Introduction
According to the mass balance of annual rainfall, over 70% of it is lost to direct evaporation and plant transpiration, with the remaining 30% flowing into streams. About 8% of this stream flow is used for irrigation, 2% for household purposes, 4% for industry, and 12% for electrical utilities. The two main uses of water are electric power plants and irrigation for agriculture. Increasing atmospheric sulphur and nitrogen oxides from human activities may be mostly to blame for the increasing acidity of rainfall that has been seen in many places of the world. Developing nations like India, where the rainwater is not yet acidic, should also be concerned about acid precipitation (Subramanian and Saxena, 1980).
The chemical makeup of atmospheric aerosols and particulate matter can also have an impact on the acidity of precipitation. Atmospheric NH3, which is primarily biogenic in origin, can partially neutralise the acids and reduce the acidity of rainwater. It has been believed that gaseous NH4 produced by bacterial activity in the farmed fields and alkaline dust produced by wind erosion can neutralise and so affect the amount of acid precipitation. The primary source of the observed high amounts of aerosols in the atmosphere is India’s soil, which is primarily dusty and rich in basic elements like Ca2+ and Mg2+ (Khemani et al., 1984).
According to Khemani et al. (1984), as long as the air’s aerosol condition, which is currently alkaline, remains that way, the phenomena of acid rain does not provide any unique challenges in India. However, in India, low pH levels in rainwater may only be seen in specific areas of heavily industrialised towns. Rainwater’s carbonic acid-bicarbonate buffer system is another element that is frequently overlooked. The concentration of these buffer components is crucial for keeping the pH of rainwater at or above 5.0 and for preserving a pH that is appropriate for living things.