NEET Chemistry Notes Environmental Chemistry – Environmental Pollution
Environmental Pollution
Environmental Pollution
Contamination of the environment (i.e. our surroundings such as air, water, soil etc.) with harmful wastes arising mainly from certain human activities is called environmental pollution.
Pollutants
Any substance which pollutes the environment is known as pollutant. A substance becomes a pollutant when it is present in larger concentrations which is harmful to the natural environment.
Types of Pollutants
- Primary Pollutants
These are the pollutants persisting in the environment ir the form, they are produced, e.g. carbon monoxide.
- Secondary Pollutants
These are formed by the combination of primary pollutants present in the environment, e.g. two primary pollutants, nitrogen oxides and hydrocarbons, react together in the presence of sunlight to form secondary pollutant, peroxyacetyl nitrate (PAN).
Types of Pollutants on the Basis of Biodegradation
- Biodegradable Pollutants
These pollutants are those which are decomposed by microorganisms either by itself or by suitable treatment, e.g. sewage, various oxides of nitrogen and sulphur, etc.
- Non-biodegradable Pollutants
These pollutants are not decomposed naturally and are not recycled. They are harmful to environment even in low concentrations, e.g. aluminium cans, 2+ salts, lead components, etc.
Types of Pollution
On the basis of pollutant, the pollution can be classified as:
- Thermal pollution
- Noise pollution
- Chemical pollution
- Metal pollution
- Smog pollution
- Oil pollution
On the basis of part of environment polluted, the pollution can be classified as:
- Air pollution
- Water pollution
- Soil pollution