What is Acid Rain - Burning Issues

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Acid rain, also called acid precipitation or acid deposition, precipitation possessing a pH of about 5.2 or below primarily produced from the emission of sulfur dioxide (SO₂) and nitrogen oxides (NO_x; the combination of NO and NO₂) from human activities, mostly the combustion of fossil fuels.
When atmospheric pollutants like oxides of nitrogen and sulphur react with rainwater and come down with the rain, then this results in Acid Rain.
The causes of acid rain are Sulphur and Nitrogen particles which get mixed with the wet components of rain.
Sulphur and Nitrogen particles which get mixed with water are found in two ways either man-made i.e as the emissions are given out from industries or by natural causes like how a lightning strike in the atmosphere releases nitrogen ions and sulphur is released from volcanic eruptions.
The regular clean rain we experience, even though it is not clean i.e water and carbon dioxide react together to form weak carbonic acid which essentially by itself is not extremely harmful. The reaction occurring is :
H₂O (l) + CO₂ (g) ⇌ H₂CO₃ (aq)
Sulphur dioxide and nitrogen dioxide undergo oxidation, and then they react with water resulting in the formation of sulphuric acid and nitric acid respectively. The following reaction will clarify the acid formation reaction:
2SO₂(g) + O₂ (g) + 2H₂O (l) → 2H₂SO₄ (aq)
4NO₂ (g) + O₂ (g) + 2H₂O (l) → 4HNO₃ (aq)

Consequences of Acid Rain

Aquatic Ecosystem
Health
Plants and Trees
Stone Buildings and Monuments

Effects of Acid Rain

Effects on Acid Rain on Aquatic Animals
Acid rain can alter the pH value of surface water, which can cause severe damage to the aquatic life that lives in surface waters. Furthermore, acid rain can also contribute towards elevated aluminium concentration in the surface water
Effects of Acid Rain on Soil
The biological and chemical processes that occur inside soil can be seriously hampered by acid rains.
For example, the microbes that cannot tolerate acidic environments fail to adapt to the lowered pH of the soil and die

Soil Acidification

Soil acidification can be defined as the build up of hydrogen cations in soil, which is usually accompanied by a reduction in the soil pH. Acid rain is known to be a direct cause of soil acidification. The extent of the damage to plant life depends on the potency of the acid rain and the extent of soil acidification.
Ocean Acidification as a Consequence of Acid Rain
Although the impact of acid rain on oceanic ecosystems is not as severe, it can have several negative effects on oceanic life forms. For example, a drop in the pH of the ocean water (commonly known as ocean acidification) can make it difficult for certain species of coastal life to create their exoskeletons, which is essential for their survival. Therefore, ocean acidification can contribute to a loss of biodiversity.
Although acid rain is not directly harmful to human beings, the gases that cause acid rains are.
Sulfur dioxide and oxides of nitrogen, when present in large concentrations in the atmosphere, can cause respiratory problems in human beings. Furthermore, the fine particulate matter in the air can also contribute towards several medical conditions in humans such as bronchitis and asthma.
The only precaution that we can take against acid rain is having a check at the emission of oxides of nitrogen and sulphur.
We have so far seen the details of acid rain and its harmful effect on animals, plants and the monuments.
Being responsible citizens, one should be aware of the harmful effects they cause and of the industries which give out nitrogen and sulphur compound wastes unethically.

Prevention of Acid Rain

Liming:- The damage to water bodies can be prevented and eliminated by adding lime. Many chemicals such as caustic soda, sodium carbonate, slacked lime and limestone are most popular for increasing pH of acidified water. Liming completely removes only some of the symptoms of acidification and it is expensive and also not real cure.
Reducing Sulphur :- Reducing the amount of emission of So2 from power plants by burning less fossil fuels whereby also focussing on alternate energy sources like Tidal, Wind or Hydropower will do great wonders in reducing Acid Rain.
Policy Interventions
There have been many policy interventions for prevention of Acid Rain by global community as well as India.
In 1980s, Several north-eastern States of USA and the Ontario, Canada, sued the US Environment Protection Agency in 1980 to take action to control acid precursor emissions emanating from United States and subsequently U.S congress formed the National acid precipitation assessment programme (NAPAP) and mandated it to conduct a 10-year scientific, technological and economic study of the acid rain menace under the Acid Precipitation Act of 1980.
Acid rain is caused by:
carbon dioxide and nitrogen
carbon monoxide and carbon dioxide
ozone and carbon dioxide
nitrous oxide and sulphur dioxide

Q.)Below which of the following pH is rain regarded as ‘acid rain’?
a) 7
b) 7.3
c) 5.6
d) 6
Q.)Below which of the following pH is rain regarded as ‘acid rain’?
a) 7
b) 7.3
c) 5.6
d) 6
Q.)What does the term “liming” mean?
a) Application of magnesium and calcium rich substances to soil
b) Erosion of calcium carbonate(lime) zones in soil
c) Excessive growth of lemon trees in acid rain prone regions
d) None of the mentioned
Q.)What does the term “liming” mean?
a) Application of magnesium and calcium rich substances to soil
b) Erosion of calcium carbonate(lime) zones in soil
c) Excessive growth of lemon trees in acid rain prone regions
d) None of the mentioned
Q.) Who discovered the phenomenon of acid rain?
a) George Brown
b) James T. Stewart
c) Robert Angus Smith
d) Charles David
Q.)Who discovered the phenomenon of acid rain?