nosocomial)

+ Biological Warfare

25. On plants 200

26. Introduction

Y” Have an adverse effect on plants

V Cause a widespread damage to natural vegetation and
economic crops

Ÿ Many species are susceptible to damage even at low
concentrations

Y Gaseous pollutants are actively metabolized by some
plants and these plants are emploved as indicators of air

27. Pollutants affecting plants

Y SO,
YNO,
Y Ozone
Y PAN

Y Mercury

s/ TI a es & Ts MR

28. Forms of damages to leaves

+ Necrosis:
killing or collapse of tissue
« Chlorosis:

loss or reduction of chlorophyll resulting in fading
of the leaf’s green color to yellowish or pale green.

+ Abscission:

dropping of leaves

29. Kinds of injury to plants

- Acute injury
- Chronic injury
- Growth or Yield retardation
Acute injury:
short-time to high concentration occur under

fumigation conditions. Effects are noted within few hours
to few days- make visible markings on the leaves

Chronic injury:

30. So, effect

Acute injury

v The symptoms appear as 2-sided (bifacial) lesions that
usually occur between the veins and occasionally along the
margins of the leaves.

Y The color of the necrotic area can vary from a light tan or
neat white to an orange-red or brown depending on the
time, the plant species affected and weather conditions.

Chronic injury

31. Other effects are:

V Cell metabolism disruption (membrane damage, respiration
and photosynthetic effects)

V Leaf injury and loss
Y Reduced growth and reproduction

V Increase in susceptibility of plants to attacks by insect

33. No, effect

Y Seriously injure vegetation at certain
concentrations. Effects include:

Y Bleaching or killing plant tissue.
Y Causing leaves to fall.
Y Reducing growth rate.

34. PAN effect

v PAN has more soluble alkyl groups, will be readly
taken up by the plants.

Y PAN damage can occur at levels near 0.01ppm for a
few hours or even within a few minutes with a
levels near 0.1ppm

v PAN entry into the leaf through stomata. It affects
the parenchymatous in the vicinity of stomata.

35. V Enzymes, phosphoglucomutase and phosphorylase
are inhibited by PAN

Y It can inhibit the mobilization of starch in darkness
due to suppression of phosphorylase reaction.

Ÿ Also inhibits CO, fixation during photosynthesis

Ÿ Fatty acid synthesis is affected by PAN due to
oxidation of NADPH.

36. On animals...

37. Y Toxic pollutants in the air, or deposited on soils or
surface waters, can impact wildlife in a number of ways

Y Like humans, animals can experience health problems i
they are exposed to sufficient concentrations of air
toxics over time.

Ÿ Air toxics are contributing to birth defects,
reproductive failure, and disease in animals.

V Persistent toxic air pollutants (those that break down
slowly in the environment) are of particular concern in

38. Y Acid rain (formed in the air) destroys fish life in
lakes and streams.

Y Excessive ultraviolet radiation coming from the
sun through the ozone layer in the upper
atmosphere which is eroded by some ait
pollutants, may cause skin cancer in wildlife.

39. On Properties...

40. Introduction

Y Damage to property important economic aspect
of pollution.

v Damage to property covers corrosion of metals,
soiling, eroding of building surface, fading of
dyed material, rubber cracking.

41. AYN

Mechanisms deterioration

Air pollutants cause damage to materials by five
mechanisms:

. Abrasion

. Deposition and removal

Direct chemical attack

Indirect chemical attack

42. Factors influencing atmospheric
deterioration

1
2
3
4

. Moisture
. Temperature
. Sunlight

. Air movement

43. On building materials

Y Smoke and aerosols adhere to stone, brick and
building surface to produce unsightly coatings.

v SOx in presence of moisture react with
limestone and change the color. (Tajmahal)

Y CO2 in presence of moisture produce carbonic
acid, which causes leaching problem.

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46. On paints

V Areas high pollution require frequent painting.

Y Pollutants damage protective coating.

Y Common pollutants cause damage are O3, H2S,
SO2 and aerosol.

