The Sulfur Cycle

Aslan SmithJames Littrell

Olivia StephensKristina Pesce

WHAT is sulfur?Atomic number: 16. Symbol: S Native form: is a yellow crystalline (crystal like) solid. In nature: it can be found as the pure element, and as

sulfide and sulfate minerals.commercial uses: fertilizers, gunpowder, matches,

insecticides, fungicides, vitamins, proteins and hormones.

It is critical in the environment, climate and the health of ecosystems.

Random facts: it can also be referred to as brimstone.it’s the tenth most abundant element in the

universe

WHERE is sulfur found?

The majority of Earth's sulfur is stored:In rocks underground!In sulfur salts at the bottom of the ocean!

The Cycles:

Erosion, weathering, depositionPredominately atmospheric cycleMarine cycleSoil-plant cycle

The Cycles: part two!!

Mineralization of organic sulfur to the inorganic form hydrogen sulfide (H2S).    

Oxidation of sulfide and elemental sulfur (S) and related compounds to sulfate (SO4).

Reduction of sulfate to sulfide      Microbial immobilization of the sulfur

compounds and subsequent incorporation into the organic form of sulfur!

The Terrestrial Portion

Weathering of rocks release stored sulfur

Sulfur comes into contact with air and is converted into sulfate (SO4) ions

The sulfate is taken up by plants and microorganisms, converted into organic forms

Animals consume organic molecules containing sulfur, sulfur moves through the food chain

The death and decomposition of organisms release sulfur once again in sulfate form and some of it becomes part of the biomass of microorganisms.

The Atmospheric Portion

Volcanic eruptions, breakdown of organic matter in swamps and tidal flats, and the evaporation of water, especially seawater, release sulfur directly into the atmosphere

Sulfur eventually settles to earth or comes down with rainfall

In the Oceans

In oceans, sulfur moves through the various marine food webs

Some sulfur is lost in the ocean by being incorporated into ferrous sulfide and settling to the seafloor

Human ActivitiesThe burning of fossil fuels and processing of

metals releases huge quantities of sulfur into the atmosphere

Human activities are responsible for one-third of all sulfur emissions and 90% of all sulfur dioxide emissions

Sulfur dioxide emissions lead to acid rain as sulfur dioxide reacts with water to form H2SO4 and sulfur trioxide reacts with water to form H2SO4

READY FOR A POP QUIZ?

Flip to page three on your hand out. You will be given one minute to complete the following questions! Good luck!!

Answers!

Vitamins, proteins, fertilizers (others?)Volcanoes! (others?)The weathering of rocks! (deposition)Terrestrial/Atmospheric (Marine is also acceptable)Humans! 1/3rd in fact!

Sources:

http://www.enviroliteracy.org/article.php/1348.html

http://www.atmosphere.mpg.de/enid/Nr_6_Feb__2__6_acid_rain/C__The_sulphur_cycle_5i9.html

http://www.cliffsnotes.com/WileyCDA/CliffsReviewTopic/The-Sulfur-Cycle.topicArticleId-23791,articleId-23787.html