Fate of Ammonia: Overview, Diagram, Sources and Fate

What Is Ammonia?

Another very important compound, composed of nitrogen and hydrogen combined in molecular form as NH₃, is ammonia. Its fate is important in assessments because it is part of the nitrogen cycle, acting in effect as the critical intermediate in transforming nitrogen into forms usable by plants and other organisms.

Moreover, the application of ammonia in agriculture as a fertilizer and its impact on environmental health—through eutrophication and atmospheric pollution—make studies on this molecule very essential. This paper will present a summary of the production of ammonia, its transformation in different ecosystems, and the environmental implications of its presence and movement.

Sources Of Ammonia

Ammonia is produced from the following sources:

Natural Sources

Decomposition of organic matter: This occurs in the natural decaying of plants and remains of animals that emit ammonia into the soil.

Animal waste: Excretes from domestic and wild animals excrete quite large amounts of ammonia to the environment.

Anthropogenic Sources

Agricultural activities: Application of nitrogen-based fertilizers and rearing animals leads to the emission of ammonia.

Industrial processes

The manufacturing processes of numerous chemicals, like fertilizers and plastics, emit ammonia. Wastewater from sewage and industrial waste results in the production of ammonia.

The Nitrogen Cycle And Ammonia

The nitrogen cycle is the process through which nitrogen is transformed from one of its chemical forms to another. This is a change that holds a significant value to the existence of life on this Earth.

Role Of Ammonia In The Nitrogen Cycle

An important intermediate in the nitrogen cycle is formed by the decay of organic matter. This is also the starting substance for several conversion processes

Conversion Processes Involving Ammonia

In nitrification, ammonia gets oxidized to nitrites and then to nitrates, that too by the nitrifying bacteria, hence making nitrogen available to plants in a usable form.

Ammonification is the conversion of organic nitrogen into ammonia, done by decomposers like bacteria and fungi. This replaces the amount of ammonia in the soil and hence continues the cycle of nitrogen.

Fate Of Ammonia In Different Environments

The effect on ammonia varies based on the type of environment:

Soil Environment

• All ammonia can potentially bind to soil particles therefore making the ammonium less available for uptake by plants but more stable in the soil

• Soil microorganisms convert through oxidation the ammonia into nitrites and nitrates- plant-absorbable forms.

• These nitrates turn over and get again reduced into nitrogen gas through denitrification and released into the ecosystem.

Aquatic Environment

• Ammonia is easily soluble in water; hence, its concentration and bioavailability will vary in aquatic systems.

• Ammonia can easily and readily be absorbed by aquatic plants and microorganisms.

• It can readily provide the much-needed nutrition that the said organisms can easily utilise.

• On the contrary, large doses of ammonia represent lethal doses to fish and other forms of aquatic life.

• Ammonia is reduced to nitrite and nitrate through microbial action the same as that in soil, and all these processes are of equal importance in the aquatic nitrogen cycle.

Atmospheric Environment

• The ammonia can be volatilised in the atmosphere, mainly from soil and water under high temperatures and alkaline conditions.

• In the atmosphere itself, ammonia can react with acids to form ammonium salts, which affect air quality and atmospheric chemistry.

• Through precipitation or any other kind of dry deposition, O-ammonia and other derivative products get re-deposited back to the earth's surface and finally find their way into the earth's soil and water systems to enter into the cycle of nitrogen again.

Fate of Ammonia NEET MCQs (With Answers & Explanations)

The key concepts to be covered under this topic for different exams are:

• Steps of the Nitrogen cycle

• Nitrogen metabolism in plants

Practice Questions for NEET

Q1. Which of the following bacteria is involved in conversion of NH3 into nitrates?

1. Azotobacter and Nitrosomonas

2. Nitrosomonas and Nitrobacter

3. Azotobacter and Achromobacter

4. Pseudomonas and Nitrobacter

Correct answer: 2) Nitrosomonas and Nitrobacter

Explanation:

Nitrate formation -

Prokaryotic microorganisms known as nitrogen-fixing bacteria can convert atmospheric nitrogen gas into "fixed nitrogen" molecules that plants may use, such as ammonia. Nitrite is oxidised to nitrate by Nitrobacter, Nitrocystis

- wherein

2NO₂⁻ + O₂ → 2NO₃⁻ + Energy

NH₃ → NO₂⁻ → NO₃⁻

Hence, the correct answer is option 2) Nitrosomonas and Nitrobacter.

Q2. Which of the following organisms does not fix nitrogen?

1. Azotobacter

2. Nostoc

3. Spirogyra

4. Anabaena

Correct answer: 3) Spirogyra

Explanation:

Spirogyra is a genus of green algae that is not capable of fixing atmospheric nitrogen. Other than some cyanobacteria, other algae, for example, have the necessary enzyme, known as nitrogenase and the nif gene for fixation of nitrogen, Spirogyra lacks such. This places it on the disadvantageous side when it comes to contribution to the provision of nitrogen to an aquatic ecosystem, meaning it gets most of its nitrogen from external sources instead of fixing atmospheric nitrogen.

Hence, the correct answer is option 3) Spirogyra.

Q3. Minerals involved in carbohydrate translocation, maintaining ribosome structure and activation of nitrogenase respectively are

1. Mn, B, Ca

2. Ca, Mg, Mo

3. B, Mn, Mo

4. Cu, mg, B

Correct answer: 3) B, Mn, Mo

Explanation:

Minerals involved in carbohydrate translocation, maintaining ribosome structure, and activation of nitrogenase respectively are boron, manganese, and molybdenum.

Hence, the correct answer is option 3) B, Mn, Mo.

Also Read:

• MCQs on Fate of Ammonia

• Fate of Ammonia

• Essential Mineral Elements