Biogeochemical Biogeochemical Cycle: SulfurCycle: Sulfur

By Jeff RobergeBy Jeff Roberge

IntroductionIntroduction

Biogeochemical Cycle- the cycle of Biogeochemical Cycle- the cycle of matter through the Earth since:matter through the Earth since:– Earth is a closed systemEarth is a closed system– All matter is conservedAll matter is conserved– All matter cycles (since none is destroyed)All matter cycles (since none is destroyed)

Cycle consists mostly of macronutrientsCycle consists mostly of macronutrients– C, HC, H22O, O, N, P, S, K, Na, Fe, MgO, O, N, P, S, K, Na, Fe, Mg

– But also of Micronutrients (B, Cu, Mo)But also of Micronutrients (B, Cu, Mo)

(“Introduction”)

IntroductionIntroduction

Flow of a chemical through certain Flow of a chemical through certain subdivisionssubdivisions– AtmosphereAtmosphere– LithosphereLithosphere– HydrosphereHydrosphere– BiosphereBiosphere

Usually of ElementsUsually of Elements(Institute)

IntroductionIntroduction

Sulfur- S, it is an elementSulfur- S, it is an element– Naturally found in earthNaturally found in earth– At room temp., it is a solidAt room temp., it is a solid– Present in proteins, amino acids, Present in proteins, amino acids,

vitamins, and enzymes, necessary for vitamins, and enzymes, necessary for plants and animalsplants and animals

– Often reacts with hydrogen creating Often reacts with hydrogen creating hydrogen sulfidehydrogen sulfide Can dissolve in waterCan dissolve in water With metals in water, forms metal With metals in water, forms metal

sulfides;sulfates in airsulfides;sulfates in air

(“Sulfur”)

Sulfur CycleSulfur Cycle

(“Part IV”)

Sulfur CycleSulfur Cycle

In ground: most found in rocks, or salt in In ground: most found in rocks, or salt in earth, or as sediment at bottom of earth, or as sediment at bottom of oceanocean– Found as S, HFound as S, H22S, SOS, SO44

-2-2, (NH, (NH44))22SOSO44

– Enter ground: Plants absorb, or left by acid Enter ground: Plants absorb, or left by acid deposition (fog or precipitation)deposition (fog or precipitation)

– As SOAs SO44-2-2, (NH, (NH44))22SOSO44, and then turn H, and then turn H22S by S by

bacteria, decay, and plant usebacteria, decay, and plant use– Stored: Ground, rock, ocean, somewhat in Stored: Ground, rock, ocean, somewhat in

airair

(“Oxygen”)

Sulfur CycleSulfur Cycle

Sulfur is transferred into biosphere Sulfur is transferred into biosphere then back into ground, or from ground then back into ground, or from ground to atmosphereto atmosphere– Microorganisms turn it into HMicroorganisms turn it into H22S (gas) S (gas)

– Oxidized in atmosphere to SOOxidized in atmosphere to SO22, and then , and then to Hto H22SOSO44 (an acid) with water contact (an acid) with water contact

– Mined ores released to atmosphere in Mined ores released to atmosphere in factories as Hfactories as H22S and SOS and SO22

– Volcanoes and hot springsVolcanoes and hot springs

Sulfur CycleSulfur Cycle Deposited next in waterDeposited next in water

– Through precipitation, dry deposition, leachingThrough precipitation, dry deposition, leaching Rainfall= deposited 73E12 grams sulfur in 1960Rainfall= deposited 73E12 grams sulfur in 1960

– SOSO44-2-2 leaches from soil into ocean as sediment leaches from soil into ocean as sediment

– HH22SOSO44 falls into ocean falls into ocean– Dimethyl Sulfide, carbonyl sulfide (biogenic Dimethyl Sulfide, carbonyl sulfide (biogenic

gases), released by plankton returns back into gases), released by plankton returns back into atmosphere (turns into SOatmosphere (turns into SO22))

– Either re-evaporated, left as sediment for long Either re-evaporated, left as sediment for long time, or deposited on land time, or deposited on land

– 20E12 grams of sulfur a year deposited on land 20E12 grams of sulfur a year deposited on land by seaby sea

– When back on land, cycle repeatsWhen back on land, cycle repeats

Driving ForceDriving Force

Driven by: Driven by: – constant addition of sulfur to environment constant addition of sulfur to environment

by earths interior (geosphere)by earths interior (geosphere)– Human disturbance, addition of sulfur to Human disturbance, addition of sulfur to

atmosphere, (also dug up from atmosphere, (also dug up from environment)environment)

– Natural processes (incl. Biological, Natural processes (incl. Biological, hydrological, due to sun’s energy)hydrological, due to sun’s energy)

– Plant uptake, microbes (Desulfovibrio sp. or Plant uptake, microbes (Desulfovibrio sp. or Desulfotomaculum sp.)Desulfotomaculum sp.)

