An exclusive project report on Acid Rain. This project report will help you to learn about: 1. Meaning of Acid Rain 2. Formation of Acid Rain 3. Causes of Acid Rain 4. Effects of Acid Rain 5. Impact of Acid Rain on Environment 6. Prevention of Acid Rain 7. Methods to Control Acid Rain.
Contents:
- Project Report on the Meaning of Acid Rain
- Project Report on the Formation of Acid Rain
- Project Report on the Causes of Acid Rain
- Project Report on the Effects of Acid Rain
- Project Report on the Impact of Acid Rain on Environment
- Project Report on the Prevention of Acid Rain
- Project Report on the Methods to Control Acid Rain
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Project Report # 1. Meaning of Acid Rain:
Increasing acidity in natural waters and soil is becoming a problem all over the world, particularly in North East America, North West Europe and India. Acid rain has become an invisible threat present in rivers, lakes and forests of UK, USSR, Canada and Germany.
Generally rain water gets acidic because CO2, SO2 and NO2 present in the atmosphere get dissolved in it forming carbonic acid (H2CO3), sulphuric acid (H2SO4) and nitric acid (HNO3) respectively. Due to presence of these acids the pH of the rain water lowered to a value of 2.4 and this type of raining of lower pH is called acid rain. A value of pH below 5.6 denotes acid rain.
The harmful rain was discovered by an English scientist, Robert Angus Smith who came up with the term Acid Rain’ in 1872, when he saw corrosion on the surfaces of buildings and plants because of rain.
Air pollution ultimately leads to acid rain as the harmful gases, which are mixed in the air, also get combined with the moisture in the air and form acidic clouds, which lead to acid rain. The main causes of acid rain are factories, vehicles, power stations and industries; which burn fuels and produce harmful gases, which have sulfur dioxide or nitrogen oxides.
Acid rain primarily means the deposition of acidic elements in the forms of precipitation, which can be snow, rain, dew or fog. Normally rain is acidic though weak as the pH.
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There are two types of acid deposition, one is wet and the other is dry. Wet deposition is the one, which involves acid rain or snow or dew whereas dry deposition is when the particles such as polluting gases, dust particles and gaseous elements are just absorbed by the surface of the Earth or the plant bodies.
They are not converted into acids until and unless they are in contact with water. In case of wet deposition the acids are removed from the atmospheric air and are deposited on the surface of the earth.
Project Report # 2. Formation of Acid Rain:
In its purest state, rain water is like distilled water. It does not have carbon dioxide dissolved in it. It is neutral, with a pH level of 7. As rain water falls through the atmosphere, particles suspended in the air are dissolved in it.
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These substances are generally dust, pollen grains and carbon dioxide (CO2), sulphur dioxide (SO2) and nitrogen dioxide (NO2). Emissions of volcanoes and lightning tend to decrease the pH level of acid rain, making it even more acidic. CO2 combines with water to form carbonic acid (H2CO3),
H2O (1) + CO2 (g) = H2CO3 (aq)
Carbonic acid ionizes in water to form low concentrations of carbonate and hydronium ions.
2H2O (1) + H2CO3 (aq) = CO2-3 (aq) + 2H3O+ (aq)
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Carbonic acid is a weak acid. It brings down the pH of the rain water 6.5-5.2. With pH levels ranging between 6.0—5.2, rain water is acidic, but to still not dangerous. This is a reversible reaction.
The problem occurs when rain water combines with gaseous oxides of sulfur, nitrogen and phosphoric and hydrochloric acid mists. The latter two and sulfur are released into the atmosphere from automobile exhausts, industries and electric power plants.
Nitrogen forms a major part of atmospheric composition. These chemicals bring down the acid rain pH level to 5.6-3.5. Sometimes, the pH level can even become as low as 2. This phenomenon of acidic rain water precipitation is called acid rain.
Sulphuric acid and nitric acid are the main acids present in acid rain. Sulfuric acid is formed as follows:
i. Sulfur released into the atmosphere combines with atmospheric oxygen to form sulfur dioxide (SO2).
ii. Sulfur dioxide reacts with atmospheric water to form sulfurous acid.
SO2 (g) + H2O (1) = H2SO3 (aq)
iii. Sulfurous acid is also present in acid rain.
iv. Sulfur dioxide gradually oxidizes to form sulfur trioxide. (SO3)
2SO2 (g) + O2 (g) = 2SO3 (g)
v. Sulfur trioxide reacts with water to form sulfuric acid (H2SO4)
SO3 (g) + H2O (1) = H2SO4 (aq)
Formation of nitric acid starts with high temperature combustion processes. Most of the nitric oxide forms by burning of organic compounds of nitrogen. Nitric oxide is also released as a result of microbial nitrification in the soil. These nitric oxide reacts in a different way in day and evening time.
