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Physics and Chemistry of Water

  1. Robert M. Burgess

Published Online: 15 APR 2005

DOI: 10.1002/047147844X.pc41

Water Encyclopedia

Water Encyclopedia

How to Cite

Burgess, R. M. 2005. Ammonia. Water Encyclopedia. 4:390–394.

Author Information

  1. U.S. Environmental Protection Agency, Narragansett, Rhode Island

Publication History

  1. Published Online: 15 APR 2005


Ammonia is a primary breakdown product of nitrogen-containing organic matter in aquatic environments. Because a great deal of organic matter and waste is introduced into the hydrologic cycle by natural and anthropogenic processes, ammonia can be found in aquatic environments, especially those exposed to large amounts of human or domestic animal wastes. Ammonia is also of great importance in understanding the global cycling of several key elements, including nitrogen and carbon. Ammonia is one of the compound uniquely critical to life which when not present in adequate amounts in aquatic environments can be associated with negative biological effects and when in excess can result in adverse ecological and toxic effects. When insufficient ammonia is available to plants, which assimilate ammonia to grow, they may experience metabolic problems due to nutrient limitations. Conversely, excess ammonia is commonly associated with eutrophic conditions in water bodies and toxicity to some organisms. Further, nitrous oxide (N2O) a molecule involved in the environmental cycling of ammonia is considered a potential ‘greenhouse gas’ which can also destroy stratospheric ozone. Because of these adverse effects, ammonia is frequently considered a pollutant in aquatic systems.


  • ammonia;
  • ammonium;
  • nitrogen;
  • cycling;
  • organic matter;
  • greenhouse gas;
  • ammon;
  • pH;
  • fixation;
  • ammonification;
  • nitrification;
  • denitrification;
  • domestic animals;
  • toxicity;
  • eutrophication