Saturday, February 2, 2008
Control of Air pollution by controlling Particulate Matters
Airborne particulate matters (PM) emissions can be minimized by pollution prevention and emission control measures. Prevention, which is frequently more cost-effective than control, should be emphasized. Special attention should be given to mitigate the effects, where toxics associated with particulate emissions may pose a significant environmental risk.
Measures such as improved process design, operation, maintenance, housekeeping, and other management practices can reduce emissions. By improving combustion efficiency in Diesel engines, generation of particulate matters can be significantly reduced. Proper fuel-firing practices and
combustion zone configuration, along with an adequate amount of excess air, can achieve lower PICs (products of incomplete combustion). Few following steps should be adhered to control PM:
1. Choosing cleaner fuels - Natural gas used as fuel emits negligible amounts of particulate matter.
2. Low-ash fossil fuels contain less noncombustible, ash-forming mineral matter and thus generate lower levels of particulate emissions.
3. Reduction of ash by coal cleaning reduces the generation of Particulate Matter (PM) emissions.
4. The use of more efficient technologies or process changes can reduce PIC emissions.
5. Advanced coal combustion technologies such as coal gasification and fluidized-bed combustion are examples of cleaner processes that may lower PICs by approximately 10%.
6. A variety of particulate removal technologies, are available – these are (a) Inertial or impingement separators, (b) Electrostatic precipitators (ESPs) , (c) Filters and dust collectors (baghouses), (d) Wet scrubbers that rely on a liquid spray to remove dust particles from a gas stream.
The principal methods for controlling the release of particulate matter are summarized here.
• Identify measures for improving operating and management practices.
• Consider alternative fuels such as gas instead of coal.
• Consider fuel-cleaning options such as coal washing, which can reduce ash content by up to 40%.
• Consider alternative production processes and technologies, such as fluidized bed combustion, that result in reduced PM emissions.
• Select optimal particulate removal devices such as ESPs and Baghouses.
Friday, February 1, 2008
Air pollution by Particulate matters (Fine and Coarse Dust particles):
Air pollution by Particulate matters (Fine and Coarse Dust particles):
‘Fine particles’ are less than 2.5 micron in size and require electron microscope for detection, however, they are much larger than the molecules of Ozone etc., and other gaseous pollutants, which are thousands times smaller and cannot be seen through even electron microscope.
Fine particles are formed by the condensation of molecules into solid or liquid droplets, whereas larger particles are mostly formed by mechanical breakdown of material or crushing of minerals. ‘Coarse particles’ are between 2.5 to 10 micron size, and cannot penetrate as readily as of Fine particle; however, it has been seen these are responsible for serious health hazards. The severity of the health hazards vary with the chemical nature of the particles.
The inhalation of particles has been linked with illness and deaths from heart and lung disease as a result of both short- and long-term exposures. People with heart and lung disease may experience chest pain, shortness of breath, fatigue etc., when exposed to particulate-matter pollutants. Inhalation of particulate matter can increase susceptibility to respiratory infections such as Asthma, Chronic Bronchitis. The general medical term given for such lung diseases is ‘Pneumoconiosis’.
Thursday, January 31, 2008
WE SEEK YOUR HELP TO SAVE ENVIRONMENT
Your few following small steps and effective decisions in everyday life would be a big leap in helping us to improve global environment.
- Make energy efficient and conservation wise decisions in every sphere of life.
- While driving motor vehicle, turn off the engine if waiting is longer. More fuel is wasted when idling than restarting. Be alert in traffic. Try to take alternate routes which have few signals to eliminate idling.
- Warm-up the motor vehicle for one minute before moving. Accelerate gently and evenly and use your cruise control to maintain a steady speed.
- Use motor vehicle's flow through vents instead of air conditioning (which decreases fuel efficiency by 21%) or by opening window.
- Keep car engine tuned. A poorly tuned car wastes 15% more fuel. More fuel, means more pollution and travel fewer miles.
- Properly inflate & align tires to save fuel & to reduce wear on tires over time.
- Reduce the amount of miles you drive. Fewer distance driven, fewer polluting emissions created. Walk or ride a bike!
- Use fuel efficient automobiles. Follow state guidelines on emissions testing & maintain any pollution-control devices.
- Use public transportation when available.
- Conserve electricity, including turning off lights when not in use.
- Participate in recycling programs. Recycling conserves energy and also conserves natural resources.