Air Pollution Control
Air pollution cannot be entirely abated but can control if specific measure takes. Control measures i.e. Control of gaseous/particulate pollutants from industry/automobiles using the equipment. So, in this note, you can find Air Pollution Control strategies and detail note on how we can prevent it.
Preventive Measures of Air Pollution Control
This measure mainly aimed at correction right at the source so there will be a lesser amount of pollutant emitted from the industry/automobiles.
Some of the important preventive measures are:
Selection of Suitable Fuel
- Using low sulfur coal in power plants
- With the use of natural gas in place of coal for power generation.
- Using LPG/CNG instead of diesel or petrol in automobiles.
Modifications in industrial processes and/or pieces of equipment to reduce the emissions
If coal is washed before pulverisation, then fly-ash emissions are considerably reduced.
Section of the suitable site and zoning for the industrial unit
Plan means setting aside separate areas for industries so that they are far from the residential areas.
So, this plan will help in the proper dispersion of air pollutants resulting in lower concentration of contaminants in the air of residential area.
Hence, by using proper environmental impact studies before setting the industry.
Control Measures for Air Pollution Control
When it is not possible to control air pollution at source some measure are to be adapted to control the level of contamination.
The most common method of eliminating or reducing pollutants to an acceptable level include.
Collecting the contaminants by using equipment to prevent its escape into the atmosphere.
Destroying the pollutants by thermal or catalytic combustion.
Changing the pollutants to a less toxic form.
By releasing the pollutants through tall chimneys for greater dispersion.
Control of Particulate Matter for Air Pollution Control
Particulate matter can control by using the following devices.
Gravitational Settling Chamber
The Gravitational Settling Chamber is used to remove particles with the size greater than 50 µm.
A velocity of the flue gas is reduced in the larger chamber thereby including settling of the particles under gravitational force.
Centrifugal force is utilized to separate the particulate matter from the gas.
As the centrifugal force in much greater than gravitational force, and smaller particles can be removed (10 to 50 µm).
Furthermore, the cyclones are widely used in industries producing larger quantities of gas containing large sized particles like cement and fertilizer plants, petroleum refineries, asphalt mixing plants, grain mills, cotton gins, etc.
Fabric Filters (Bag house filters)
In this device, fabric filter’s out the particulate matter from the gas stream and allow clear gas to flow.
And, it can remove particles up to 1 µm.
Control of Gaseous Pollutants
The gaseous pollutants can be controlled through the techniques of combustion, absorption and adsorption.
In the combustion process, oxidizable gaseous pollutants are completely burnt at a high temperature. This process is used to control gaseous pollutants in petrochemicals, fertilizer, paint and varnish industry.
In absorption technique, effluent gases are passed through absorbers containing liquid absorbents that remove, treat or modify one or more gaseous pollutant. So, the liquid absorbent may utilize either chemical or physical changes to remove pollutants.
So, in adsorption, the air pollutants are adsorbed on a solid surface.
Commonly used adsorbents are activated carbon, activated alumina, silica gel etc.
Control of Automobile Exhaust
The un-burnt hydrocarbon in auto emissions can be reduced by use of efficient engines.
The catalytic converter can convert NO to nitrogen gas and reduce potential hazards of NOx. It can also reduce CO and hydrocarbon emission.
First of all, Use lead-free petrol. The major factor affecting in air pollution control scenario.
By using cleaner fuel like CNG.
By proper maintenance of the vehicles.
And as result, developing good mass transportation facility.