What is ammonia?
Ammonia (NH3) is a colorless gas, lighter than air, highly water-soluble, and has a sharp, pungent odor that is detectable from 5 to 18 ppm. NH3 is attributed to the effects of acidification on the environment. NH3 and chemical combinations (NHx) are important components responsible for soil acidification in addition to sulfur compounds (SOx), nitrogen oxides, and volatile organic components.

What are the problems related to ammonia emissions ?
NH3 may cause several ecological problems in the environment:

  • The inputs of nitrogen may lead to considerable changes in plant communities with the result that plants, which prefer low nitrogen soils disappear and there is an increase in nitrogen indicator plants.
  • Acidification of soil with low buffer capacity may occur after nitrification of the nitrogen added. A falling pH leads to the dissolution of toxic soil constituents such as aluminum ions, and to the leaching of nutrients and aluminum into the groundwater.
  • The natural capability of forest soil to take up methane (CH4) decreases by NH3 deposition, thus increasing the concentration of the greenhouse gas in the atmosphere.
  • Surface waters may be affected by eutrophication and acidification.
  • NH3 depositions on buildings will promote bacterial growth, which contributes substantially to weathering and corrosion damage of the buildings.
 
 
Emissions of ammonia play an important role in the formation of particulate matter (a mixture of solid particles and liquid droplets) in the atmosphere. Under typical atmospheric conditions, ammonia reacts with gaseous emissions of sulfur dioxide and nitrogen oxides to form sulfate and nitrate fractions of fine particles. Fine particles are defined as those having an aerodynamic diameter of less than 2.5 mm. This is approximately 1/30 the size of a human hair. Elevated levels of fine particles (PM2.5) are of concern because they are risk to both human health and the environment. More detailed information on PM 2.5 is available here.

The consequences of NH3 emission are primarily of an ecological nature and must be considered on a long-term basis in terms of minimizing the environmental damage caused by NH3 emission from agricultural production.

How is NH3 released in the environment from animal operations?

Ammonia release from animal sources is prevalent due to the often-inefficient conversion of feed nitrogen to animal product. As a result, high concentrations of nitrogen are excreted in the urine of pigs and cattle and in the uric acid excreted by poultry. A more detailed description of all the processes involved can be found in the White Paper on Ammonia Emissions from Animal Feeding Operations.

What are typical NH3 levels in animal buildings?

Typical NH3 levels in well-ventilated confinement buildings are 5 to 10 ppm with liquid manure systems and 10 to 20 ppm where manure and urine are deposited on solid floors, especially poultry units. Ammonia levels in built-up litter broiler houses and layer houses with manure storages may be higher, but actual levels depend so much on individual manure management and handling practices. The permissible exposure limit (PEL) for ammonia is 25 ppm by ACGIH, AIHA (American Industrial Hygiene Association) and NIOSH, but 50 ppm by OSHA.


Information compiled by José R. Bicudo.

Updated 07/14/2003
This website is hosted and maintained by the Biosystems and Agricultural Engineering - University of Kentucky
Please direct questions and comments regarding this website to BAE Webmaster
http://www.bae.uky.edu