Ammonia is a highly alkaline gaseous pollutant with the chemical formula NH₃. It has no colour, has a sharp pungent odour (smell of urine) and bitter taste.
It is considered non-flammable, unless combined with Chlorine (Cl) which produces Hydrogen Chloride (HCl) or if in abundance, can form Nitrogen Trichloride (NCl₃) which is highly explosive. It is also considered explosive if certain concentrations are mixed with air.
Ammonia is produced mainly through agriculture as a result of manure, slurry and fertilisers, as well as other high concentrations of animal waste. Also but less significantly ammonia is produced as a by-product of waste treatment/ decomposition and diffuse sources including cleaning products and petrol vehicles fitted with catalytic converters.
Ammonia exposure can cause irritation to airways and eyes and potential negative impacts to the cardiovascular system at high concentrations. It is also a secondary source of particulate matter when reacted with other chemicals such as Sulphur Dioxide (SO₂) or Nitrogen Oxides (NOₓ) which can be linked to separate respiratory health impacts including lung and cardiovascular damage..
Ammonia also contributes to eutrophication (gradual harmful enrichment with minerals and nutrients) of waters through land run-off, soil acidification and overall ecosystem disruption.
As the majority of ammonia emissions are from agriculture, control measures used to reduce emissions are often the adaptation of farming practices to reduce losses to the atmosphere. Such examples are the use of plastic covers for slurry pits or similar storage management systems and also the adaptation of the method that fertilisers, and slurries are deposited to land. Deposition using trailing hoses, shoes or injection into farmland, can reduce the amount of ammonia within the deposited mixtures being lost to the air.
For non-agricultural sources of Ammonia, treatment of exhaust gases using abatement systems such as wet scrubbers are often used. These involve the injection of an acidic solution into the waste gas which neutralises the ammonia to produce ammonium salts and water (which can be reused).
Alkali Environmental perform periodic measurements of Ammonia in ducted emissions from point sources to the standard reference method BS EN ISO 21877. The reported results carry UKAS and MCERTS accreditation where the method can be performed to the standard.
These measurements are taken using a manual sampling train whereby a single result is obtained for a gas sample taken from the duct.