air pollution presentation.ppt

04/15/2023Air pollution 1

AIR POLLUTIONID# Name Program

13103030 Mst. Jannatul Ara

BCSE


TABLE OF CONTENT What is air pollution? Major Air pollutants Source of pollutants Health effects How to reduce pollutants Conclusion


Air pollution:

Air pollution is the introduction of particulates, biological molecules or other harmful materials into the Earth's atmosphere causing disease, death to humans, damage to other living organisms such as food crops, or the natural or built environment. Air pollution may come from anthropogenic or natural sources.


AIR POLLUTANTSFor each air pollutant we need to know:

sources: natural and man-made methods of reducing its emissions any relevant balanced symbol equations


5 Major Pollutants:

1..) Carbon

Monoxide

2.) Sulfur Dioxide

3.) Nitrogen

Dioxide

4.) Particulate

Matter

5.) Ground Level

Ozone


Carbon Monoxide

•colorless, odorless

•produced when carbon does not burn in fossil fuels

•present in car exhaust


CARBON MONOXIDE: SOURCES Natural:

atmospheric oxidation of methane CH4 + ½ O2 = CO + 2H2

natural forest fires

Man-made: heavy traffic produces CO.


CARBON MONOXIDE: HEALTH EFFECT

CO combines with Fe in hemoglobin in blood – bonds 320 times stronger than oxygen – oxygen cannot bond onto hemoglobin.

Less oxygen supplied to body cells. Effects:

headaches, shortness of breath, in case of high concentration (e.g. rush hour):

unconsciousness, death.


Sulfur Dioxide

•produced when coal and fuel oil are burned

•present in power plant exhaust

10

SULPHUR OXIDES: SOURCES Natural:

volcanoes sea spraybiological decay of organic matter

that contains sulphur reduction of sulphates

Man-made: coal-burning power stations.roasting of metal sulphides e.g. ZnS

and Cu2S

04/15/2023Air pollution

http://en.wikipedia.org/wiki/Image:RatcliffePowerPlantBlackAndWhite.jpg

11

SULPHUR OXIDES: HEALTH EFFECTS acidic oxides lung irritants, affect in particular those

suffering from respiratory problems e.g. asthma sufferers

formation of sulphuric acid; effects of aerosols: irritant to the eyes irritate vessels in lungs causing impaired

breathing

04/15/2023Air pollution


Nitrogen Dioxide

•reddish, brown gas

•produced when nitric oxide combines with oxygen in the atmosphere

•present in car exhaust and power plants


NITROGEN OXIDES: SOURCES Natural:

Electrical storms release enough energy to cause oxidation of atmospheric nitrogen

Decomposition of organic matter containing nitrogen

Man-made: Combustion of fossil fuels in car engines and furnaces of power stations produces high temperatures to cause oxidation.


NITROGEN OXIDES: HEALTH EFFECTS choking irritating gas, affects eyes and people

with respiratory problems forms nitric acid aerosols/acid rain. nitric acid also increases the rate of oxidation of

SO2.

plays an important role in the formation of secondary pollutants e.g. ozone and smog


Particulate Matter

•particles of different sizes and structures that are released into the atmosphere

•present in many sources including fossil fuels, dust, smoke, fog, etc.

•can build up in respiratory system

•aggravates heart and lung disease; increases risk of respiratory infection


Ground Level Ozone

•at upper level, ozone shields Earth from sun’s harmful UV rays

•at ground level, ozone is harmful pollutants

•formed from car, power and chemical plant exhaust

•irritate respiratory system and asthma; reduces lung function by inflaming and damaging lining of lungs


PARTICULATES: SOURCESparticulates = airborne/suspended liquid and

solid particles. Natural:

volcanic eruptions large forest fires

Man-made: burning fossil fuels e.g. diesel forest fires industrial emissions; chemical processes incinerators


PARTICULATES: HEALTH EFFECTS

particulates penetrate lungs and may block air passages

some are poisonous e.g. Pb and asbestos adsorb chemicals and can act as catalysts in

reactions producing secondary pollutants by adsorbing also increase concentration and rate of reaction reduce visibility


•Combination of gases with water vapor and dust

• Combination of words smoke and fog

• Forms when heat and sunlight react gases (photochemical smog)

• Occurs often with heavy traffic, high temperatures


•1st smog related deaths were in London in 1873; death about 500 people; can we imagine how much worse the atmosphere is now?!

•Limits visibility

•Decreases UV radiation

•Yellow/black color over cities

•Causes respiratory problems and bronchial related deaths


AIR POLLUTION IN BANGLADESH Basically, there are two major sources of

air pollution in Bangladesh- industrial emissions: vehicular emissions


AIR POLLUTION IN INDUSTRIAL SECTORS

Air Pollution Percentage of most Five Industrial Sectors of Bangladesh in the Year 2010


Contribution of Vehicle Types to Emissions in Dhaka


AIR QUALITY IN DHAKA CITY The air quality standards are different

for residential, industrial, commercial, and sensitive areas. The worst affected areas in Dhaka city include: Hatchel, Manic Mia Avenue, Turgeon, Farm gate, Motijheel, Lalmatia, and Mohakhali.

Also many Report states that at peak hours Dhaka air at Motijheel Commercial Area has been found to contain 100 ppm of Carbon Monoxide,


MAJOR AIR POLLUTED AREAS

An statistics show that the major air polluted areas of Bangladesh are


CARBON MONOXIDE: REDUCTIONcatalytic converter in car exhaust system

reduction of nitrogen oxideoxidation of CO and unburnt hydrocarbons.

2CO (g) + O2 (g) 2CO2 (g) 2NO (g) + 2CO (g) 2CO2 (g) + N2 (g) 2C8H18 (g) + 25O2 (g) 16CO2 (g) + 18H2O (g)


SULPHUR OXIDES: METHODS OF REDUCTION

use of “low-sulphur content” fuels or removal of sulphur before burning coal/oil

removal of SO2 from fumes before they are released: limestone based fluidised bed alkaline scrubbing (wet scrubber)


NITROGEN OXIDES: REDUCTION

catalytic converter lean burn engines: high air/fuel ratio or low

fuel/air recirculation/reburn of exhaust gases: nitrogen

oxide emissions are reduced by reintroducing exhaust gases into the fuel mixture, lowering peak combustion temperatures as it is the high temperature in the combustion engine which causes nitrogen oxide production.


PARTICULATES: REDUCTION

Electrostatic precipitator

Particulates are given a negative charge and then attracted onto positively collection plates

.


•We can use bike

•We can tell our friends and family about pollution

•Make sure our parents get pollution checks on their cars

•Ride the school bus


•Learn more; stay up to date

•Join a group to stop pollution

•Encourage our parents to carpool to work

•Switch off lights, fan, heat, etc. when we leave the room


•Insel, Paul M. and Roth, Walton T. Core Concepts in Health: 9th edition. McGraw Hill: Boston, 2002.

•http://edugreen.teri.in/explore/air.html

•http://www.oneworld.net/penguin/pollution/pollution_home.html

•http://www.rcc.org/oem/aqindex.html

•http://www.tnrcc.state.tx.us/air/monops/lessoms/mathlesson.html

air pollution presentation.ppt

Government & Nonprofit