sulfur - university of florida · 2 learning objectives identify the forms of s in wetlands sulfur...
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1
Biogeochemistry of WetlandsS i d A li tiS i d A li ti
Institute of Food and Agricultural Sciences (IFAS)
Science and ApplicationsScience and Applications
Wetland Biogeochemistry LaboratorySoil and Water Science Department
SULFUR
6/22/2008 P.W. Inglett 16/22/2008 WBL 16/22/2008 16/22/2008 WBL 1
Instructor :Patrick [email protected]
Soil and Water Science DepartmentUniversity of Florida
Sulfur
IntroductionS Forms, Distribution, Importance
Basic processes of S CyclesExamples of current researchExamples of applications
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Key points learned
2
Learning ObjectivesIdentify the forms of S in wetlands
Sulfur
yUnderstand the importance of S in
wetlands/global processesDefine the major S processes/transformationsUnderstand the importance of microbial activity
in S transformations Understand the potential regulators of S
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processesSee the application of S cycle principles to
understanding natural and man-made ecosystems
Sources of SulfurSources of Sulfur
• Sulfur is a ubiquitous elementSulfur is a ubiquitous element.• Various sulfur compounds are present in:
– The atmosphere– Minerals– Soils– Plant tissue
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– Animal tissue– Microbial biomass– Sediment
3
Reservoirs of Sulfur Reservoirs of Sulfur
•Atmosphere 4.8 x 109 kg•Lithosphere 24.3 x 1018 kg•Hydrosphere
– Sea 1.3 x 1018 kg– Freshwater 3.0 x 1012 kg
•PedosphereS il 2 6 1014 k
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– Soil 2.6 x 1014 kg– Soil Organic matter 0.1 x 1014 kg
•Biosphere 8.0 x 1012 kg
General Forms of Sulfur in the Environment
General Forms of Sulfur in the Environment
• Organic S in plant, animal, and microbial tissue (as i l f i id d i )essential components of amino acids and proteins)
CysteineH3C-S-CH2-CH2-
Methionine
HS-CH2-
OR1-C~S-R2
Thioester
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– Organic sulfur primarily in soil and sediments as humic material (naturally occurring soil and sediment organic matter)
4
General Forms of Sulfur in the Environment
General Forms of Sulfur in the Environment
• Gaseous S compounds (SO2, H2S, DMSO, DMS)
• Oxidized Inorganic S (sulfate, SO42-, is the primary
compound). Seawater contains about 2,700 mg/L (ppm) of sulfate
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• Reduced Inorganic S (elemental sulfur, So, and sulfide, S2-)
General Forms of Sulfur in the Environment
General Forms of Sulfur in the Environment
• MineralsGalena (PbS2) Gypsum (CaSO4)
Jarosite(Fe2S) Barite (BaSO4)
Pyrite (FeS2)
F il F l
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• Fossil Fuels– Petroleum (0.1-10%)
– Coal (1-20%)
5
Oxidation states of selected sulfur compounds
Oxidation states of selected sulfur compounds
• Organic S (R-SH) -2• Sulfide (S2-) -2• Elemental S (S0) 0• Sulfur dioxide (SO2) +4• Sulfite (SO3
-2) +4
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Sulfite (SO3 ) +4• Sulfate (SO4
2-) +6
Global Sulfur CycleGlobal Sulfur Cycle
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6
1. Dissimilatory sulfate reduction
Sulfur Cycling ProcessesSulfur Cycling Processes
2. Assimilatory sulfate reduction
3. Desulfurylation
4. Sulfide oxidation
5. Sulfur oxidation
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6. Dissimilatory So reduction
So
Sulfur CycleSulfur Cycle
45
SO42- S2-
SH groupsof protein
SH groups
AerobicAerobic
Anaerobic1
2 3
2 3
5
AerobicAerobic
Anaerobic
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So
SH groupsof protein 45
6
Anaerobic
7
Distribution of sulfur in soilsDistribution of sulfur in soils
Organic sulfur [93%]Organic sulfur [93%]– Carbon-bonded sulfur (cysteine and methionine) 41%
– Non-carbon-bonded sulfur (ester sulfates) 52%
Inorganic sulfur [7%]– Adsorbed + soluble sulfates 6%
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Adsorbed + soluble sulfates 6%
– Inorganic compounds less oxidized than sulfates and reduced sulfur compounds (e.g. sulfides) 1%
20Freshwater
Organic Sulfur FormsOrganic Sulfur Forms
15
10
5Sulfu
r, g/
kg
Freshwater
Brackish
Salt
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0
S
Ester C-S Total
Organic Geochemistry vol. 18, no. 4, pp. 489-500, 1992
8
Freshwater400 4
Inorganic Sulfur FormsInorganic Sulfur Forms
Freshwater
Brackish
Salt
300
200
100
3
2
1ulfu
r, m
g/kg
Sulfu
r, g/
kgSu
lfur,
g/kg
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0 0FeS So FeS2 HCl
Su
SS
Krairapanond et al. 1992. Organic Geochemistry 18: 489-500.
