Acid Rain – Concept, Causes, Effects and How to Stop It

We explain what acid rain is and the causes of this environmental phenomenon. Also, its effects and how it would be possible to stop it.

Sour luvia
Acid rain are dilutions in water of carbonic, nitric, sulfuric or sulfurous acid.

What is acid rain?

Acid rain is known as a harmful environmental phenomenon, which occurs when, instead of water, various forms of organic acids precipitate from the atmosphere, the product of the chemical reaction between some types of gaseous oxides present in it and the condensed water vapor in the clouds. These organic oxides represent an important source of atmospheric pollution.

Acid rain is not usually strictly acidic, but diverse dilutions in water of carbonic acid, nitric acid, sulfuric acid or sulfurous acid, depending on the pollutants that abound in a region, since winds can move these gases over kilometers. This chemical reaction usually occurs in the following way, for example:

SO2 (gaseous sulfur dioxide) + OH (hydroxyl present in the atmosphere) = HOSO2, which in turn reacts with ambient oxygen: HOSO2 + O2 = H2O (water) + SO3 (sulfur trioxide), and the latter compound, highly polluting, reacts with water to produce H2SO4 (sulfuric acid).

The result of this mixture is usually around pH levels of 3 (similar to vinegar), which is much more acidic than the normal rainfall of 5.65 (due to the regular presence of atmospheric CO2 that gives rise to minimal amounts of carbonic acid).

In addition, this type of precipitation is usually affected by temperatures and climate, being able to take the form of dew, mist, hail, drizzle or even snow. Either way, their presence in the various ecosystems is usually pernicious, since they alter the chemical balance of the land, water and deteriorate life.

Causes of acid rain

Acid rain
The burning of fossil fuels can be the cause of acid rain.

As we have seen, the main direct cause of acid rain is the presence in the atmosphere of various polluting organic substances, such as sulfur and nitrogen oxides, which are usually frequent by-products of various human and industrial processes such as:

  • Combustion of fossil fuels. Typical of cars and vehicles that consume hydrocarbons such as coal, or petroleum derivatives.
  • Industrial boilers. Such as those present in power generation plants (especially coal), factories, metallurgical plants and other industrial plants.
  • Heaters. Many space heaters release this type of gas into the atmosphere during operation.

Effects of acid rain

Acid rain has various environmental effects, ranging from the gradual deterioration of plant life, whose leaves do not support the acidity of dew or rain, to the acidification of large bodies of water such as rivers or lakes, which often makes them uninhabitable by weaker life forms, causing chemical and trophic imbalances that can lead to extinctions or overpopulation.

Another known effect in this sense is the deterioration of the soils, since the acid molecules contribute protons to the soil (H +), forcing the production of certain ions (cations of iron, calcium, aluminum, zinc or lead) and impoverishing soil chemistry, making it less fertile and less suitable for cultivation.

In addition, acid rain is corrosive, so it deteriorates buildings and deteriorates materials, dissolving marble or limestone from statues, churches and period buildings.

How to stop acid rain?

Acid rain
Promoting public transport can be an alternative to prevent acid rains.

The measures to prevent the formation of acid rain always go through greater awareness of the polluting effects of the industrial world, and therefore effective control measures on the gases that we release into the atmosphere. Some common measures are:

  • Reduce the sulfur in fossil fuels and force drivers to use catalytic converters in their vehicles (public and private).
  • Migrate towards green technologies, or at least safer for the environment, especially in terms of obtaining electricity.
  • Add alkaline compounds to lakes and rivers to neutralize pH when acid rain is detected.
  • Ensure an industrial model that controls the emission of sulfur or nitrogen oxide gases, or in any case offer alternatives for the neutralization of these gases before they are discharged into the atmosphere.
  • Promote public transport and eco-healthy alternatives to the use of motor vehicles.