redox iron sulfur silica
Download
Skip this Video
Download Presentation
REDOX: IRON, SULFUR, & SILICA

Loading in 2 Seconds...

play fullscreen
1 / 46

REDOX: IRON, SULFUR, & SILICA - PowerPoint PPT Presentation


  • 164 Views
  • Uploaded on

REDOX: IRON, SULFUR, & SILICA. Redox Potential. pE = -log free electrons When corrected to pH 7 (H + = OH - ), called E h When E h positive – oxidizing environment When E h negative – reducing environment. Redox vs. pH. Redox ( mv ) of common liquids. Example of Redox data.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' REDOX: IRON, SULFUR, & SILICA' - herrod-garza


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
redox potential
Redox Potential
  • pE = -log free electrons
  • When corrected to pH 7 (H+ = OH-), called Eh
  • When Eh positive – oxidizing environment
  • When Eh negative – reducing environment
iron oxidizing bacteria
Iron Oxidizing Bacteria
  • Gallionella (an iron-oxidizing bacterium)
  • 4Fe (HCO3)2 + O2 + 6H2O 4Fe (OH)3 + 4H2CO3 + 4CO2 + 58 kcal
ferrobacillus iron bacteria
Ferrobacillus iron bacteria
  • 4FeCO3 + O2+ 6H2O Fe(OH)3 + 4CO2
autotrophic sulfur oxidizing bacteria and iron transformations
Autotrophic Sulfur-Oxidizing Bacteria and Iron Transformations
  • Thiobacillus
  • Some of the reactions that it can mediate
  • FeS2 + 3½O2+H2O FeSO4 + H2SO4
  • 2FeSO4 + ½O2+ H2SO4 Fe2(SO4)3 + H2O
bacterial transformations of sulfur
Bacterial Transformations of Sulfur
  • Sulfate-Reducing Bacteria (heterotrophic and anaerobic)
  • Sulfur-Oxidizing Bacteria
    • Chemosynthetic
    • Pigmented Autotrophic
sulfate reducing bacteria
Sulfate-Reducing Bacteria
  • Ex: Desulfovibrio
  • Heterotrophic and anaerobic
  • H2SO4 + 2(CH2O) 2CO2 2H2O + H2S
  • H2SO4 + 4H2 H2S + 4H2O
chemosynthetic sulfur oxidizing bacteria
Chemosynthetic Sulfur-Oxidizing Bacteria
  • Ex: Beggiatoa
  • Deposit elemental S inside cell
  • H2S + ½O2 S + H2O
  • S + 1½O2 + H2O H2SO4
  • Ex: Thiobacillus
  • Deposit elemental S outside
  • 2Na2S2O3 + O2 2S + 2Na2SO4
green sulfur bacteria
Green Sulfur Bacteria
  • Ex: Chlorobium
  • Uses a pigment similar to chlorophyll
  • CO2 + 2H2SLIGHT Food + H2O + 2S
  • 2CO2 + 2 H2O + H2S LIGHT Food + H2SO4
purple sulfur bacteria
Purple Sulfur Bacteria
  • Ex: Chromatium
  • They deposit sulfur intracellularly
  • Same reactions as Chlorobium
purple non sulfur bacteria
Purple Non-Sulfur Bacteria
  • Ex: Rhodobacter
  • Na2S2O3+2CO2 +3H2O LIGHT Food + Na2SO4 +H2SO4
ad