Organic S HydrolysisOrganic S Hydrolysis
R - S-H2 + H2O R-OH + H2S
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SulfohydrolaseR S H2 + H2O R OH + H2SThiol
9
Assimilatory Sulfate Reduction• Bacteria fungi algae and plants
Sulfur – Organism GroupsSulfur – Organism Groups
• Bacteria, fungi, algae, and plants
Dissimilatory Sulfate Reduction• Hetrerotrophs
Desulfovibrio, Desulfotomaculum, Desulfobacter, Desulfuromonas
Sulfide Oxidation
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Sulfide Oxidation• Phototrophs: Chlorobium, Chromatium
• Chemolithoautotrophs: Thiobacillus, Beggiatoa
Sulfate Reducing Bacteria: SRB(habitats)
Sulfate Reducing Bacteria: SRB(habitats)
Desulfovibrio - found in water-logged soils.
Desulfotomaculum - spoilage of canned foods.
Desulfomonas - found in intestines.
Archaeglobus - a thermophilic Archea whose optimal growth temperature is 83oC
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growth temperature is 83 C.
10
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Sulfate ReductionSulfate Reduction
DepositionSO4
2-
AEROBICAEROBIC
Adsorbed SO 2ReductionReduction
Tidal Exchange
SO42-
SO42-
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ANAEROBIC
SO42-
MicrobialBiomass-S
S2-ReductionReduction
SO42-So
11
Glucose OxidationGlucose Oxidation
Oxidation – Reduction ReactionkJ/mol
GlucoseGlucose
C6H12O6 + 6O2 = 6CO2 + 6H2O 2,880
5C6H12O6 + 24NO3- + 24H+ = 30CO2 + 12N2 +42H2O 2, 712
C6H12O6 + 12MnO2 + 24H+ = 6CO2 + 12Mn2+ + 18H2O 1,920
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C6H12O6 + 24Fe(OH)3 + 48H+ = 6CO2 + 24 Fe2+ +66H2O 432
C6H12O6 + 3SO42- = 6CO2 + 3S2- + 6H2O 381
120
Oxygen Equivalents-Energy Yield from Glucose
Oxygen Equivalents-Energy Yield from Glucose
40
60
80
100
erob
ic E
nerg
y Yi
eld
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0
20
O2 NO3- MnO2 Fe(OH)3 SO4
2-SO42-
% o
f Ae
Electron Acceptors
12
SO42- S2-SO42- S2- Mn4+ Mn2+ O2 H2O
Oxidation-ReductionOxidation-Reduction
CO2 CH4 Fe3+ Fe2+ NO3- N2
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-200 -100 0 +100 +200 +300 +400Redox Potential, mV (at pH 7)Redox Potential, mV (at pH 7)
Sequential Reduction of Sequential Reduction of Electron Acceptors Electron Acceptors
Sequential Reduction of Sequential Reduction of Electron Acceptors Electron Acceptors
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13
WATERWATER
SOILSOIL
Redox Zones With DepthRedox Zones With DepthRedox Zones With DepthRedox Zones With Depth
Oxygen Reduction Zone AerobicAerobicSOILSOIL Oxygen Reduction ZoneEh = > 300 mV
Nitrate Reduction ZoneMn4+ Reduction ZoneEh = 100 to 300 mVFe3+ Reduction ZoneEh = -100 to 100 mV
I
II
III
FacultativeFacultative
Dep
thD
epth
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Sulfate Reduction ZoneEh = -200 to -100 mV
MethanogenesisEh = < -200 mV
IV
V
AnaerobicAnaerobic
DD
1000
800
Redox Potential and pHRedox Potential and pHRedox Potential and pHRedox Potential and pH
600
400200
0
-200
E h[m
V]
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0 2 4 6 8 10 12
-200
-400
-600
pHBaas Becking et al.
