Acid rain or acid deposition occurs when emissions of sulfur dioxide (SO2) and oxides of nitrogen (NOx)
react with water (vapor) in the atmosphere, oxygen, and oxidants to form various acidic compounds.
These compounds then are deposited on the land (and water) surfaces in either
- dry form (such as gas and particles) or
- wet form (such as rain, snow, and fog).
Wet scavaging describes the "wash-out" of pollutants (the various oxides) by precipitation;
this, however, makes the precipitation acirid, which then affects sois and vegatation, water bodies,
but also infrastrcuture (increased corrosion).
Environmental effects also depend on the buffer capacity of soils and water body, high in areas dominated by limestone.