Difference Between Acid Rain and Acid Precipitation

Acid Rain vs Acid Precipitation
 

The hydrological cycle is important in order to keep the balance of how water is cycled. The water, which is in oceans, lakes, and other reservoirs on the earth surface, are getting evaporated in the daytime. Trees and other organisms also give out a considerable amount of water. The evaporated water is in the atmosphere, and they aggregate and form clouds. Due to the air currents, the clouds can travel to farther locations than where they are made. The water vapor in the clouds can come back to the earth surface in the form of rain. Other than that evaporated water comes back to the ground in the form of snow, fog, etc.

Acids can be defined as substances that donate hydrogen ions. They have a pH lower than 7. When the pH of precipitation is below 5.6, it is considered as acidic. This pH value is far less than the pH of the distilled water. Mainly, natural precipitations have a lower pH value due to the reactions involved with atmospheric carbon dioxide.

Acid Rain

Rain is the main form in which the evaporated water from the earth surface is coming back to the earth. This is also known as liquid precipitation. Water is a universal solvent. When raining, the rain water tends to dissolve substances, which are dispersed in the atmosphere. Due to human activities today the earth atmosphere has been highly polluted. When there are sulfur dioxide gas and nitrogen oxide gases in the atmosphere, they are easily dissolved in rain water and come down as sulfuric acid and nitric acid. Then the pH of the rain water becomes less than 7, and we say that it is an acidic. Over the past few decades, the acidity of rain has increased significantly due to the human activities. SO₂ is produced in fossil-fuel burning and, in industrial processes, H₂S and S are produced. Nitrogen oxide is also produced from fossil fuel burning and power plants. Other than the human activities, there are natural processes in which these gases are produced. For example, SO₂ is produced from volcanoes and NO₂ is produced by soil bacteria, natural fires, etc. Acid rain is harmful to the soil organisms, plants, and aquatic organisms. Moreover, it stimulates corrosion of metal infrastructure and other stone statues.

Acid Precipitation

Acidic pollutants can be deposited onto earth surface from the atmosphere by several means. Rain is one form, which is discussed above. Other than that, pollutants can be incorporated in sleet, snow, fog, and cloud vapor. Then it is known as acid precipitation. That means, in various methods, acid precipitation takes place throughout the year. The acidity of these precipitations is really low in some places where air pollution is very high. This affects aquatic systems, soil organisms, plants, soil and the entire natural environment.