Sulfur

Project Inspiration

This project was inspired by the following paper: Organosulfates in the Midwestern United States: Abundance, composition and stability

The Sulfur Cycle

The sulfur cycle describes how sulfur is transferred through water, rocks, and living systems. This cycle heavily relies upon the different oxidation states of sulfur.

Oxidative states of sulfur:

S2-: H2S, FeS, FeS2, CuS

S0: native, or elemental, sulfur

S2+: SO

S4+: SO2, sulfite (SO32-)

S6+: SO42- (H2SO4, CaSO4), SF6

The natural passageway of sulfur to the atmosphere is through sea spray. However, the primary anthropogenic cause of sulfur in the atmosphere is the burning of fossil fuels. When this sulfur is released into the atmosphere, it reacts with water to create sulfuric acid. This causes the pH of the water droplets in rain to become more acidic than usual and can damage natural systems.

Oxidation of Sulfur

Hydrothermal vents in the ocean floor emit hydrogen sulfide, which chemolithotropic bacteria use in conjunction with oxygen to create elemental sulfur or sulfate.

CO2 + 4H2S + O2 -> CH2O + 4S0 + 3H2O

CO2 + H2S + O2 + H2O -> CH2O + SO42- + 2H+

Sulfur Isotopes

Sulfur has 23 known isotopes, however, only four of them are stable. The stable isotopes of sulfur are: 32S (95.02%), 33S (0.75%), 34S (4.21%), and 36S (0.02%).

Air Sampling

Air Sampling

Relevant Papers

Effect of Acidity on Secondary Organic Aerosol Formation from Isoprene

Organosulfates in the Midwestern United States: Abundance, composition and stability