14
Microbial Activity[Site: Water Conservation 2A]
Microbial Activity[Site: Water Conservation 2A]
50
60on
s on
s y = 0.33x + 1.3r2 = 0 88; n = 24
20
30
40
50
e re
duci
ng c
ondi
tie
redu
cing
con
diti
[mg
kg[m
g kg
--11ho
urho
ur--11
]]r 0.88; n 24
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0
10
10 20 30 40 50 60
Sul
fate
Sul
fate
AerobicAerobic [mg kg[mg kg--11 hourhour--11]]
0
Detrital MatterEnzymeHydrolysisComplex Polymers
Cellulose, Hemicellulose,Monomers
Sugars, Amino AcidsF tt A id
Sulfate RespirationSulfate Respiration
Glucose
PyruvateGlycolysis
Substrate level TCA Cycle
Oxidative phosphorylation
CO
Proteins, Lipids, Waxes, Lignin Fatty Acids
Uptake
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Products:CO2, H2O, S2-, Nutrients
phosphorylation AcetateCO2
ATP
SO42- + e- Organic Acids
[acetate, propionate, butyrate, lactate, alcohols, H2, and CO2]
LactateUptake
[Sulfate Reducing Bacterial Cell] [Fermenting Bacterial Cell]
Substrate level phosphorylation
15
Electron donors used during sulfate reduction
Electron donors used during sulfate reduction
• SRB lack enzymes necessary for complex carbon assimilation
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Electron donors used during sulfate reduction
Electron donors used during sulfate reduction
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16
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Decreasing energy
yield
Electron DonorsElectron Donors
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Capone and Kiene. 1988. Limnol Oceanogr, 33: 725-749.
17
Activity [nmol/g per day]
Sulfate Reduction RatesSulfate Reduction Rates
[ g p y]
Low carbon wetland 23
Peaty wetland 130
Oligotrophic lake 707
Eutrophic lake 1,224
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Marine and salt-marsh 744-24,000
Respiration [g C/m2 year] Sapelo Island Sippewissett Sapelo Island
[GA] [MA] (199 )
Salt MarshesSalt Marshes
[GA] [MA] (1997)
Aerobic respiration 390 390Denitrification 10 3Mn and Fe reduction ND NDSulfate reduction 850 1,800 2,000Methanogenesis 40 1-8
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Methanogenesis 40 1 8
~65%~65% ~82%~82% ~69-87%~69-87%S Respiration
18
Sulfate RespirationSulfate Respiration
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Capone and Kiene. 1988. Limnol Oceanogr, 33: 725-749.
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Capone and Kiene. 1988. Limnol Oceanogr, 33: 725-749.
19
Seasonal EffectsSeasonal Effects
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Jorgensen, 1977. Marine Biology 41:7-17.
Seasonal EffectsSpartina alterniflora marshSeasonal EffectsSpartina alterniflora marsh
Great Sippewissett Marsh
0 50.5
0.4
0.3
0.2
Mol
es S
O42-
m-2
d-1
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J J JMF MA A S O N D
0.1
0.0
M
MonthsHowarth and Giblin, 1983. Limnol and Oceanogr, 28:70-82.
20
Seasonal EffectsSpartina alterniflora marshSeasonal EffectsSpartina alterniflora marsh
0 50.5
0.4
0.3
0.2
Mol
es S
O42-
m-2
d-1
Mol
es O
2m
-2d-
1
0.01
0.03
0.02
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0.1
0.0
M M-5 20 2550 1510 30
Temp (C)-5 20 2550 1510 30
Temp (C)
Howarth and Teal. 1979. Limnol and Oceanogr, 24: 999-1013.
Regulators of Sulfate ReductionRegulators of Sulfate Reduction
P f l t t ith hi h• Presence of electron acceptor with higher reduction potentials
• Oxygen is toxic to sulfate reducers• Sulfate concentration
– Freshwater (< 0.1 mM)– Marine (20-30 mM)
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• Substrate/Electron Donor• Temperature• Microbial populations
21
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Decreasing energy
yield
Sulfidogenic aggregate Sulfidogenic/Methanogenic aggregate
Anaerobic Sludge Reactor(FISH)
Anaerobic Sludge Reactor(FISH)
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Appl Environ Microbiol. 1999 October; 65(10): 4618–4629. SRB Probe Archeal Probe
22
Competition With MethanogensCompetition With Methanogens
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XXXX
Sulfate Reducers vs MethanogensSulfate Reducers vs Methanogens
Sulfate reducersVmax
V
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Methanogens
Vmax
Km Km
[Substrate]
V = [Vmax S]/Km + S
23
0.6CH
Sulfate ReductionTypical Lake Sediments
Sulfate ReductionTypical Lake Sediments
0.2
0.4
mM
CH
4
mM
SO
42-
20
10
CH4
SO42-
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1000 20 40 60 80
Daysfrom Jorgensen: in Microbial Geochemistry. Krumbein, ed: 1983 Blackwell.