Y H2S cause darkening of surfaces covered with
paint containing white lead.

47. On textiles

Y SO2 causes deterioration of natural and
synthetic textile fibers.

V Permanent damage to nylon hose.

Y Fading of textile dyes by oxides of nitrogen,
ozone.

48. On rubber

V Cracking of rubber of side walls of tyres and
various forms of electrical insulation.

On leather

Y SO2 causes leather to lose much of its strength

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49. Green house effect...

50. gases in the atmosphere

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were” us

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51. The sun emits ultraviolet (UV)
radiation which hits the earth

52. These rays of light hit the earth
NY and reflect back towards space in

yx; T the form of UV as well as Infrared
2 > (IR) radiation ,,,,,,

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53. gases in the atmosphere pick up some of the heat from
the IR rays and disperse them back into the earth’s
atmosphere keeping the earth warm enough to sustain life

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54. On a molecular level...
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55. go
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When the electrons return to their ground state, they re-

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56. Only certain gases do this, just like dogs can heat
frequencies that humans cannot because their
eardrum vibrates with different wavelengths than
ours

57. If this didn't happen...

58. So greenhouse gases are called
greenhouse gases because they keep
some heat in the atmosphere to sustain
life on earth as a greenhouse does to
sustain life in the greenhouse when it is

cold outside

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59. Let’s find out which atmospheric gases
are green house gases

61. So why do greenhouse gases have such a

bad reputation?

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62. Selected Greenhouse Gases
Y” Carbon Dioxide (CO,)

Source: Fossil fuel burning, deforestation

x Anthropogenic increase: 30%
x Average atmospheric residence time: 500 years
Y Methane (CH,)

Source: Rice cultivation, cattle & sheep ranching, decay from
landfills, mining

x Anthropogenic increase: 145%

x Average atmospheric residence time: 7-10 years

63. Natural Versus Enhanced

Climate chemists believe that humans ate
producing more of the naturally occurring
greenhouse gases than the atmosphere can

64. Anthropogenic

65. Some greenhouse gases are not naturally
occurring — they are manmade

Hexafluoroethane

66. And Hydro fluorocarbons

Hole in the Ozone Layer?

Which once saved the earth!

67. CFC’s or Chlorofluorocarbons

68. UV light in the atmosphere would break
the bonds of the Chlorine in the CFC’s
and release it. Chlorine was found to
deplete the ozone.

69. Ozone depletion...

70. What is ozone?

Y” Ozone is made of three oxygen atoms

Y The oxygen we find in our atmosphere is made up of two
oxygen atoms

Y” Because of its chemical formulation, a single atom of oxygen (O)
is unstable.

Atomic

oxygen = Diatomic
& Pd

71. Position of ozone

Thermosphere

Mesosphere

72. Stratospheric and Troposphere
Ozone

Y In the troposphere, ground level ozone is a
major air pollutant and primary constituent of
photochemical smog.

Y In the stratosphere, the ozone layer is an
essential protector of life on earth as it absorbs
harmfaal TIV radiatian hefnra 14 reachec the earth

73. GROunD LEVEL OZONE
NO, + VOC + SUN LIGHT= Ozone

Industrial Mobile Area Biogenic
Sources Sources Sources Sources

74. How is Stratospheric ozone formed?

Y Ozone is formed naturally in the upper stratosphere by
short wavelength ultraviolet radiation.

Y Wavelengths less than ~240 nanometers are absorbed
by oxygen molecules (O,), which dissociate to give O
atoms.

