Control of air pollution

The following are the approaches generally followed to control the emissions discharged into the atmosphere.

1. Proper planning and zoning of industrial and housing areas.
2. By using tall stacks (chimneys), the pollutants can be discharged at a sufficient height from the ground where air flow is more and thus help in the dispersion of the pollutants over a large area and dilute the concentration.
3. Reduction at source by process changing. This can be achieved            by 
i) Substitution of raw material. E.g. use of low volatile coal in place of high volatile coal to eliminate smoke and dust.
ii) Substitution of fuel. E.g. Compressed Natural Gas can be use in place of coal and oil to eliminate emission.
iii)    Modification of the process equipment or repair and maintenance of the existing equipment, help to reduce the emission.
iv)Reduction at source by using control devices like-
                     Gravitational settling
                     Cyclone separator
                     Fabric or bag filters
                     Electro static precipitator
                     Wet collector ( scrubber )