THE ACID RAIN

INTRODUCTION: WHAT IS ACID RAIN?

Acid rain, also called acid deposition, refers to any sort of precipitation containing acidic components such as nitric or sulfuric acid and falls on the earth in damp or dry form from the sky. 

To answer the question “what is acid rain?” simple…

 It is a kind of rain that is typically acidic, indicating there are a lot of hydrogen ions in it, it has a low pH balance.

Most water forms including drinking water have a pH that is neutral, in between the ranges of 6.5 to 8.5, while acid rains have a pH that ranges much lower from 4 to 5 on an average. Acid rain is more acidic, the lower the pH. Flora, fauna, infrastructure and buildings can all be affected by acid rain.

Wet in the form of rain, snow, sleet, fog, cloud water, dew etc. and dry in the form of acidifying particles and gases acidic components combine to form acid rain. Distilled water has a pH of 7 after carbon dioxide is removed. Acidic liquids have a pH under 7, while alkaline liquids have a pH of more than 7. 

Because carbon dioxide and water in the atmosphere combine to generate carbonic acid, “clean” or unpolluted rain does have an acidic pH, but it is generally no less than 5.7.

Other compounds can also be found in unpolluted rain, affecting its pH (acidity level). Nitric acid, which is created by electrical discharges like lightning, caused in the atmosphere, is a very common example. In industrialised areas, pH readings of much under 2.4 have been found in rainwater and fog sometimes.

CAUSES OF ACID RAIN

The causes of acid rain are nitrogen oxides and sulphur dioxide released into the air. When nitrogen oxides (NOX) and sulphur dioxide (SO2) are emitted into the air and then transported by the wind and atmospheric currents, acid rain develops. Nitric and Sulfuric acids generate when NOX and SO2 fuse with water, oxygen, and other chemicals. After reacting with water and some other items, they fall down as acid rain on the earth.

Although some parts of NOX and SO2 producing acid rain happen due to natural factors like volcanoes, the majority originates from the ignition of fossil fuels.

The following are the primary sources of SO2 and NOX in the surrounding air: – 

• The combustion of fossil fuels to generate power is one of the biggest sources of SO2 and NOX in the atmosphere. Electrical power generators are accountable for 2/3rd of SO2 and 1/4th of NOX in the air.
• Automobiles and heavy machines, release pollutants into the air.
• Industries, oil mills, and a variety of different industries are just a few instances.
• Because wind may transport SO2 and NOX across enormous lengths including beyond borders, acid rain is a worry for all of us, not only people living nearby such origins.

Ever since the 1970s, several governments have taken several initiatives to reduce the degree of sulphur dioxide and nitrogen oxide emitted into the air. 

Because of extensive studies done on acid rain that began in the 1960s and widely spread information on its dangerous consequences, these initiatives have yielded positive outcomes. Acid rain is primarily triggered by industrial sulphur and nitrogen chemicals, but nitrogen oxides and sulphur dioxide are also produced naturally by lightning strikes and volcanic eruptions respectively.

TYPES OF ACID DEPOSITION

WET DEPOSITION

Wet deposition is the most common cause of acid rain. Nitric and  Sulfuric acids produced in the air fuse with snow, rain, fog or hail to fall down as acid rain to the ground.

DRY DEPOSITION

Acidic pollutants may descend as dry deposition from the air due to a lack of moisture. Acidic particulates and gases can easily settle down on places such as water bodies, vegetation, and structures or react to create bigger compounds in the air, presenting a health risk to humans.

As stored acids are washed off a surface by the time of the next precipitation, acidic water pours over and into the ground, destroying plants and fauna such as bugs and marine animals. The degree of acid in the air that drops to earth because of dry deposition is set on by the volume of downpour that happens in a certain region. Deserts, for example, have a greater proportion of dry to wet deposition compared to areas that experience a lot of rain every year.

ACID RAIN IN INDIA 

In some places of India, acid rain has already been documented.

Acid rain, often thought to be a Western affliction, is becoming a greater menace to India. Acidification of the environment has resulted from large-scale industrialization and dependency on coal and crude oil products like diesel. Vehicle exhaust gases are responsible as well, but thermal power plants running on coal combustion and the steel sector are the main offenders. A low pH has already been detected in Chembur, Maharashtra, and Delhi.

In India, acid rain is unlikely to happen anytime soon. This is because the country’s tropical climate and largely alkaline-rich soils neutralise pollutants, according to the Indian Meteorological Department’s Environmental Meteorology Unit (IMD). Gases that cause acid rain such as SO2 and NOX are neutralised by the alkaline composition of dust particles in India.

CONCLUSION

Acid rains are the result of harmful chemicals, particles and pollutants in the air.  SO2 and NOX are the main culprits for acid rains throughout the world. Several governments have taken many steps and initiatives to reduce the emission of these harmful substances in the atmosphere to lessen their impacts on the lives of human beings and all other creatures living on Earth.