Y The O atoms combine with other oxygen molecules to
make ozone:

75. How is Tropospheric ozone formed

Y N,+ O, >2 NO (heat)
V2NO +0,>2NO,

Y NO, > NO +0 (UV light)
YO+0, 30,

76. Ozone depleting substances

+ Chlorofluorocarbons (CFCs) — e.g. R11, R12
(phased out January 2006)

Y R11- refrigerant in chillers

Y R12 - refrigerant in refrigerators, car ait
conditioning units propellants in aerosol cans

° Carbon tetrachloride; methyl chloroform

77. * Halons (bromofluorocarbons or BFCs)
(phased out 2002 with exemption)

V Fire extinguishers

+ Methyl bromide (to be phased out in 2009)

Y” Pesticide (fumigant)

* Hydro chlorofluorocarbons eg. HCFCs
(freeze in 2013; phase out in 2030)

SF Rabat (abetted Lak EOS

78. SOURCES OF
OZONE DEPLETING SUBSTANCES

36.1%

12.0% SOLVENT CLEANING
PRODUCTS

ICTS

5.0% 3.0%

FOAM
PRODUCTS

REFRIGERATION
AND
AIR CONDITIONING

79. How CFC's interact with Ozone?

e

80. A | v Two ingredients are
Hole In the Ozone Layer! extremely important:
cold temperatures and
sunlight.

V Cold temperatures are
needed to form PSCs to
provide surfaces on
which heterogeneous
reactions take place.

Y Sunlight is required to

81. Effects of ozone de letion

Pig

Aquatic Ecosystems A
y ak La»

82. Effects of UV radiation on biological organisms

DNA damage... ... Maximum effect on small and single cell
organisms

Impaired growth and photosynthesis ...poor crop yields

Phytoplankton: . Reduced uptake of CO2

mortality

es Impaired reproductive capacity

Nitrogen-fixing soil bacteria .. Reduced, damaged

Human health effects:

Suppressed immune system................ Enhanced susceptibility to infection
..Increase risk of Cancer

Sunburn

..Loss of skin elasticity (Premature aging)
... Photosensitivity

-Melanocytic (malignant melanoma)

Dermatology (skin)...

Neoplasia (cancer)

83. The influence of the UV-B radiation on plant process.

UV-B

Molecular Targets

Photosynthesis

Gene Activity Metabolism

84. Effects on Human Health

° Over exposure may:

— Increase risk of non-
melanoma and malignant
melanoma skin cancer

+ Higher risks of
malignant melanoma
from severe sunburns —
especially in childhood

+ Risk of malignant

melanoma has increased
10%

85. Over Exposure

* Suppress immune system

* Accelerate aging of skin due high exposure

° Cause an outbreak of rash in fair skinned people
due to photo allergy — can be severe

ye

86. Alternatives of CFCs

+ First generation replacement of CFCs as
refrigerants : HCFCs

° Second generation replacement of CFCs as
refrigerants : HFCs

* Third generation replacement of CFCs as
refrigerants : ammonia vapor compression

87. Global Warming Can Increase Ozone
Depletion

Y continued global warming will accelerate ozone
destruction and increase stratospheric ozone depletion.

Y” Ozone depletion gets worse when the stratosphere
(where the ozone layer is), becomes colder.

Ÿ Because global warming traps heat in the troposphere,
less heat reaches the stratosphere which will make it
colder.

Y” Greenhouse gases act like a blanket for the troposphere
and make the stratosphere colder.

88. Urban Heat Island...

89. Jutnodluction

Y An urban heat island (UHI) is a metropolitan area which is
significantly warmer than its surrounding rural areas.

Y Dark materials absorb solar energy and release it back t the
surrounding air as heat. This condition causes the
temperature in urban areas to be much hotter than rural
arcas.

Y” The temperature difference usually is larger at night than
during the day, and is most apparent when winds are weak.

Y Seasonallv. UHI is seen durino both summer and winter.

90. Causes:

Y The main cause of the urban heat island is modification of the
land surface by urban development which uses materials which
effectively retain heat.

91. Reason for night time warming

Y The principal reason for the night-time warming is that
“buildings block surface heat from radiating into the
relatively cold night sky”.

Y Two other reasons:

Y thermal properties of surface materials.

92. Y Other causes of a UHI are due to geometric effects.

Ÿ The tall buildings within many urban areas provide
multiple surfaces for the reflection and absorption of
sunlight, increasing the efficiency with which urban
areas are heated.

V Another effect of buildings is the blocking of wind,
which also inhibits cooling by convection.

