By: eman elkomy Br.khaled Acid precipitation By: eman elkomy Br.khaled

What is acid rain? Acid rain is rain or any other form of precipitation that is unusually acidic. It has harmful effects on plants, aquatic animals, and infrastructure. Acid rain is mostly caused by human emissions of sulfur and nitrogen compounds which react in the atmosphere to produce acids. Acid rain is a term referring to the deposition of wet (rain, snow, sleet, fog and cloud water, dew) and dry (acidifying particles and gases) acidic components. A more accurate term is “acid deposition”.

How acid rain is formed

What causes acid precipitation? Acid precipitation is mainly caused by air pollution through the burning of fossil fuels that produces elements such as sulfur and nitrogen. These elements react with the cloud molecules - water (H2O), forming acids which falls as rain (precipitation).

How does Acid rain effect plant growth? Plants grow in a specific range of pH. As you get to the edges of the pH range in which a specific plant grows, it grows more weakly and slowly. They produce smaller fruits and generally are not as healthy as plants growing in the middle of their pH range

Lake acidification begins with the deposition of the byproducts acid precipitation (SO4 and H ions) in terrestrial areas located adjacent to the water body. Hydrologic processes then move these chemicals through soil and bedrock where they can react with limestone and aluminum-containing silicate minerals. After these chemical reactions, the leachate continues to travel until it reaches the lake. The acidity of the leachate entering lake is controlled by the chemical composition of the effected lake's surrounding soil and bedrock. If the soil and bedrock is rich in limestone the acidity of the infiltrate can be reduced by the buffering action of calcium and magnesium compounds. Toxic aluminum (and some other toxic heavy metals) can leach into the lake if the soil and bedrock is rich in aluminum-rich silicate minerals.