L15 Sulfur Cycle and Acid Rain Flashcards
Sulfur Cycle
Sulfur (S) is predominately found in inorganic form,
either in pure form, or in conjunction with a metal,
e.g., iron sulfide (FeS) or calcium sulfate (CaSO4
Sulfate Reduction
Sulfate may reprecipitate to form inorganic sulfur or
be reduced by bacterial activity to hydrogen sulfide (H2S)…..gas
Biochemical Reactions
Sulfur is also a constituent of several biochemicals required by organisms, including amino acids
What is Acid Rain?
- Sulfur from ancient organisms has became
incorporated into fossil fuels - With combustion, the sulfur in the fuels is oxidized to SO2, a gas which can be transported great distances in the atmosphere
- SO2 becomes H2SO4 when it dissolves in water
How is Sulfur Related to acid rain?
SO2 dissolves into rain and reacts to become sulfuric acid, a major constituent of acid rain:
2SO2 + 02 +2H2O –> 2H2SO4
H2SO4 travels through the hydrologic cycle and is eventually deposited on land and into surface
water
Acid rain impact: Lake Acidification
- Decreased pH and alkalinity (buffering ability) due to sulfate deposition
- Results in animal and plant death and decreased biodiversity
Acid rain impact: Forest Destruction
1) Direct:
- Killing trees and other plants
2) Indirect:
- Acidification of soil
- Stripping of soil nutrients
- Release of heavy metals
Acid rain impact: Infrastructure
1) Corrosion: Acid rain corrodes metals and materials like limestone, sandstone, and mortar.
2) Damage to paint: Acid rain can dissolve paint and damage protective coatings.
3) Structural damage: Acid rain can weaken the structure of buildings, leading to serious structural failures.