Y Waste heat from automobiles, air conditioning,
industry, and other sources also contributes to the UHI.

93. Social And Environmental Effects Of
Urban Heat Islands

v due largely to the thermal and topographical properties
of buildings that create effective heat traps for solar
radiation.

Ÿ they can cost cities millions in terms of health care and
energy usage.

Ÿ This results in a number of social and environmental
effects, such as

94. Y There are around 120 heat related deaths in London

every yeat.

Y” Inthe USA as a whole, 400 people die annually from
heat stress.

Y” In India:

Y” Orissa heat wave death- happened in 29' apr-20 death
rate-113

95. Reduced Precipitation in Urban Areas

V Because the cities are hotter than their surrounds, it will
receive less precipitation than their surrounds.

Y This can also have a knock on effect for

Y” water usage and the combination of high demand,

E A 1 1

96. Environmental effects of impervious
surfaces:

Y Impervious surfaces can modifies urban air and water

resources

Y The pavement materials seal the soil surface, eliminating
rainwater infiltration and natural groundwater recharge.

Y "Impervious surfaces collect solar heat in their dense
mass. When the heat is released, it raises air
temperatures, producing “urban heat islands“

97. Y The warm runoff from impervious surfaces reduces
dissolved oxygen in stream water

Y making aquatic life still harder.

Y Impervious pavements deprive tree roots of aeration,
eliminating the "urban forest“.

Y Because impervious surfaces displace living vegetation,
they reduce

98. Impacts on air and water:

Air:

Increased temperatures and sunny days help
lead to the formation of low-level ozone from
volatile organic compounds and nitrous oxides
which already exist in the air.

As urban heat islands lead to increased

99. Water:

Hot pavement and rooftop surfaces transfer
their excess heat to storm water, which then
drains into storm sewers and raises water
temperatures as it is released into streams, rivers,
ponds, and lakes.

Rapid temperature chances can be stressful to

100. The Effect of building materials on Albedo

Y Building materials generally have a lower albedo
than soil and vegetation.

Y” The result is that buildings, streets, parking lots, etc.
absorb more solar radiation than soil and
vegetation.

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102. The Effect of Building Materials on Storage of
Internal Energy

Ÿ Building materials generally have higher heat capacities
than soil and Vegetation.

Ÿ This means that buildings, streets and parking lots tend
to retain internal energy longer and stay warmer than
surrounding rural areas especially at night.

103. building materials have higher heat
capacities and store more internal
energy

Vegetation has lower heat
capacity and can’t store much
internal energy

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104. Generation of Internal Energy By Human
Activity

Y” Many human activities generate internal energy as a
waste byproduct (e.g. power plants, industrial processes,

energy loss from buildings).

Ÿ The much higher population densities in cities mean
that these processes generate much more energy than in

surrounding rural areas.

105. Internal energy generated asa result of
human activity very little internal energy

generated as a result of
human activity

PAN

106. Reduced Evaporation (Cont.)

Y The reduced evaporation in the city means that
the relative humidity is lower than it is in
surrounding rural areas.

Y Since water absorbs energy when it evaporates,
the reduced evaporation in the city also
contributes to hioher temperatures than in the

107. much less evaporation occurs over a muchmore water

evaporates in the

EE in

108. Relationship between land cover and thermal conditions

Thermal Infrared (IR) Profile

109. Heat Islands Contribute to
Global Warming

Y During the summer months they can
contribute to global warming.

Y The increased use of air conditioning and
refrigeration needed to cool indoor spaces in a
heat-island city, for example, results in the
release of more of the heat-trappino

110. Urban Heat Island Profile e

Temperature

SEIS BESE wa

111. Urban Heat Island Mitigation

action to reduce urban heat islands using four

main strategies:

1) increasing tree and vegetative cover,
2) installing green roofs (rooftop gardens or eco-roofs),

3) installino cool—mainlv reflective—roofs. and

112. Trees and Vegetation

Y Trees and other plants help cool the environment,
making vegetation a simple and effective way to reduce
urban heat islands.

