Ammonia (NH3)
Ammonia (NH3) is a colourless gas with the well-known pungent
odour found in household cleaners. NH3 is produced both by natural
and human sources. Some natural sources of NH3 include the decay
of plant material and animal waste. A small portion is also released during
respiration. In Alberta, the fertilizer industry is the main industrial
source of NH3. The industry produces synthetic NH3
for either direct application to soil as a fertilizer, or as a raw material
for use in the production of other high nitrogen fertilizer products. The
other major source of NH3 is commercial feedlots, specifically
from their large amounts of animal waste.
Monitoring Method
NH3 is monitored continuously by the same principle as NO2. In this method the air sample is split into two pathways. In the first, all NH3 (as well as NO2) in the sample is converted to NO by a catalyst and high temperatures (adding to the NO already in the sample). The concentration is measured by mixing the sample with O3 and utilizing a chemiluminescence reaction to detect the amount of visible light produced. In the second pathway, at a temperature too low to convert NH3, NO2 is reduced to NO by a catalytic converter (adding to the NO already in the sample) and the chemiluminescence process repeated. The difference between the two readings is then calculated to be the concentration of NH3.
Objectives
The Objective for ambient ammonia concentrations is:
- 2.0 ppm as a 1-hour average.
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