environmental chemistry ppt
TRANSCRIPT
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