113. Y Trees not only helps to reduce the urban heat island effect,
but also it reduces

Y air pollution.
Y higher demands on cooling systems and
Y health problems related to heat and pollution.

Y Trees are a very simple, attainable means of reducing the
effects.

Y They act as nature's air conditioners.

V Leaves help reduce air pollution by "capturing" airborne
nets we: pee AC

114. Green Roofs

Green roofs provide shade and remove heat from the air
through Evapotranspiration, reducing temperatures of the roof
surface and the surrounding air. On hot summer days, the
surface temperature of a green roof can be cooler than the air
temperature

115. Cool Roofs

Vv A high solar reflectance or albedo is the most important
characteristic of a cool roof as it helps to reflect sunligh
and heat away from a building, reducing roof
temperatures.

Y High thermal emittance help roofs to absorb less heat
and stay up to 50-60°F (28-33°C) cooler than

7

116. Benefits of Mitigation

Y” can reduce heating and cooling energy use.

Y” air pollution and greenhouse gas emissions, remove air
pollutants.

V lower the risk of heat-related illnesses and deaths.
Y” improve storm water control and water quality

Y increase property values.
Pi 1 Ce. .& .11 .

117. (lutomobile pollution
sources and centiol...

118. What is Combustion? ?

Y Combustion occurs when a fuel reacts
with oxygen to give off heat and light.

*

Air provides enough oxygen (~20% oxygen, ~80%
El nitrogen)

Y Fuels are typically made of carbon and
hvdrooen (hvdrocarbons) "AA

119. Why Do We Care?

V Burning of fuel is the energy source for almost all types ¢
automobiles

Y” Combustion accounts for 85% of all worldwide electricit
production

120. BUT,

Y Combustion accounts for 90% of all airborne
pollution

Y Air pollution can lead to lung problems and
shorter life spans

121. Combustion

Y Ideal combustion produces only carbon dioxide,
water, and ENERGY:
— Natural Gas:
CH, +20, > CO, + HO

— Gasoline (approximate):
C,H,, + 12 0, — 8 CO, + 8 HO

122. Real Combustion

V Fuel does not exist as a pure substance

—varying hydrocarbon chains
* Jet and diesel fuel contain hydrocarbon chains of 12
to 20 carbons in length. Fuel oil contains
hydrocarbons 20 to 40 carbons long.

—sulfur (S)

—nitrogen (N)

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123. Emissions: Automobiles

* Let's look at what happens in ideal and real combustion
in automobiles. The symbols we will use are shown
below:

* Hydrogen (H) + Nitrogen (N)

124. Oxygen

Ideal vs. Real Combustion

Nitrogen =>

Carbon
dioxide

>

Water Nitrogen

o od

Carbon
dioxide

Nitrogen

Water

125. Primary Emissions from Automobiles

Y Carbon monoxide (CO)

Y” Oxides of nitrogen (NO, NO,)
V Carbon as soot or particulates

Y Unburned fuel (hydrocarbons)
Y” Carbon dioxide (CO,)

Y Water (H,O)

126. Carbon Monoxide

Y Carbon monoxide (CO) — a non-irritating (won't

make you cough), Colorless, tasteless, and odorless gas.

Y Source: rich combustion - too little air or too
much gasoline

127. Carbon Monoxide

Y CO is POISIONOUS because it reduces the ability of
blood to bring oxygen to the body’s cells and tissues.

Y Remember that oxygen is needed for the
combustion that gives our bodies energy.

128. Nitrogen Oxide

v Nitrogen oxide (NO,: mainly NO, NO»)

Y” Source: lean combustion - too little gasoline or too much
ait

129. Nitrogen Oxide

— Environmental Effects:

+ NO, is an component of acid rain
—can damage trees and lakes
+ NO, reacts with other chemicals in sunlight to
produce ozone > smog (brownish haze)
— Health Effects:
* Lung damage

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130. NO,, Emissions

NOx Emissions
(Contributions by Source)

B Transportation

B Fuel Combustion

O Industrial
Processes

131. Particulate Matter (PM)

Ÿ Particulate Matter (PM) - small solids and liquids
suspended in the air.