Sulfate ReductionTypical Lake Sediments
Sulfate ReductionTypical Lake Sediments
12
8
mM SO42-
0.20.10
mM SO42-
2010
SO 28
4
0
8
cm
CH4
SO42-
4
0.5
1.0
1.5 CH4
SO42-
m
6/22/2008 P.W. Inglett 46from Jorgensen: in Microbial Geochemistry. Krumbein, ed: 1983 Blackwell.
12
1 2mM CH4
2.0
0.5 1.0mM CH4
FreshwaterFreshwater MarineMarine
24
Sulfate ReductionCattail Marsh – Sunnyhill Farm Wetland
Sulfate ReductionCattail Marsh – Sunnyhill Farm Wetland
0 5 10 1510
W t
CH4 (mg L-1)
0
-10
Dep
th (c
m)
Water
Soil
CH4
SO42-
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0 20 40 60 80 100-30
-20
SO42- (mg L-1)
Sulfate ReductionSulfate Reduction
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Iversen and Jorgensen. 1985. Limnol Oceanogr, 30: 944-955.
25
Sulfur EmissionsSulfur Emissions
H2S
AEROBICAEROBICOrg-SMineralization
SO 2
H2SDMS
O S S2
Mineralization ReductionReduction
2DMS
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ANAEROBIC
SO42-Org-S S2- So
Gaseous S EmissionsGaseous S Emissions
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26
SALT BRACKISH FRESH
Gaseous SpeciationGaseous SpeciationDeLaune et al. 2001
H2SH3C-S-CH3CO-S
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ug S m-2 hr-1
Sulfide FormationSulfide Formation
H2S
AEROBICAEROBICOrg-SMineralization
SO 2
H2SDMS
O S S2
Mineralization ReductionReduction
2DMS
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ANAEROBIC
SO42-Org-S S2- So
27
Sulfide SpeciationSulfide Speciation
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Problems With Hydrogen SulfideProblems With Hydrogen Sulfide
• Malodorous (rotten egg smell)
• Acidic (corrosion/fouling)
• Toxic (reactive with metalloenzyme systems)
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metalloenzyme systems)
28
Sulfide ToxicityTall vs. Short Spartina alterniflora
Sulfide ToxicityTall vs. Short Spartina alterniflora
Tall FormTall Form
Short FormShort Form
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29
Sapelo Island MarshTall vs. Short Spartina alternifloraTall vs. Short Spartina alterniflora
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CreekCreek TallTall ShortShortKostka et al., 2002. Biogeochemistry 60:49-76.
Sulfide ToxicityTall vs. Short Spartina alterniflora
Sulfide ToxicityTall vs. Short Spartina alterniflora
Lower VmaxHigher Vmax
NH4+ UptakeNH4+ Uptake
MHT
Higher KmLower Km
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MLT
Inc. Flood Frequency, Pore Water Turnover
Inc. NH4+, S2-, and Salt Concentrations
30
Sulfide PrecipitationSulfide Precipitation
AEROBICAEROBIC
SO 2S2ReductionReduction
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ANAEROBIC
SO42-S2- So
FeS2
Me+-S
Iron and Sulfide InteractionsIron and Sulfide Interactions
2F OOH H S S 2F 2+ 4OH2FeOOH + H2S = So + 2Fe2+ + 4OH-
Fe2+ + H2S = FeS + 2H+
FeS + So = FeS2
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Acid Volatile S (AVS)
Chromium Reducible S (CRS)
31
Pyrite FramboidsPyrite Framboids
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Pyrite FormationPyrite Formation
Fe Oxides
Monosulfides (AVS)
FeS
ΣH2SS0
Intermediate
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FeS2Pyrite (CRS)
Redox S
Sulfate Reduction
32
SolidSolid--FeFe AVSAVS CRSCRS
Pyrite FormationSapelo Island Marsh
Pyrite FormationSapelo Island Marsh
CreekTallShort
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Kostka et al., 2002. Biogeochemistry 60:49-76.
ZnSZnS
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33
Metal Sulfide Solubility-Uptake by Rice Plant
Metal Sulfide Solubility-Uptake by Rice Plant
5
4d 35
S Na2S
4
3
2
1
% U
ptak
e of
add
e
MnSFeS ZnS C S H S
6/22/2008 P.W. Inglett 65Engler and Patrick, 1981
0
%
100 10-10 10-20 10-30 10-40 10-50
FeS ZnS CuS HgS
Solubility Product (Ksp)
Metal Sulfide SolubilityMetal Sulfide Solubility
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Yu et al. 2001. Wat Res. 35:4086-4094.
