Ammoniacal nitrogen (NH₃-N) is a measure for the amount of ammonia, a toxic pollutant often found in

landfill A landfill site, also known as a tip, dump, rubbish dump, garbage dump, or dumping ground, is a site for the disposal of waste materials. Landfill is the oldest and most common form of waste disposal, although the systematic burial of the waste ...

leachate A leachate is any liquid that, in the course of passing through matter, extracts soluble or suspended solids, or any other component of the material through which it has passed. Leachate is a widely used term in the environmental sciences wher ...

and in waste products, such as

sewage Sewage (or domestic sewage, domestic wastewater, municipal wastewater) is a type of wastewater that is produced by a community of people. It is typically transported through a sewer system. Sewage consists of wastewater discharged from residenc ...

, liquid manure and other liquid organic waste products. It can also be used as a measure of the health of water in natural bodies such as rivers or lakes, or in man made water reservoirs. The term is used widely in waste treatment and water purification systems. Ammonia can directly poison humans and upset the equilibrium of water systems. The values of ammoniacal nitrogen in water or waste liquids are measured in milligram per

liter The litre (international spelling) or liter (American English spelling) (SI symbols L and l, other symbol used: ℓ) is a metric unit of volume. It is equal to 1 cubic decimetre (dm3), 1000 cubic centimetres (cm3) or 0.001 cubic metre (m3). ...

and are used for specifying water treatment systems and facilities. The typical output of liquid manure from a dairy farm, after separation from the solids is 1600 mg NH₃-N /L. Sewage treatment plants, receiving lower values, typically remove 80% and more of input ammonia and reach NH₃-N values of 250 mg/L or less. The ammonium nitrogen value is also used in the context of properly designed landfill systems, where the leachate is being pumped to the surface and treated before it enters the ground water, testing the quality of the water exiting the treatment system. The term NH₃-N removal is also commonly used in scientific publications as a short way to depict Ammonia in water, and not the measure of its quantity.

Structure and Basic Chemical Properties

Ammonium and ammonia forms of nitrogen compounds

Ammonia and Ammonium

Ammonium The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary a ...

is an ionized form of ammonia.
The chemical structure for ammonium is NH.
The chemical structure for ammonia is NH₃. Ammonia is highly soluble in water. Ammonia reacts with water (H₂O) and forms the ionized form: :NH₃ + H₂O ↔ NH + OH⁻ The reaction is reversible. The hydroxide ion (OH⁻) plus NH forms NH₃ + H₂O. The percentage of ammonia increases with increasing alkalinity of dissolved ammonium in water. Ammonium ions are formed with increasing acidity of dissolved ammonia in water. Ammonia is toxic to fish and humans. The toxicity is decreased with lower alkalinity and increases with higher alkalinity as ammonium is converted to ammonia.

Ammonia and mineral forms of Nitrogen

There are 3 main forms of nitrogen: * Molecular nitrogen * Mineral nitrogen * Organic nitrogen

=Molecular nitrogen

= Molecular nitrogen is the gas form of nitrogen in the atmosphere. The chemical structure for nitrogen gas is N₂.

=Mineral nitrogen

= The mineral forms of nitrogen are: *

Nitrate Nitrate is a polyatomic ion A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ...

with the chemical structure of NO *

Nitrite The nitrite polyatomic ion, ion has the chemical formula . Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name ...

with the chemical structure of NO *

ions, with the chemical structure of NH

s ions are nitrified and are converted by

microorganisms A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

into

nitrate Nitrate is a polyatomic ion A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ...

. Fish and humans are more tolerant of nitrate nitrogen than they are of ammonium nitrogen. In well aerated water, most of the mineral nitrogen is in the form of nitrate. See

=Organic nitrogen

= Major organic forms of nitrogen include

proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

amino acids Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...

, DNA, and

RNA Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...

References

{{DEFAULTSORT:Ammoniacal Nitrogen Ecological data