AIR POLLUTION CONTROL ppt
AIR POLLUTION CONTROL ppt
Published on :-08/02/2022
AIR POLLUTANTS
- Carbon monoxide.
- Lead.
- Nitrogen dioxide.
- Ozone.
- Particles.
- Sulphur dioxide.
Sources of Air Pollution
- Mobile sources – such as cars, buses, planes, trucks, and trains
- Stationary sources – such as power plants, oil refineries, industrial facilities, and factories
- Area sources – such as agricultural areas, cities, and wood burning fireplaces
- Natural sources – such as wind-blown dust, wildfires, and volcanoes
Classification of air pollutants
The air pollutants can be classified in many ways as shown below:-
According to origin: The air pollutants are classified into:
Primary pollutants:
The pollutants that are emitted directly from identifiable sources produced by natural events
( eg: dust storms and volcanic eruptions) and human activities (eg: emissions from vehicles, industries etc.) are called primary pollutants. Eg: smoke, dust, oxides of sulphur & nitrogen, hydrocarbons and particulate matter etc.
Secondary pollutants:
The pollutants that are formed in the atmosphere by chemical interactions between primary pollutants and atmospheric constituents are known as secondary pollutants. Eg. Sulphur trioxide, ozone, ketones, sulphuric acid, nitric acid, carbonic acid etc.
According to state of matter: The pollutants are classified into:-
Gaseous air pollutants:
These pollutants exist in a gaseous state at normal temperature and pressure. They are carbon dioxide, nitrogen dioxide, sulphur oxides etc.
Particulate air pollutants:
These are not gaseous substances. They are suspended droplets, solid particles or mixtures of the two.
According to sources: Pollutants originate from:
Natural sources:
These include volcanic eruptions, deflation of sand and dust, forest or wild fires of natural vegetation, sulphur springs, natural geysers, organic and inorganic decays, vegetative decays, marsh gases, cosmic dust, pollen grains of flowers, photochemical reactions, soil debris etc.
Man-made sources:
These include human activities such as industries, factories, urban centres, aircraft, nuclear experiments, automobiles, agriculture, domestic burning of wood and burning of fossil fuels, deforestation, mining, waste treatment plants and power plants.
ch is injurious to health, of human, animal or plant life or which interferes with the comfortable enjoyment of life and prosperity” is known as air pollution.
EFFECTS ON HEALTH OF AIR POLLUTANTS
Long-term exposure to particulate pollution can result in significant health problems including: Increased respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing. Decreased lung function. Premature death in people with heart or lung disease, including death from lung cancer.
EFFECTS ON VEGETATION OF AIR POLLUTANTS
Weakened trees may also become injured more easily by cold weather. Whilst acid rain is a major cause of damage to vegetation, air pollutants which can also be harmful directly. These include sulphur dioxide and ozone. Sulphur dioxide, one of the main components of acid rain, has direct effects on vegetation.
EFFECTS ON MATERIALS OF AIR POLLUTANTS
The main pollutants affecting materials are sulphur dioxide and sulphates, nitrogen oxides and nitrates, chlorides, carbon dioxide and ozone. … Damage to materials in polluted atmospheres can be attributed to dry or wet deposition of pollutants, or dissolution in rainfall in the case of stone.
Effects on Materials:-
- The sulphuric acid will attack building materials containing carbonates. This will form CaSO4. The CaSO4 gets easily washed away leaving discoloured surface.
- Paper absorb SO2 causing the paper to become brittle.
- Leather looses the strength and flexibility.
EFFECTS ON ATMOSPHERE OF AIR POLLUTANTS
Each pollutants emitted to the atmosphere can affect directly or indirectly the human health. Along with harming human health, air pollution can cause a variety of environmental effects, such us acid rain, eutrophication, effects on wildlife, ozone depletion, crop and forest damages, global climate change.
REACTIONS OF POLLUTANTS IN THE ATMOSPHERE AND THEIR EFFECTS: SMOKE, SMOG AND OZONE LAYER DISTURBANCE
- SMOKE: Smoke primarily consists of particles and can include other gaseous air pollutants, including nitrogen oxides, carbon monoxide, and hydrocarbons that may be toxic.
- SMOG: Smog, is the chemical reaction of sunlight, nitrogen oxides and volatile organic compounds in the atmosphere, which leaves airborne particles and ground-level ozone. … The relevant secondary pollutants include peroxylacyl nitrates (PAN), tropospheric ozone, and aldehydes.
GREENHOUSE EFFECTS
Earth’s surface warms up in the sunlight. At night, Earth’s surface cools, releasing the heat back into the air. But some of the heat is trapped by the greenhouse gases in the atmosphere. … Greenhouse effect of Earth’s atmosphere keeps some of the Sun’s energy from escaping back into space at night.