Electron Donor

Definitions

Electron Donor - "The compound that donates electrons (and therefore is oxidized). In bioremediation the organic contaminant often serves as an electron donor." - National Research Council, 1993

Electron Donor - "A chemical entity that donates electrons to another compound. It is an oxidizing agent that, by virtue of its accepting electrons, is itself reduced in the process." - U.S. Environmental Protection Agency, 2009

Electron Donor - "Suitable electron donors (such as organic compounds) together with electron acceptors (such as O₂, nitrate, ferric iron, sulfate, CO₂, or certain types of simple organic compounds) are required for the generation of energy. N [nitrogen], P [phosphorus], and S [sulfur] sources may be organic or inorganic, with some microorganisms able to use either while others are more restricted." - Pankow and Cherry, 1996

Electron Donor - "Redox reactions involve the transfer of electrons from a donor molecule to an acceptor molecule. The electron donor (D) loses n electrons and is oxidized: D=Dⁿ⁺+ne^-. The electron acceptor (A) gains the n electrons and is reduced: A+ne^-=A^n-. The term redox is short-hand for reduction and oxidation. It underscores that reduction of an acceptor and oxidation of a donor always occur together so that all electrons leaving the donor are taken up by the acceptor: D+A=Dⁿ⁺+A^n-." - National Reseach Council, 1993

Text in brackets ("[text]") are added by the editor.

Related Definitions

Biodegradation

Electron Acceptor

Aerobic

Aerobic Biodegradation

Anaerobic

Anaerobic Biodegradation

Anoxic

Biotransformation

Natural Attenuation

USGS Information on Biodegradation

• Crosscutting Topics, Toxic Substances Hydrology (Toxics) Program
• Natural Attenuation
• Contaminant Plume Geochemistry and Microbiology
• Toxics Program Biodegradation Investigations
• Biodegradation of Emerging Contaminants
• Fate of Landfill Leachate, Norman Municipal Landfill, Norman, Oklahoma
• Sewage Contamination in Sand and Gravel Aquifers, Cape Cod, Massachusetts
• Processes that Control the Natural Attenuation of Chlorinated Solvents
• Microbial Degradation of Chloroethenes in Groundwater Systems
• Application of Molecular Methods in Microbial Ecology to Understand the Natural Attenuation of Chlorinated Solvents
• Processes Affecting the Natural Attenuation of Fuels in Groundwater
• Crude Oil -- Bemidji, Minnesota
• Fuel Oxygenates -- Laurel Bay, South Carolina
• Gasoline -- Galloway Township, New Jersey [Completed]
• Produced Water -- Osage-Skiatook Petroleum Environmental Research Project, Oklahoma [Completed]
• Creosote Waste in Ground Water, Pensacola, Florida [Completed]
• Toxics Program Remediation Related Activities
• Biodegradation of Charcoal Production Wastes, Kingsford, Mich.
• Quantifying Subsurface Biodegredation, Norman Municipal Landfill, Norman, Okla.
• Can Trees Clean Up Ground Water? Phytoremediation of Trichloroethene-Contaminated Ground Water at Air Force Plant 4, Fort Worth, Tex.
• Natural Attenuation of Wood Preservatives in Ground Water, Pensacola, Fla.
• Natural Aquifer Restoration, Massachusetts Military Reservation, Cape Cod, Mass.
• RDX Biodegradation Assessment, Naval Submarine Base Bangor, Wash.
• Oxygen-Release Compound Remediation Tests, Laurel Bay, S.C.
• Quantifying Natural Attenuation at the Plume Scale, Galloway Township, N.J. and Laurel Bay, S.C.
• USGS National Research Program Biodegradation Related Projects
• Biogeochemistry of Carbon and Nitrogen in Aquatic Environments
• Chemical Transformations in Water Reclamation and Reuse
• Microbial Biogeochemistry of Aquatic Environments
• Multiphase Contaminant Transport, Reaction and Biodegradation
• Organic Compounds in Near-Surface Environments: Understanding Fate in a Changing Biogeochemical Landscape
• Partitioning of Solutes between Solid and Aqueous Phases
• Subsurface Microbiology Research - Bacteria, Contaminant Interactions
• Bioremediation Activities, USGS Microbiology Research
• Geochemical and Microbial Evidence of Fuel Biodegradation in a Contaminated Karst Aquifer in Southern Kentucky, June 1999

Related Headlines

• Complex Mixture of Contaminants Persists in Streams Miles from the Source
• Natural Attenuation Accelerates Pump-and-Treat Cleanup of TCE in Fractured Rock
• Organic Contaminants Stored on Sediments Can Slow Down Groundwater Restoration
• Sometimes the Question Is «Who Isn't Living There?»
• Do Natural Processes Mitigate Contamination from Landfill Leachate?
• Hormones Degrade in the Environment!
• Detergents in Streams May Just Disappear
• Hydrogen Measured in a New Test for Determining Subsurface Microbiological Activity at Contamination Sites
• New Report Presents a Framework for Assessing the Sustainability of Monitored Natural Attenuation
• RDX Biodegradation Under Metal-Reducing Conditions
• New Information on the Long-Term Fate of Ammonium in Ground Water
• Microorganisms Degrade MTBE Even at Winter Ground-Water Temperatures
• Does NDMA Biodegrade at Ground-Water Recharge Facilities?
• Ground-Water Recharge Affects Fate of Petroleum Contaminant Plumes
• History and Ecology of Chloroethene Biodegradation--A Review
• Using Oxygen to Enhance Biodegradation of Contaminants -- Lessons Learned
• USGS Scientists Contribute to the Landmark "Treatise on Geochemistry"
• A Unique Approach to Evaluating Natural Attenuation is Applied Worldwide
• Landmark Book Published on the Fate of Contaminants in the Environment: Partition and Adsorption of Organic Contaminants in Environmental Systems
• Using Oxygen to Clean Up Ground-Water Contamination
• MTBE Can Degrade Naturally Without Oxygen
• How Do You Clean Up Gasoline Spills Naturally?
• Relying on Nature to Clean Up Contaminated Ground Water
• MTBE Biodegrades Naturally in Stream Sediments
• Natural Attenuation for Groundwater Remediation
• Can a Sewage-Contaminated Aquifer Naturally Clean Itself?
• Natural Attenuation of MTBE at Laurel Bay, South Carolina

Other Information on Biodegradation

• U.S. Environmental Protection Agency
  • Natural Attenuation, CLU-IN, Office of Superfund Remediation and Technology Innovation
  • Monitored Natural Attenuation (MNA), Office of Research and Development
  • Commonly Asked Questions Regarding the Use of Natural Attenuation for Petroleum Contaminated Sites at Federal Facilities
  • Commonly Asked Questions Regarding the Use of Natural Attenuation for Chlorinated Solvent Spills at Federal Facilities
• National Research Council Reports
• Natural Attenuation for Groundwater Remediation
• In Situ Bioremediation: When Does it Work?
• Alternatives for Ground Water Cleanup
• Environmental Inquiry - Biodegradation, Cornell University and Penn State University
• Biocatalysis/Biodegradation Database, University of Minnesota

References

National Research Council, 1993, In situ bioremediation--When does it work?: Washington, D.C., National Academies Press, 224 p.

Pankow, J.F., and Cherry, J.A., 1996, Dense chlorinated solvents and other DNAPLs in groundwater--History, behavior, and remediation: Portland, Oregon, Waterloo Press, 522 p.

U.S. Environmental Protection Agency, 2009, Glossary of technical terms: U.S. Environmental Protection Agency, access date June 7, 2011.