V ex: Dust, Smoke, Soot

132. Particulate Matter

— Health effects:

Y Nose and throat irritation
Y lung damage, bronchitis
Y early death

— Environmental effects:

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133. Secondary Pollutants

Y When emissions react with other chemicals in the
atmosphere, they make secondary pollutants.

134. Greenhouse Gases

Green house gases

—Gases that trap heat like a blanket surrounding the
Earth.

A normal concentration of these gases keep our planet at

steady temperature, but the temperature can rise if we hav

too many in the atmosphere.

Greenhouse gases:

135. Some of the sun’s Some of the sun’s radiation is
radiation passes through reflected back into space by the
the atmosphere and hits atmosphere and Earth.

the Earth to warm it up.

SPACE

After bouncing off the
Earth, the radiation has
lower energy that is
absorbed by greenhouse
ses.

VW
<= >
LA

136. Secondary Pollutants

But wait! There’s more!

> NOx reacts with other chemicals in sunlight to
produce ozone + Ozone is called smog (brownish
haze) in the lower atmosphere

> Smog and PM reduce visibility and lead to health

137. Ozone

Y” Ozone is a colorless odorless gas
made of oxygen.

Y Ozone is O, - three oxygen atoms
joined together.

Ÿ Ozone is helpful in the upper
atmosphere by shielding us from

1. #4

138. Conclusion

Y It is impossible to eliminate harmful emissions,
but... it is the responsibility of every one of us to
reduce energy consumption!!

139. Emission Control

Exhaust Emissions are produced by cars, buses, and
motorcycles.

Four basic types of exhaust emissions:

1. Hydrocarbons (HC)

2. Carbon monoxides (CO)
3. Oxides of nitrogen (NOx)
4. Particulates.

140. Emission Control

Hydrocarbons (HC)

Y Resulting from the release of unburned fuel into the
atmosphere.

Y Produced by incomplete combustion or by fuel
evaporation.

Y Mostly related to ignition problems.

Y Effect could be eye, throat, and lung irritation, and,

141. Carbon Monoxide (CO)

Y Extremely toxic emission resulting from the release of
partially burned fuel (incomplete combustion of
petroleum-based fuel).

¥CO prevents human blood cells from carrying oxygen

to body tissue.

Y Symptoms are headaches, nausea, blurred vision, and
fatigue.

142. Oxides of Nitrogen (NOx)

Y Produced by extremely high temperatures during
combustion.

Y Air consist of about 79% nitrogen and 21% oxygen.
Y With enough heat (above 2500°F / 1370°C), nitrogen
and oxygen in air-fuel mixture combines to form NOx

emissions.

Y An engine with high compression ratio, lean air-fuel

143. SOURCES OF VEHICLE EMISSONS
‘Engine Crankcase Blow-by Fumes (20%)-

and burning of fuel that blows past piston ring
the crankcase.

*Fuel Vapour (20%) — chemica
enter the air as fuel evaporate.

Before
FAST.

144. Engine Modification Related to
Emission Control
Lower Compression Ratios

*Use of unleaded gasoline that permits use of catalytic converters and burns
completely to lower HC emissions.
*Lower combustion temperature = Lower NOx emissions.

Smaller Combustion Chamber Surface Volume
*Reduce HC emissions.
*Lowers the amount of heat dissipation out of the fuel mixture.
*Reduce the chance of fuel condensation.

145. Catalytic Converter

Y Oxidizes (burns) the remaining HC and CO emissions that
pass into the exhaust system.

Y Extreme heat (1400°F/760°C) ignites these emissions and
change them into carbon dioxide (CO) and water (H,O).

Ÿ Catalyst is a substance that speeds a chemical reaction without
itself being changed (coated with ceramic honey comb).

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146. Photochemical smog...

