What is the Difference Between Ammonia and Ammoniacal Nitrogen?

The key difference between ammonia and ammoniacal nitrogen lies in their chemical composition and the forms they take. Ammonia is an inorganic compound with the chemical formula NH3, while ammoniacal nitrogen is a measure of the amount of ammonia in a sample and refers to all forms of ammonia, including ammonia (NH3), ammonium (NH4+), nitrogen gas (N2), nitrates (NO3–), nitrites (NO2–), and organic nitrogen such as proteins and DNA.

• Ammonia (NH3): A gaseous compound with a characteristic pungent odor, it is toxic at high concentrations and is a common toxic pollutant in waste products such as sewage and manure.
• Ammoniacal Nitrogen (NH3-N): A measure of the amount of ammonia in a sample, it is denoted as NH3-N, and the unit of measurement is mg/L. It measures all forms of ammonia, including ammonia (NH3), ammonium (NH4+), nitrogen gas (N2), nitrates (NO3–), nitrites (NO2–), and organic nitrogen such as proteins and DNA.

Both ammonia and ammoniacal nitrogen are involved in the nitrogen cycle, which involves the oxidation and reduction of nitrogen. Ammoniacal nitrogen is used to measure the health of natural water bodies because ammonia can directly poison aquatic life at high concentrations.

Comparative Table: Ammonia vs Ammoniacal Nitrogen

The difference between ammonia and ammoniacal nitrogen can be summarized in the following table:

In summary, ammonia is an inorganic compound with the chemical formula NH3, while ammoniacal nitrogen is a measure of the amount of ammonia in a sample, including various forms of ammonia and ammonium.