Flooded Soils: Difference between revisions
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==Introduction== | ==Introduction== | ||
When the pore | When the pore spaces in soils are saturated with water, oxygen dissolved in water is gradually depleted because oxygen is used as terminal electron acceptor for respiration by some aerobes and the facultative anaerobes. This results in anaerobic condition of soils. This anoxic condition can be found in soil aggregates and pollutants plume. Under anoxic condition, some microbes can use alternative electron acceptors such as nitrate, iron, sulfate, and carbon dioxide. | ||
==Process == | ==Process == |
Revision as of 06:38, 6 March 2008
Introduction
When the pore spaces in soils are saturated with water, oxygen dissolved in water is gradually depleted because oxygen is used as terminal electron acceptor for respiration by some aerobes and the facultative anaerobes. This results in anaerobic condition of soils. This anoxic condition can be found in soil aggregates and pollutants plume. Under anoxic condition, some microbes can use alternative electron acceptors such as nitrate, iron, sulfate, and carbon dioxide.
Process
general process
aggregates/polutant plume
Oxidation/reduction(redox) reaction
Electron tower
Change of terminal electrons acceptor with soil depth
Variation of pH and Eh
pH
gradually increasing due to consumpsion of H+ during ananerobic respiration
Eh
decreasing in Eh(V) with soil depth
Exchange of atmospheric gases
Oxygen
Carbon dioxide
Nitrogen
Methane
Solubility/mobility of mineral
Effects on life
Plant nutrient availability
Microorganism activity
WHAT ABOUT IRON AND MANGANESE?-Kate
Key Microorganisms
The role of micoorganisms under flooded soil
nitrate reducing bacteria
Methaneous bacteria
Ion reducing bacteria
Sulfate reducing bacteria
Manganese reducing bacteria
Current Research
References
Edits and Dates
Edited by students of Kate Scow