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Institute of Zoology, University of the Punjab, Lahore
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Zulfiqar
Submitted by: Arshia Naseer
Roll
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phil 08

Contents
Summary………………………………………………
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4
Sources and control of air pollutants…………………
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13
References……………………………………………
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Air pollution
can be due to the natural and anthropogenic sources
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Air pollutants are
airborne substances (solids, liquids, or gases) that occur in concentration high
enough to threaten the health of people and animals, to harm vegetation and
structures, or to toxify a given environment
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Auto, truck, or bus exhaust from attached garages, nearby roads, or parking areas,
paint (older homes, old toys, furniture, crafts), dust, soil, burning of fossil fuels
(coal and oil), volcanoes, forest fires, cigarette smoke, the incineration of
municipal waste and smokestacks or fires etc
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We can control air pollution either by source control or by Controlling
devices and technologies
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Controlling devices include Settling chambers, Inertial
separators or Cyclone, Electrostatic precipitator, Bag houses and filters and Wet
scrubbers etc
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Gaseous pollutants can be controlled by absorption and combustion process
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Sources of air pollution:
There are two major sources of air pollution
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Man-made sources:
• Deforestation
• Burning of fossil fuels
• Emissions from vehicles
• Smokes from industries
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For example:
• Carbon Monoxide
• Lead
• Nitrogen Oxides
• Ozone
• Sulfur Dioxide
• Benzene

• Cadmium
• Particulate matter
• Asbestos

Sources and control of air pollutants:
Some air pollutants, their sources and controls are as followings
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Unvented kerosene and gas space heaters
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Leaking chimneys and furnaces; back-drafting from furnaces, gas water
heaters and wood stoves
3
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4
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5
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g
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6
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➢ How to control CO?
• Have trained professionals inspect, clean and tune up central heating
systems, water heaters and any other gas, oil or coal burning appliances
annually
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Furnaces,
gas appliances, and fireplaces should all have ventilation systems
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• Do not burn charcoal,

kerosene lanterns or portable camp stoves inside a home, cabin, recreational
vehicle or camper
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Depending on the manufacturer,
an air purifier works to reduce or rid your air of microscopic particles,
volatile organic compounds (VOCs), and odorous gases
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Remove non-essential pieces from their reach
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Moisten or mist the loose
paint with water
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Collect the debris and seal it tightly in a plastic bag for disposal
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This flushes water
that may have become contaminated while standing in the pipes
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• When replacing household plumbing, select only lead-free materials
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►Nitrogen oxides:
➢ Sources of Nitrogen oxide:
• Nitrogen oxides are produced in combustion processes, partly from
nitrogen compounds in the fuel, but mostly by direct combination of
atmospheric oxygen and nitrogen in flames
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➢ Control of Nitrogen oxides:
• Combustion control may involve any of three strategies:
(a) reducing peak temperatures in the combustion zone
(b) reducing the gas residence time in the high-temperature
zone (c) reducing oxygen concentrations in the combustion
zone
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Process modifications include
using specially designed low-NOx burners, re-burning, combustion
staging, gas recirculation, reduced air preheat and firing rates,
water or steam injection, and low excess air (LEA) firing
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The
“ozone layer,” approximately 6 through 30 miles above the Earth’s
surface
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➢ Control:
• Surface ozone level must also be regularly monitored throughout
the country
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• Coal burning power plants can adopt clean coal technology to
reduce emissions
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It is produced from the burning of fossil fuels (coal and oil)
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➢ Control:
• The principal approach to controlling SOx emissions includes use of low
sulfur fuel
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• Use of appropriate combustion technologies and emissions control
technologies such as sorbent injection and flue gas desulfurization
(FGD)
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►Benzene:
➢ Source:
• Benzene is formed from both natural processes and human activities
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• Benzene is
also a natural part of crude oil, gasoline, and cigarette smoke
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• Stay away from cigarette smoke
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Cigarette smoke is a major source of benzene exposure
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Avoid skin contact with
gasoline
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• Use common sense around any chemicals that might contain benzene
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• If you are exposed at your workplace, talk to your employer about limiting your
exposure through process changes (such as replacing the benzene with another
solvent or enclosing the benzene source) or by using personal protective
equipment
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►Cadmium:

