ammonium

noun

am·​mo·​ni·​um ə-ˈmō-nē-əm 

: an ion NH₄⁺ derived from ammonia by combination with a hydrogen ion and known in compounds (such as salts) that resemble in properties the compounds of the alkali metals

Examples of ammonium in a Sentence

Recent Examples on the Web

It is constantly monitored by sensors and controlled by software that can adjust everything from temperature to pH. Finally, there is a filtration stage where any unprocessed solids are separated from the liquid, which contains minerals, ammonium, volatile fatty acids, and carbon dioxide. —Jacek Krywko, Ars Technica, 13 Sep. 2023

Turning waste into air and food The solution of minerals and ammonium flows to the third compartment, where two cultures of bacteria—Nitrosomonas europea and Nitrobacter winogradsky—await. —Jacek Krywko, Ars Technica, 13 Sep. 2023

For example, a 21-0-0 fertilizer (ammonium sulphate) contains 21 percent N and no P or K. —Rita Perwich, San Diego Union-Tribune, 3 Feb. 2024

Our new findings suggest that our microbes are likely playing a part in this recycling process by converting large nitrogen-containing molecules like proteins and nucleic acids into ammonium. —Jennifer Debruyn, The Conversation, 28 Sep. 2023

Nitrifying microbes in the soil can then convert the ammonium into nitrate. —Jennifer Debruyn, The Conversation, 28 Sep. 2023

In agricultural pollution, a key precursor of PM2.5, ammonium, may be more damaging to the brain, the researchers found. —Abdullahi Tsanni, STAT, 14 Aug. 2023

In addition to temperature and pH, the bandage's biosensor monitors levels of ammonium, glucose, lactate and uric acid; together these measurements provide information about inflammation, infection and stage of healing. —Simon Makin, Scientific American, 28 June 2023

This quaternary ammonium salt acts as a formaldehyde releaser. —Melissa Breyer, Treehugger, 8 Aug. 2023

Word History

Etymology

New Latin, from ammonia

First Known Use

1808, in the meaning defined above

Phrases Containing ammonium

• ammonium carbonate
• ammonium chloride
• ammonium cyanate
• ammonium hydroxide
• ammonium nitrate
• ammonium phosphate
• ammonium sulfate
• ferric ammonium citrate
• quaternary ammonium compound

Kids Definition

ammonium

noun

am·​mo·​ni·​um ə-ˈmō-nē-əm 

: an ion that comes from the combination of ammonia with a hydrogen ion

Medical Definition

ammonium

noun

am·​mo·​ni·​um ə-ˈmō-nē-əm 

: an ion NH₄⁺ derived from ammonia by combination with a hydrogen ion and known in organic compounds (as quaternary ammonium compounds) and in compounds (as salts) that resemble in properties the compounds of the alkali metals