(“A Black Smoker”)

Percentages of SulfurPercentages of Sulfur

Common in ground as FeSCommon in ground as FeS22

Reservoirs (in 10E18 grams of sulfur):Reservoirs (in 10E18 grams of sulfur):– Oceanic Rocks= 2375 (accurate to 820)Oceanic Rocks= 2375 (accurate to 820)– Sediment= 7800 (accurate to 1700)Sediment= 7800 (accurate to 1700)– Freshwater= .003 (accurate to .002)Freshwater= .003 (accurate to .002)– Ice= .006 (accurate to .002)Ice= .006 (accurate to .002)– Atmosphere= 3.6Atmosphere= 3.6– Sea= 1280 (accurate to 55)Sea= 1280 (accurate to 55)– Organic= .00562Organic= .00562– http://www.soils.wisc.edu/soils/courses/451/20bhttp://www.soils.wisc.edu/soils/courses/451/20b

.%20Global%20S%20cycle.ppt.%20Global%20S%20cycle.ppt

(“Sulfur Cycle”)

Percentages of SulfurPercentages of Sulfur

Most sulfur in particulate formMost sulfur in particulate form– Therefore it is a sedimentary cycleTherefore it is a sedimentary cycle– Very short residence time in atmosphere Very short residence time in atmosphere

(1-2 days)(1-2 days)– Even in atmosphere, found as aerosols Even in atmosphere, found as aerosols

(<1 micrometer), not gas usually(<1 micrometer), not gas usually– In atmosphere, way less than 1%In atmosphere, way less than 1%– Its around .000314 percentIts around .000314 percent– 90-95% SO90-95% SO22 from power plants and from power plants and

factoriesfactories

Human EffectHuman Effect

When mine ores, sulfur/sulfides released When mine ores, sulfur/sulfides released into soilinto soil

Combustion of fossil fuelsCombustion of fossil fuels– Release of SORelease of SO22, causes acid rain, increases , causes acid rain, increases

amount already presentamount already present– 28% of sulfur in rivers from pollution, mining, 28% of sulfur in rivers from pollution, mining,

erosion, etc.erosion, etc.– Help move cycle but also upset balance- too Help move cycle but also upset balance- too

much S means acid rainmuch S means acid rain– Hydrodesulphurization (refine hydrocarbons)- Hydrodesulphurization (refine hydrocarbons)-

surplus of S in Alberta Canadasurplus of S in Alberta Canada

(“Arial”)

(“Sulfur Mining”)

ConclusionConclusion

Sulfur Cycle is important to biological Sulfur Cycle is important to biological and natural processes although and natural processes although human’s role impacts nature in a human’s role impacts nature in a negative waynegative way

Driving force for life, supported first Driving force for life, supported first lifelife

Works Cited“A Black Smoker Venting.” NOAA. 17 Nov. 2008 <http://whyfiles.org/coolimages/index.html%3Fid=1016732011.html>.“Arial Photograph of Eggborough Power Station.” June 2005. 17 Nov. 2008

<http://www.webbaviation.co.uk/industrial/eggborough-power-station.htm>.Institute for Computational Earth System Science. 1 March 2005. University of California. 17 Nov. 2008

<http://www.icess.ucsb.edu/>.“Introduction to Biogeochemical Cycles Chapter 4.” 26 Jan. 1998. University of Colorado at Boulder. 17 Nov. 2008

<http://www.colorado.edu/GeolSci/courses/GEOL1070/chap04/chapter4.html>.“Oxygen Family.” 2008. Advameg Inc. 17 Nov. 2008 <http://www.scienceclarified.com/Oi-Ph/Oxygen-Family.html>.“Part IV of "Matter cycles": The sulfur cycle.” 2006. Lenntech Water Treatment and Air Purification. 17 Nov. 2008

<http://www.lenntech.com/sulfur-cycle.htm>.“Sulfur.” AK Collectibles. 17 Nov. 2008 <http://www.akcollectables.com/store/index.php?page=2&act=viewCat&catId=2>.“Sulfur Cycle.” University of Wisconsin: Department of Soil Science. 17 Nov. 2008 <http://64.233.169.132/search?

q=cache:wQIjeBet-ZEJ:www.soils.wisc.edu/soils/courses/451/20b.%2520Global%2520S%2520cycle.ppt+human+effect+on+sulfur+cycle&hl=en&ct=clnk&cd=2&gl=us>.

“Sulfur Mining.” 2008. Microsoft. 17 Nov. 2008 <http://encarta.msn.com/media_461536436_761568357_-1_1/sulfur_mining.html>.