147. Photochemical smog ??

Noxious mixture of highly reactive and oxidizing
ait pollutants including:

° Oxides of Nitrogen (NO,)

+ Volatile organic compounds

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148. Generation Mechanism:

Three ingredients required:

° Ultraviolet Light
* Hydrocarbons

+ Nitrogen oxides

149. Generation Mechanism contd..

Nitrogen dioxide: NO2

Photochemical smog
jant

Oxidants consisting mainly

ofozone (03)

150. Photochemical Reactions

Troposphere Ozone:
* NO, +hv— NO+O
* O+0, —O,

Sources:

+ Exhaust gases From Motor
vehicles

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151. Photochemical Reaction Contd..

Volatile Organic Compounds (VOC)
Carbon-based molecules such as Aldehydes,

Ketones and Hydrocarbons
RCH, + 20, + 2NO ——RCHO + 2NO, + H,O

Soutces:

+ Paint thinners, solvents and petroleum constituents

152. Photochemical Reaction Contd..

Peroxyacetyl Nitrates (PAN)

Are secondary pollutants formed from
peroxyacid radicals and NO,

— CH¿CHO + OH’ — CH,¿C'O + H,O
— CH;C'O + O, 7” CH,C(O)OO*’ (acetylperoxy)

153. Effects on human health

Y Ozone

— Cause acute respiratory problems

— Aggravate asthma

— Cause temporary decreases in lung function in healthy adults
— Lead to hospital admissions and emergency room visits

— Impair the body's immune system

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154. Effects on human health contd..

Y Volatile organic compounds (VOCs)
— Global warming- Methane
— Carcinogenic- benzene

— Form Ozone

155. Future engines and; fuels. ..

156. ternative Energy Cars

n alternative fuel vehicle is a vehicle that runs on a fuel
other than "traditional" petroleum fuels, and also refers to
any technology of powering an engine that does not involve
running solely on petroleum. Also, it has increasingly begat
to refer to vehicles that are very fuel efficient.

Looking at 3 specific types of energy efficient cars:
- Battery Electric
- Hydrogen Cell

157. ros an ons

- Overall, Environmentally - Complex system- more
responsible likely to break down
m Fewer to no emissions - Higher initial price of car,

depending on vehicle type
- Higher cost to fix compare
- Less use of non- to that of regular cars

renewable resources
- Possible inconvience

158. Battery Electric Cars

Y Electric motor and
motor controllers
Y Low running costs

compared to

gasoline cars
y High energy

efficiency

159. Battery Electric Cars

Y Reduced carbon dioxide
emissions

Y No pollution at the
tailpipe

Y Charging time depends
on the type of battery
and power grid

160. Hydrogen Cell Cars

Ÿ Alternative fuel car that uses hydrogen as its onboarc
fuel.

Y Reacts hydrogen with oxygen in a fuel cell to run
electric motors

Y Sequel—a fuel cell-powered vehicle from General
Motors 9

161. Hydrogen cell cars

Y Hydrogen fuel is not naturally occurring, but can be
produced from multiple sources

o Wind, solar and nuclear

V Issue lies with the current fact that the energy content
per unit volume is too low to be efficient

162. Hybrid Electric Vehicles

Y Most common form is the hybrid electric car

y Combines conventional internal combustion engine
(ICE) propulsion system with electric compulsion
system

V Can be fueled with

gasoline, diesel,
Bus Pe O Mage eee ST

163. Hybrid Electric Vehicles

Y Technology
" regenerative braking
" electric motor drive/assit
“automatic start/shutoff

Y Different degrees of hybridization

Y Environmental Impact

164. Future Green Cars

Y Solar Power
o Solar panels harvest solar energy from sunlight
o Photovoltaic Cells (PV's) in panels convert sunlight t«
electricity
Y Biodiesel
o Fuel comprised of natural ingredients (corn, soybeans
animal fat, etc.)
o Usually mixed with normal diesel fuel
Y Super capacitors

165. Future Car Obstacles

Y Solar
o Way in which cars are stored
o High PV cost and lifetime
Y Biodiesel
o Increase in NOx emissions resulting in increase in
smog
o Decrease in power
o Amount and availability of biodiesel
Y Super capacitors