The pollutants from industries are of different types and carry varying importance. The type of pollutant generated out of manufacturing process depends upon the nature of materials used during manufacturing process as wall as technology adopted to process them.
Highly dangerous gas with a high potentiality of causing cancer and respiratory ailments. Generally, it is evolved, when a fuel is burnt under limited supply of oxygen.
It is also a pollutant, when generated in large quantity - because it can reduce the oxygen concentration in the air. It is a gas produced when fuel is burnt in adequate oxygen.
Normally, the atmospheric air will have 0.03% CO2. When its concentration increases due to pollution, it reduces the percentage of oxygen in atmosphere.
Sulphur dioxide(SO2) is one of the dangerous pollutant with a potentiality to form sulphuric acid, when mixed with water vapour. Water vapour commonly available in air can mix with SO2 gas and produce sulphuric acid.
Such sulphuric acid is the cause of acid rain.
Dry and Wet Acid Deposition or Acid Rain
Hydrogen Sulphide(H2S) is one of the dangerous, pungent pollutant gas with many deleterious effects respiratory tract. It is released from many industries as a part of sulphonation process.
Hydrogen Cyanide (HCN)
When cyanide chemicals are used in manufacturing process, hydrogen cyanide is formed as a by product. It is a highly corrosive and poisonous gas leading to eye irritations, respiratory problems as well as other complications. In high doses, it can cause death.
In many industries, ammonia gas (NH3) is used as reducing agent. It is a corrosive gas with a high potentiality of causing throat irritations, burning of pharynx, oesophagus, etc. It can also cause digestive problems - when excess gas is inhaled.
The types of liquid pollutants can be
- acids - hydrochloric, acetic, fumaric, sulphuric, nitric, benzoic
- bases - hydroxides of sodium, calcium, magnesium
- carboxylic compounds
- nitrogenous wastes