The Sulfur Cycle
Aslan Smith
James Littrell
Olivia Stephens
Kristina 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, deposition
Predominately atmospheric cycle
Marine cycle
Soil-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 Activities
The 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/CliffsReviewTo
pic/The-Sulfur-Cycle.topicArticleId-23791,articleId23787.html