Question

What are the control technologies adopted for air pollution?

Answer 1

Air pollution control techniques have been divided into three phases:

(a) Pre-combustion techniques: These techniques involve the use of low-pollutant fuels and are mainly used in the reduction of sulphur, dust and ash content of coal. The use of natural gas and nuclear power is being promoted, which is helping reduce atmospheric emissions. Gasoline additives have been reduced and even banned in some countries.

(b) Combustion-modification techniques: These techniques are employed by developed countries to decrease sulphur dioxide and nitrogen dioxide emissions. These techniques are so expensive that developing countries cannot adopt them.

(c) Post-combustion control: It involves decreasing the pollution content of vehicle exhausts. Emission standards in many countries take measures to control sulphur dioxide emissions. People and agencies are now more inclined towards desulphurisation of fuel gases.