Biogeochemical Cycle: Sulfur By Jeff Roberge

Introduction Biogeochemical Cycle- the cycle of matter through the Earth since: Earth is a closed system All matter is conserved All matter cycles (since none is destroyed) Cycle consists mostly of macronutrients C, H2O, O, N, P, S, K, Na, Fe, Mg But also of Micronutrients (B, Cu, Mo) (“Introduction”)

Introduction Flow of a chemical through certain subdivisions Atmosphere Lithosphere Hydrosphere Biosphere Usually of Elements (Institute)

Introduction Sulfur- S, it is an element Naturally found in earth At room temp., it is a solid Present in proteins, amino acids, vitamins, and enzymes, necessary for plants and animals Often reacts with hydrogen creating hydrogen sulfide Can dissolve in water With metals in water, forms metal sulfides;sulfates in air (“Sulfur”)

Sulfur Cycle (“Part IV”)

Sulfur Cycle In ground: most found in rocks, or salt in earth, or as sediment at bottom of ocean Found as S, H2S, SO4-2, (NH4)2SO4 Enter ground: Plants absorb, or left by acid deposition (fog or precipitation) As SO4-2, (NH4)2SO4, and then turn H2S by bacteria, decay, and plant use Stored: Ground, rock, ocean, somewhat in air (“Oxygen”)

Sulfur Cycle Sulfur is transferred into biosphere then back into ground, or from ground to atmosphere Microorganisms turn it into H2S (gas) Oxidized in atmosphere to SO2, and then to H2SO4 (an acid) with water contact Mined ores released to atmosphere in factories as H2S and SO2 Volcanoes and hot springs

Sulfur Cycle Deposited next in water Through precipitation, dry deposition, leaching Rainfall= deposited 73E12 grams sulfur in 1960 SO4-2 leaches from soil into ocean as sediment H2SO4 falls into ocean Dimethyl Sulfide, carbonyl sulfide (biogenic gases), released by plankton returns back into atmosphere (turns into SO2) Either re-evaporated, left as sediment for long time, or deposited on land 20E12 grams of sulfur a year deposited on land by sea When back on land, cycle repeats

Driving Force Driven by: constant addition of sulfur to environment by earths interior (geosphere) Human disturbance, addition of sulfur to atmosphere, (also dug up from environment) Natural processes (incl. Biological, hydrological, due to sun’s energy) Plant uptake, microbes (Desulfovibrio sp. or Desulfotomaculum sp.) (“A Black Smoker”)

Percentages of Sulfur Common in ground as FeS2 Reservoirs (in 10E18 grams of sulfur): Oceanic Rocks= 2375 (accurate to 820) Sediment= 7800 (accurate to 1700) Freshwater= .003 (accurate to .002) Ice= .006 (accurate to .002) Atmosphere= 3.6 Sea= 1280 (accurate to 55) Organic= .00562 http://www.soils.wisc.edu/soils/courses/451/20b.%20Global%20S%20cycle.ppt (“Sulfur Cycle”)

Percentages of Sulfur Most sulfur in particulate form Therefore it is a sedimentary cycle Very short residence time in atmosphere (1-2 days) Even in atmosphere, found as aerosols (<1 micrometer), not gas usually In atmosphere, way less than 1% Its around .000314 percent 90-95% SO2 from power plants and factories

Human Effect When mine ores, sulfur/sulfides released into soil Combustion of fossil fuels Release of SO2, causes acid rain, increases amount already present 28% of sulfur in rivers from pollution, mining, erosion, etc. Help move cycle but also upset balance- too much S means acid rain Hydrodesulphurization (refine hydrocarbons)- surplus of S in Alberta Canada (“Arial”) (“Sulfur Mining”)

Conclusion Sulfur Cycle is important to biological and natural processes although human’s role impacts nature in a negative way Driving force for life, supported first life

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>.