(TTH 8:30 – 10:00)
The sulfur cycle is the collection of processes by which sulfur
moves to and from minerals (including the waterways) and
living systems. Such biogeochemical cycles are important in
geology because they affect many minerals.
Biogeochemical cycle or substance turnover or cycling of
substances is a pathway by which a chemical element or
molecule moves through both biotic (biosphere) and abiotic
(lithosphere, atmosphere, and hydrosphere) compartments of
Biogeochemical Cycle- the cycle of matter through the
All matter is conserved
All matter cycles (since none is destroyed)
Found in rocks or buried deep in the ocean in oceanic
found in the atmosphere.( enter through both natural and
- occurs in combination with
several metals such as, PbS
- a brittle yellow, tasteless and
odorless non-metallic element.
10th most abundant element
in the universe,
At room temp. it is a solid
Present in proteins, amino
acids, vitamins, and enzymes,
necessary for plants and
important elements of industrial processes
Sulfur dioxide (SO2) is a bleaching agent and is used to bleach
Sulfur dioxide kills molds and bacteria. (preserve)
Sulfur is found in every living cell (amino acids)
Long used as a medicine ( Brimstone in the old days)
Before the advent of antibiotics in the 1940s, sulfur-containing
drugs-sulfa drugs-were commonly used to treat infectious
component of penicillin-class antibiotics
Medications for dandruff, and warts have this ingredient.
Combining alcohol and sulfur can be used to treat acne and
other skin disorders.
It is also use to make
cements, matches, fireworks,
Powdered sulfur is found in
lotions and skin cream
It includes both atmospheric and terrestrial processes
Hydrogen Sulfide (H2S) is released into the atmosphere (volcanic
eruptions, fossil fuel burning, and the anaerobic decay of sulfur-
containg biological material in swamps, bogs)
Certain marine algae dimethyl sufide + Oxygen in atmosphere =
Volcanic eruptions Sulfur dioxide
Burning of fossil fuels Sulfur dioxide
Sulfur dioxide + Oxygen = Sulfur trioxide, then reacts with tiny water
droplets = Sulfuric Acid
Sulfur Oxides reacts with Ammonia = tiny particles of ammonium
Wind carries Sulfuric acid and ammonium salts which falls to earth in
form of Precipitation.
Plants get sulfur by taking up ions of sulfate salt from the soil.
Animals get sulfur by eating plants and all living things release sulfur
compounds when they decay.
Decomposition releases sulfate salts (SO4 2-), which
can be taken up by plants as well as gaseous hydrogen
Some hydrogen sulfide enters the atmosphere. But
when decay occurs in an oxygem-free environment,
anaerobic bacteria break down hydrogen sulfide and
release sulfur gas (H2)
Oxygen-requiring bacteria can incorporate sulfure into
sulfate salts which can be taken up by plants and enter
the food chain once again.
The remaining sulfur is lost into the oceans depth
combining with iron to form Ferrous Sulfide which is
responsible for the black color of most marine
We burn sulfur containing coal and
oil to produce electricity. We refine
sulfur containing petroleum.
Acid rain is corrosive rain caused by
rainwater falling to the ground
through sulfur dioxide gas, turning
it into weak sulfuric acid, which
causes damage to ecosystems.