34
Sulfur OxidationSulfur Oxidation
AEROBICAEROBICSO42-So
H2SDMS
S2
Oxidation Oxidation
Reduction
Tidal Exchange
SO42-
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ANAEROBIC
S2- So
Sulfide OxidationSulfide Oxidation
2H2S + O2 = 2So + 2H2O204 kJ/ ti-204 kJ/reaction
2So + 3O2 + 2H2O = 2SO42- + 4H+
-583 kJ/reaction
H2S + 2O2 = SO42- + 2H+
-786 kJ/reaction
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86 J/ eact o
H2S So SO32- SO4
2-
35
Sulfur Cycling Cyanobacterial Mat Sediments
Sulfur Cycling Cyanobacterial Mat Sediments
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Sulfur Cycling Cyanobacterial Mat Sediments
Sulfur Cycling Cyanobacterial Mat Sediments
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Aphanothece Diatoms
Phormidium, Lyngbya
Chromatium salexigens Thiocapsa halophila.
SurfaceSurface Green LayerGreen Layer Red LayerRed Layer
36
Oxidation-ReductionOxidation-ReductionSoil-floodwater InterfaceSoil-floodwater Interface
O2
SO42- H2S + O2
Floodwater
Aerobic soil
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H2SAnaerobic soil
SO42-
Sulfur Cycling Salt Marsh Surface Sediments
Sulfur Cycling Salt Marsh Surface Sediments
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37
Oxidation-ReductionOxidation-Reduction
Root- Soil InterfaceRoot- Soil Interface
AEROBICAEROBIC
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ANAEROBIC
Oxidation-ReductionInfaunal Burrows
Oxidation-ReductionInfaunal Burrows
Uca spp.
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38
Oxidation-ReductionInfaunal Burrows
Oxidation-ReductionInfaunal Burrows
ca. 12” Deepca. 12” Deep
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39
Sulfur CycleSulfur Cycle
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from Jorgensen: in Microbial Geochemistry. Krumbein, ed: 1983 Blackwell.
Rates = mmol/m2 day
FeS2 + 3.5O2 + H2O = Fe2+ + 2SO42- + 2H+
Fe2+ + 0.25O2 + H+ = Fe3+ + 0.5H2O
Pyrite OxidationPyrite Oxidation
(1) FeS2 + 3.75O2 + 0.5H2O = Fe3+ + 2SO42- + H+
(2) FeS2 + 14Fe3++ 8H2O = 15Fe2+ + 2SO42- + 16H+
Fe2+ SO42- + H+
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Fe2+
Fe3+ FeS2
O2Slow (at low pH)
Biological[Thiobacillus ferrooxidans]
FastChemical/Biological
SO4 H
40
Drainage Effects on Acid Sulfate SoilsDrainage Effects on Acid Sulfate Soils
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Acid Sulfate SoilsAcid Sulfate Soils
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41
Acid Mine DrainageAcid Mine Drainage
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Sulfur Cycling in WetlandsSulfur Cycling in WetlandsPlant Biomass-S
DepositionSO4
2-
AEROBICAEROBICOrg-S
Adsorbed SO4
2-
Litterfall
Mineralization .
SO 2
SO42-So
H2SDMS
S2
Mineralization
Oxidation Oxidation
ReductionReduction
Tidal ExchangeH2SDMS
SO42-
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ANAEROBIC
4SO42-
MicrobialBiomass-S
Org-S S2- So
SO42-
FeS2
Me+-S
S2-
42
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Hg MethylationHg Methylation
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Gilmore et al., 1992. Env Sci Tech. 26:2281-2287.
43
Hg MethylationHg Methylation
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Gilmore et al., 1992
Hg MethylationHg Methylation
Desulfobacteriaceae
Lactate
Acetate
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King et al., 2000. Applied and Environmental Microbiology, June 2000, p. 2430-2437.
Control
44
Hg MethylationHg Methylation
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Methylmercury in Floating Periphyton
All Cycles 1995-1996
Periphyton Delta 32S
September 1996
ug/kg
>6
4
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2
0
Kendall et al., http://sofia.usgs.gov/publications/posters/
45
S2-
Hg MethylationHg Methylation
S0
HgS0HgS0
HgHg H3C-HgH3C-Hg
SRBSRB??
S0
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SO42-
HgS2HgS2
Importance of Sulfur in WetlandsImportance of Sulfur in Wetlands
• Source of nutrient
• Source of energy
• Role in decomposition of organic matter
• Adverse effects of sulfide on plant growth
• Immobilization of toxic metals
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• Contribution to acid development (oxidation)
• Role in methylation of Hg