➢ Sources:
Cadmium (Cd) is a toxic heavy metal and is considered to be an
environmental pollutant
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➢ Control:
• Storage should be located indoor or covered to avoid wind-blow
emissions
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• Tipping to stockpiles can be made through chutes equipped with wet
suppression system or with dust suction to filter
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• Roads should be hard-surfaced and properly cleaned; contaminated
run-off water from roadways should be collected and a well-designed
wheel wash systems should be used
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• Most particles form in the atmosphere as a result of complex reactions of
chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants
emitted from power plants, industries and automobiles
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• PM
collectors often are added to the intake or exhaust of a ventilation system
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It is part of the source control
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• Internal air cleaners are located inside a building to clean the circulating and
mixing air
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►Asbestos:
➢ Source:
• Asbestos is still used in some construction materials
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• Asbestos fibers are released into the air when friable asbestos-containing
materials are disturbed
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Such deposits are often referred to as naturally occurring
asbestos
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The EPA
requires asbestos removal only in order to prevent significant public exposure and
generally recommends an in-place management program when asbestos has been
discovered and is in good condition
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Using trained and qualified contractors for control measures that may disturb
asbestos and for cleanup
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How to combat air pollution?
Air pollution can be controlled in two ways
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Control at source
2
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Control at source:
• Source relocation
• Source shut down
• Fuel or Energy substitution
• Process changes
• Good operating practices
• Vehicular emission control

2
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This complex mixture contains dust,
pollen, soot, smoke and liquid droplets
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1
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Inertial separators or Cyclone
3
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Bag houses and filters
5
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Settling chambers

• Settling chambers are the devices that are introduced to the industrial
exhaust system to remove solid particles from the emission
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The gas
stream enters the chamber where the velocity of the gas is reduced
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• Size, shape of particle and density are the important parameters
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Inertial separators or Cyclone
In this case when the gas enters in the system inertial forces are generated due to
which the particles start to move in circular pathway
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3
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•
Majority of particles get charged and collected on ground electrodes
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• Electrostatic precipitators is efficient from the particle size below 0
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4
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01
micrometer
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• The fabric filter is efficient at removing fine particles and can exceed
efficiencies of 99% in most applications
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Wet scrubbers
Objective of scrubbers is to entrain the particulate matter in liquid droplets water
subsequently flows from the bottom of the scrubber, the particulate is allowed to
settle and clarified water is re-circulated
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Sometimes direct
conversion of gaseous pollutants is possible by combustions
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• As the gas stream passes through the liquid, the liquid absorbs the gas
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Combustion

• This method for the removal of VOCs since they can be decomposed CO2
and H2O
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• The catalytic method is preferred when low temperature of the process is
desired
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References:
1
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epa
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Heinze, I
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, Stehle, P
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(1998)
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Environmental Health
Perspectives, 106(8), 499-501
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Prevention, P
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Nitrogen Oxides: Pollution Prevention and
Control
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Sujith, B
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(2017)
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International Journal of Medicine and Public
Health, 7(1)
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Jafarinejad, S
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Control and treatment of sulfur compounds specially
sulfur oxides (SOx) emissions from the petroleum industry: a review
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Int, 2(4), 242-253
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McIntosh, M
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(1992)
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Hazardous Waste Research and Information Center
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Li, Z
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, Wang, Y
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, & Wang, Y
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Spatiotemporal
variations in the association between particulate matter and airborne bacteria
based on the size-resolved respiratory tract deposition in concentrated layer
feeding operations
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8
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, Etaiw, S
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D
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, Bastawissi, H
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E
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, Radwan,
A
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, Dawood, M
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, & Panchal, H
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WCO biodiesel production
by heterogeneous catalyst and using cadmium (II)-based supramolecular
coordination polymer additives to improve diesel/biodiesel fueled engine
performance and emissions
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