Idk Flashcards
Four ways human may harm or alter the phosphorous cycle.
Phosphorous extraction from mines causes the phosphorous present in the soil to be removed from the cycle for human uses, and the remaining phosphorus going into rivers and streams as runoffs, where they are deposited.
The majority extracted phosphorous is used as fertilizers, where they return back to the soil, while depleting the underground phosphorous resources.
The remaining phosphorous is used for industrial purposes, such as in food industry(in sodas), and in detergents and cleansers. This is returned back to nature in the form of sewage and waste, or in the form of decayed organisms.
Excessive consumption of phosphorous by humans is toxic, while too much use of phosphorous fertilizers cause plants to die.
Eutrophication
Eutrophication, the gradual increase in the concentration of phosphorus, nitrogen, and other plant nutrients in an aging aquatic ecosystem such as a lake.
This causes excess of algae in the water bodies. Fishes and aquatic organisms start dying as the algae dies due to suffocation, as the algae blocks the sunlight.
(https://earthhow.com/wp-content/uploads/2017/07/Eutrophication-Process-1.png)
Nitrification
Nitrification is the biological oxidation of ammonia to nitrite followed by the oxidation of the nitrite to nitrate. The transformation of ammonia to nitrite is usually the rate limiting step of nitrification. Nitrification is an important step in the nitrogen cycle in soil.
(Nitrification is often done by nitrifying bacteria present in legume root nodes, lightning, etc. )
https://upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Nitrogen_Cycle.svg/1200px-Nitrogen_Cycle.svg.png
Denitrification
Denitrification is the decomposition of nitrates and nitrates, which releases nitrogen back into the atmosphere. It is done by denitrifying bacteria present in the soil.
Nitrification equations
The chemical equation for this process is NH3 + 1.5 O2 –> NO2- + H+ + H20. The second part of the nitrification process is called nitration. Nitration uses the enzyme nitrite oxidoreductase (NOR) to complete the nitrification process. The chemical equation for this reaction is NO2- + ½ O2 –> NO3.
Denitrification equations (Just for reference)
Denitrification generally proceeds through some combination of the following half reactions, with the enzyme catalyzing the reaction in parentheses:
NO3− + 2 H+ + 2 e−→ NO 2− + H2O (Nitrate reductase) NO 2− + 2 H+ + e− → NO + H2O (Nitrite reductase) 2 NO + 2 H+ + 2 e− → N 2O + H2O (Nitric oxide reductase) N 2O + 2 H+ + 2 e− → N 2 + H2O (Nitrous oxide reductase) The complete process can be expressed as a net balanced redox reaction, where nitrate (NO3−) gets fully reduced to dinitrogen (N2):
2 NO3− + 10 e− + 12 H+ → N2 + 6 H2O
Leaching
Leaching is the loss or extraction of certain materials from a carrier into a liquid (usually, but not always a solvent).
Leaching in agriculture means may refer the loss of water-soluble nutrients, or the process of how nutrient uptake occurs in plants.
Weathering
The process by which rocks and minerals on the Earth’s surface are broken down or dissolved. These bits are further transported away by erosion.
Weathering can occur due to wind, water, acid (acid rain ), temperature, etc.
Reasons for lack of Nitrogen present in soil.
(It is required for nitrogen to be in the form of nitrates and nitrates for plants to be able to absorb these nutrients dissolved in water.)
Leaching: excessive water dissolves the nitrates/nitrites, which sometimes seeps much more deeper than accessible regions.
Denitrification
Volatilization: Nitrogen is lost in the form of Ammonia (NH3) gas, especially in fertilizers containing urea. This occurs when urea converting into ammonium(NH4) has the intermediate form of ammonia (NH3).
Erosion and Runoff.
Crop removal: Or the process in which the nutrients from the soil are removed through harvesting, rather than the normal process of decomposition and return of these nutrients into the soil again.
Measures to deal with lack of nitrogen in soil.
To deal with lack of absorbable nitrogen in the soil, the following steps can be taken:
i) Adding fertilizers with nitrogen rich compounds such as urea. This would help to deal with loss of nitrogen from the soil due to crop removal and human influences, although too much of fertilizer can harm the plants.
ii) Adding reasonable amounts of water to plants and not overwatering plants. Human activities that may cause high precipitation or increase the risk of floods should be prevented.
iii) Drainage can help prevent water logging or excessive flooding and can prevent the excessive leaching of nitrates and nitrites.
- When plants perform ________ they take carbon dioxide out of the atmosphere and release oxygen.
- When animals perform __________ they take oxygen out of the atmosphere and release carbon dioxide.
- Deforestation and the burning of fossil fuels ________ the amount of carbon dioxide in the atmosphere.
- Decomposition ________ carbon dioxide.
- Water _________ carbon dioxide.
When plants perform (photosynthesis) they take carbon dioxide out of the atmosphere and release oxygen.
When animals perform (cellular respiration) they take oxygen out of the atmosphere and release carbon dioxide.
Deforestation and the burning of fossil fuels (increases) the amount of carbon dioxide in the atmosphere.
Decomposition (releases) carbon dioxide.
Water (absorbs) carbon dioxide.
Environmental implication of using phosphorous fertilizers. (some points may be repeated in other cards)
Phosphorus extraction(mining) residues when mined for fertilizers and phosphorous fertilizers runoff in streams, rivers and water bodies due to erosion and precipitation.
When excessive phosphorous is dissolved in water, it causes eutrophication, which causes the death of underwater growth due to excess algae blocking oxygen, carbon dioxide and sunlight in water bodies. Even outside water bodies, phosphorous may cause excessive growth.
On one hand this excessive growth on land prevents soil erosion and loss of topsoil, thus retaining the soil’s fertility; while on the other hand excessive plant growth drains other nutrients from the soil reducing the fertility of the soil.
Equations for respiration and cellular respiration.
Cellular Respiration: C6H12O6 + 6O2+energy(sunlight) → 6CO2 + 6H2O.
Photosynthesis: 6CO2 + 6H2O → C6H12O6+ 6O + energy(ATP).
Half/incomplete nitrogen cycle or only natural part.
The first step of the stage starts when Nitrogen passes from plants to animals due to the consumption of plants and further steps in the food chain. The next step occurs when the nitrogen present in decaying plants and animals, and organic wastes is returned back to the soil in the form of ammonium compounds either directly or through reactions. These compounds are converted into nitrates and nitrites present in the soil, through the process of nitrification(not included but some of it lost in the form of gases of ammonia during the process). These nitrates and nitrites are either absorbed by plants through soil or released into the atmosphere through denitrification.
4 points on reducing the amount of SO2 present in the air.
i) Treating emissions: To reduce the SO2 concentration in the air, the sulphur dioxide can be reacted with limestone during industrial processes to get a number of products.
ii) As the main source of SO2 are emissions from industries, electricity production and vehicles, the fossil fuels can be either cleansed of sulphur by washing off in case of coal and treating the sulphur with alkaline compounds in case of crude oil.
iii) In cases where the use of methods to separate fossil fuels from sulphur are more costly, obtaining much purer forms of fossil fuels with lesser impurities may help.
iv) Various alternatives to fossil fuels such as solar energy, electricity powered vehicles, etc. can be used as well.
