Know More About the Acid Rain Phenomenon

Basically, acid rain is defined as any kind of rain with a pH below 5.6. Rain is naturally acidic (pH slightly under 6) because carbon dioxide (CO2) in the air with a water-soluble form of the acid rain has weakened. Acids in the rain is very useful because it can dissolve the minerals in the soil needed by plants and animals.

Acid rain is one of the impact of the science and technology and the high activity of human economic activity. As a logical consequence, increasing pollutants also issued industrial activities and transport. The presence of pollutants in the air is certainly going to affect the physical processes occurring chemical in the air.

This phenomenon has actually been observed since the 17th century by Robert Boyle (1862) who called it a "Nitrous or Salinosul-phureous Spirit" in his General History of the Air, along with the industrial revolution in England. The process of acid rain can occur in urban areas due to air pollution from heavy traffic and the area directly affected by the polluted air from the factory. Can also occur in hilly areas exposed to the wind that brings air containing acid.

Graphic showing how acid rain is formed. (Picture from: http://commons.wikimedia.org/)

Dry deposition usually occurs at a place near the source of pollution, whereas wet deposition is falling in the form of rain. This occurs when the acid in the air dissolves into grains of water in the clouds. If later down rain from the cloud, the rain water will be acidic. In English, this event is called a rain-out. Wet deposition can also occur because of rain fell over the air-containing amino acids so that it leaches into the earth.

Acid deposition problem occurs in the lowest layer of the atmosphere, namely in the troposphere. The acid contained in acid deposition is sulfuric acid (H2SO4) and nitric acid (NHO3). Both are very strong acid. Sulfuric acid from SO2 gas and nitric acid, especially of NOX gases through physical and chemical processes in the air to form acid. The process that occurs is complex involving transport and transformation processes. Contribution of rainwater to bind pollutants form the acidity in the form of the compound H2SO4 and NHO3.

Acid rain and its effects to the environments and buildings. (Picture from: http://www.freewebs.com/)

Theoretically, in chemistry is explained that the degree of acidity is measured by pH indicates levels of H+ ions present in solution are expressed in -log levels of H+. Since the pH using a logarithmic scale, each scale mean multiple of 10. For example, a pH 3 is 10 times more acidic than a pH 4 and 100 times the acid of pH 5.

If the normal rains or not polluted rain has a pH of about 5.6. So, are slightly acidic. This is due to CO2 in the rain water. Acidic carbonic acid was contaminated by a strong acid, the pH of rain water falls below 5.6. The rain is called acid rain.

Acid rain is a phenomenon that a lot of air pollution associated with energy activities emit precursor main elements, namely SO2 and NOX. This activity is the most important anthropogenic activities, especially in the conversion and end use of energy. Cross-border transport of pollutants causing these problems became an international issue.

Naturally acid rain can occur due to eruption of the volcano and biological processes of soil and others. However, the majority of acid rain is caused by human activity, such as industry, power plants, motor vehicles and agricultural processing plant, especially ammonia. The gases produced by this process can be carried by the wind, before it turns into acid and deposited on the ground.

Acid rain has been scourging Europe’s 
forests and lakes for long. (Picture
from: http://www.greendiary.com/)

Acid rain caused by the industrialization process has become an important issue in China, Western Europe, Russia and the United States. Acid rain from power plants in the United States has destroyed the forests of New York and New England. This powerhouse generally use coal as fuel.

In this context, coal will be the main source of primary energy in Indonesia to meet the increasing needs in the decade and in the future. And government policies have also led to clear that coal is accompanied by the development of the power plant needs to be implemented in the future. Because, in addition to meeting increased energy needs, it also can save the use of petroleum that are becoming depleted reserves.

And these factors need to be cautious with the anticipation of acid rain in Indonesia, especially the big cities are pretty solid by the process of industrialization and motor vehicle activity. Efforts could do nothing else to reduce emissions of SO2 and NOX, such as by using a catalytic converter on every motor vehicle, alternative fuels using and doing energy savings. As for the process of industrialization (the factory) needs to be done more on Environmental Impact Assessment of the course will involve a lot of experts, not only from the environment but also social.

In general meteorological found that the factory should be built in areas with unstable atmospheric conditions. This will cause air pollution industrialization process will be carried away to leave the densely populated areas around the plant. *** [BUDI IMANSYAH | PIKIRAN RAKYAT 25102012]
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