Acid Rain: Causes, Effects and Control
During normal rain pollutants are cleane . If rain fall continues rainwater clean the air from pollutants. Sulphat , ammonium and nitrate can be reduced by normal rain up to 30 to 73%. While the gases i.e. sulphur dioxide, Ammonia, Chlorine and NO2 can be decreased by 24 to 63%. The amount of NO2 in 72% areas of Lahore city is higher than standard values set by Pakistan and US EPA. These results are the indication of bad air quality in city.
To control acid rain there is a need to reduce amount of sulphur dioxide and oxides of nitrogen released into the atmosphere by using less energy and clean fuels (natural gas), by using catalytic converters and by flue gas desulphurization. Also acid rain can be reduced by fuel switching or scrubbing. Fuel switching is to limit the use of sources containing sulphur. Coal are switched to coal which emit less sulphur and in place of oil use gas or any other energy source such as gas boilers instead of oil boilers. Scrubbing is the use of electrostatic precipitators in which positively charged sulphur particles are attracted by negatively charged particles. To reduce NOx methods such as Selective Catalytic Reduction Process (SCR) are used. This method reduce NOx up To 80% . In automobiles NOx can be reduced by using Catalytic Converters. These catalyst reduce NOx by 3 ways of conversion of NOx:
- Conversion of NOx into N2 and O2;
- Conversion of CO into CO2;
- Conversion of hydrocarbons into CO2 and H2O.
Buffering Capacity
Many forests ,streams and lakes are not effected by acid rain because of soil of that area. In those areas soil an buffers the acid rain by neutralizing acidity of rain water in it. This capacity of soil depends on soil composition and thickness and also on bedrock under soil. In areas like mountainous parts of North East United States, the soil thickness is less and lack ability to neutralize the acid rain water. Hence these areas are vulnerable to harmful effects of acid rain.
Episodic Acidification
Melting of snow and heavy rain can result in episodic acidification. Lakes that do not normally have a increased level of acidity may experience some effects of acid rain for a short period of time. In this short period of time acidity of lake remain high and soil can’t buffet it. This short duration of higher acidity (lower pH) can result in a stress of ecosystem for short time. In this short time some species of plants and animals may be injured or even die.
Conclusion
Acid rain has many disaster effects in all over the world. Acid rain damage buildings and decrease their beauty of attraction acid rain also effects plants and trees and forests directly or indirectly. Acid rain damage chlorophyll in plants due to which their photosynthesis process in effected and plant die. Acid rain in human cause asthma, cough, eyes infection, nose irritation etc. Due to Acid rain pH of water bodies increased above average level and result in death of fish and other aquatic animals and plants. Acid rain can be controlled by different programs and awareness among people about it causes. We can control acid rain by using clean fuel in automobiles and industries built outside of cities and their waste should be disposed for prevention from its effects.
