environmental chemistry ppt

AIR POLLUTION

Excessive discharge of undesirable foreign substances into the

atmospheric air thereby adversely affecting the quality of air and

causing damage to human, plants and animal lives.

Presentation submitted by: Gagan Arora

Project Guide: Dr. Tanuja Nautiyal

Air Pollutants

• Particulates – Dust, Smoke, Fly Ash

• Carbon monoxide (CO)• Carbon dioxide (CO2)

• Ammonia (NH3)

• Sulphur dioxide (SO2)

• Nitrogen Oxides (NxOy)

• Hydrogen Cyanide• Hydrogen Sulphide• Hydrogen fluoride• Chlorine

• Phosgene• Asbestos• Aldehydes• Radiations• Hydrocarbons

Classification of Air Pollutants

Primary Air Pollutants• The poisonous gases and

undesirable chemicals which cause air pollution.

• Carbon particles from unburned fuel, Ammonia (NH3), Sulphur dioxide (SO2), Hydrocarbons, Oxides of nitrogen, Oxides of carbon, Lead.

Secondary Air Pollutants• Derived from Primary Air

Pollutants• In bright sunlight nitrogen,

nitrogen oxides, oxygen and hydrocarbons – photochemical reaction – powerful oxidants – Ozone, Aldehydes, Sulphuric acid, Peroxy acetyl nitrate (PAN), Peroxides, etc.

• They form photochemical Smog

Sources of Air Pollution

Natural• Natural contaminants

(fungi, spores, cysts, bacteria, methane, dust, etc.)

• Carbon monoxide from Methane Gas

• Volcanic Eruptions• Forest fires• Electric storms and Solar

flares• Salt spray from oceans• Dust storms

Man Made• Rapid industrialization• Automobile Revolution• Deforestation

Classification of Pollutants

Gases• Oxides of Sulphur• Oxides of Nitrogen• Oxides of Carbon• Carbon dioxide• Ozone• Hydrogen Sulphide• Chlorofluoro Carbons• Hydrogen fluoride• Hydrocarbons• Photochemical oxidants• Aerosols

Particulates• Dust• Smoke• Fog• Smog

– London Smog– Los Angels Smog

• Fly Ash• Soot• Fumes• Natural Particulates

Effect of Air Pollution

• On Human Health– Irritate respiratory tract– Irritate eyes, nose and throat– Lead particles cause Lead Poisoning– Cadmium particles – Cardio vascular disease,

Kidney and Liver damage– Nickel particles – respiratory damage– Mercury – Central nervous system, kidney and

brain– Radioactive substances affect future generations

Effect of Air Pollution Contd...

• On Animals– Feeding particulate coated plants (fluorine,

lead, arsenic) – Arsenic Poisoning– Lead Poisoning – Bronchitis, Lack of appetite

in pet animals

Effect of Air Pollution Contd...

• On Plants– Spraying Pesticides, Organic manure and

agricultural applications – affect growth of plants – Destroy chlorophyll formation – disturb

photosynthesis– SO2 – decreases chlorophyll content – causes

Chlorosis– NO2 – permanent leaf fall– Ozone – Necrosis - dead area on leaf – damages

the leaves

Effect of Air Pollution Contd...

• On Materials– Corrosion– Abrasion– Deposition– Chemical attack on surface

Acid Rain

Effect of Air Pollution Contd...

• On Climate– Increase in CO2 – increase temperature of

atmosphere – ice and polar glaciers melt – flooding of coastal towns – change rainfall pattern – agricultural output changes

– Depletion of Ozone layer – increase penetration of harmful UV rays on earth – skin diseases, sunburns, inactivation of RNA, DNA and protein molecules

Control of Air Pollution

• Planting more trees• Reducing vehicle exhausts• Using less polluting fuels• Using mass transport• Removal of particulate matter using electrostatic

precipitator, cyclone filter, etc.• Industrial area should be cited far away from residential

area.• Suitable chemical methods applied to remove hydrocarbons• Multi stage combustion process – suggested to remove

oxides of nitrogen

Control of Air Pollution Contd...

• Activated carbon, charcoal, commercial zeolite and pulvarized lime stones can be used to remove polluting gases by absorption methods

• Use of tall chimneys reduces – concentration of air pollutants at ground level

Cyclone Collector

Cottrell Electrostatic Precipitator

SummaryDefinitionAir Pollutants

ClassificationPrimary Air PollutantsSecondary Air Pollutants

Sources of air pollutionNaturalMan made

Classification of PollutantsGasesParticulates

Effects of Air PollutionOn human healthOn AnimalsOn PlantsOn MaterialsOn Climate

Control of Air PollutionCyclone CollectorCottrell Electrostatic Precipitator