Why Does Acid Rain Erode Marble

During the past several years research in the effects of acidic deposition on carbonate stone has been conducted under the national acid precipitation assessment program napap 2 to define the incremental effect of acidic deposition under ambient environmental conditions.

Why does acid rain erode marble.

Acid rain is composed of sulfuric acid h2so4 or nitric acid hno3 formed as secondary pollutants from so2 other sulfur oxides and nitrogen monoxide no. Acid rains are one of the main degradation agents for marble artifacts. Acid precipitation affects stone primarily in two ways. Acids have a corrosive effect on limestone or marble buildings or sculptures.

Field investigations of acidic deposition effects on limestone and marble. In exposed areas of buildings and statues we see roughened surfaces removal of material and loss of carved details. Acid rain effects on buildings. It is well established that either wet or dry deposition of sulfur dioxide significantly increases the rate of corrosion on limestone sandstone and marble.

Igneous and metamorphic rocks exposed to acid rain can poison ecosystems. These constituents may occur naturally from processes such as volcanic eruptions and the oxidation of rocks or their presence in. Marble is mainly calcium carbonate. How does acid precipitation affect marble and limestone buildings.

Sulfur dioxide plus water makes sulfurous acid. Stone such as granite and gneiss release toxic aluminum ions into the environment when exposed to acid rain. But if you add an acid you add hydrogen ions h which will react with the carbonate to form hydrogen carbonate hco3 ions which are very soluble in water and the limestone will dissolve. Or if there is more acid two hydrogen ions will.

Limestone is mostly made up of the mineral calcium carbonate caco3. When sulfurous sulfuric and nitric acids in polluted air react with the calcite in marble and limestone the calcite dissolves. Stone surface material may be lost all over or only in spots that are more reactive. In the atmosphere rain mixes with carbon dioxide nitrous oxide and sulfuric dioxide to form acid rain.

This is not very soluble so rocks don t dissolve very quickly. When sulfurous sulfuric and nitric acids in polluted air and rain react with the calcite in marble and limestone the calcite dissolves. Marble like all calcareous rocks is particularly sensitive to degradation by acid chemicals and to weathering. Acidic precipitation can be caused by natural volcanoes and man made activities such as from cars and in the generation of electricity.

Acid rain is a byproduct of both natural and man made conditions. Erosion due to dissolution.