In day time, oxidation of nitric acid occurs by O2, O3 and ROO and from nitric acid as final product.
In evening time the mechanism is different from day time. The first step is oxidation of nitrite radical to nitrate radical but the final result is in formation to nitric acid.
All these acids collectively form acid rain.
Project Report # 3. Causes of Acid Rain:
Acid rain is a form of pollution that can cause of lot of damage to natural ecosystems, to man-made objects, as well can harm to human health.
Human activity is the main cause of acid rain. Burning of fossil fuels is the primary source of these gases. With increase in industrialization and number of vehicles running on the roads, fumes that contain these gases are being added to the atmosphere at such a rate that the excess of these gases can’t be neutralized by natural processes.
For example, combustion of fossil fuel in vehicles and industries like iron and steel, processing of crude oil and utility factories contribute to more than 70% of the sulfur dioxide that is added to the atmosphere.
Almost 75% of oxides of nitrogen are released by similar processes. However, natural phenomena like eruption of volcanoes, lightning, forest fires, rotting vegetables and action of bacteria on the soil also release these gases. However, their contribution amounts to less than 10% of the total amount.
Rapid industrialization is the main cause of increase in the incidence of acid rain and precipitation with low pH value is common in industrialized nations. However, an amusing acid rain fact is, that it need not occur at the same place from where the gases that form acid rain, are released.
Sulphur dioxide and oxides of nitrogen are very light and they can be carried far, away from the industries that actually spewed them. Hence, acid rain can also be experienced in places that are not heavily industrialized.
Acid rain, more accurately acid precipitation, is the term used for describing rainfall with a pH level lower than 5.6. This type of pollution is a matter of great debate currently due to the potential of its causing environmental damages all across the world. For the last decade acid rain has caused destruction to hundreds of lakes and streams in many parts of the world, including the US, Canada, and Europe.
The oxides of nitrogen, (Nox) and sulfur dioxide, (SO2) are the two main sources of acid rain. Sulfur dioxide, which is a colourless gas, is given off as a byproduct when fossil fuels that contain sulfur are burned. This gas is produced due to various industrial processes, like the processing of crude oil, utility factories, and iron and steel factories.
Natural means and disaster can also result in sulphur dioxide being released into the atmosphere, such as rotting vegetation, plankton, sea spray, and volcanoes, all of which emit about 10% sulphur dioxide. On the whole, industrial combustion is responsible for 69.4% sulphur dioxide emissions into the atmosphere, and vehicular transportation is responsible for about 3.7%.
Nitrogen oxide is the other chemical that acid rain is made up of. Any nitrogen compound that contains oxygen atoms of any amount is known as oxides of nitrogen. For example, nitrogen dioxide and nitrogen monoxide are oxides of nitrogen.
These gases are produced in firing processes which involve extremely high temperatures, e.g., utility plants and automobiles, as well as in chemical industries, such as in the production of fertilizers. Five percent of nitrogen oxide is emitted by natural processes like lighting, volcanic eruptions, forests fires, and action of bacteria in the soil. Industrial processes emit 32% and vehicular transportation is responsible for 43%.
Project Report # 4. Effects of Acid Rain:
The effects of acid rain are as follows:
i. Effects of Acid Rain on Plants:
The acid rain affects the crops as well as the vegetation. The effect of acid rain on plants is grave. It not only damages the root, but also stops its growth and brings an end to the life of a plant. The nutritive value of the soil is reduced to a great extent as an effect of acid rain. Acid rain effects can be seen on the useful micro-organisms which convert the decayed organic matter into essential nutrients for the soil.
The consequence is that the micro-organisms are killed resulting in reducing the availability of nutrients for the soil and plants. Also, the waxy layer of the leaves is damaged which make the plant more and more susceptible to diseases. On the whole, acid rain effects on plants make it difficult to survive in the extreme climatic conditions like storm, drought and heavy rainfall.
It even affects the productivity and the process germination in the plants. The acidity of the rain has also led to soil erosion by dissolving the forests and other vegetation. It takes away the essential nutrients of the soil and releases aluminum, which disables trees from sucking water from the soil.
The direct impact of the acid rain can be seen in the production of carrot, radish, broccoli and beet roots. The yield has reduced to a great extent because of the acid rain which damages the protective layer of the leaves and interrupts in the evaporation process which does not allow the plant to breathe and survive. This stops the process of conversion of nutrients into energy for the plants and thus, the yield is affected.
Soil contains many harmful minerals such as mercury and aluminium. These elements can’t be absorbed by plants and trees and are thus harmless. Upon contact with acid rain, these chemicals undergo chemical reactions with the acids.
As a result, compounds of aluminium, lead and mercury are formed. Plants and trees can easily absorb these compounds. Such elements, which are extremely harmful to living forms, ultimately affect the entire food chain. These chemicals not only harm to flora, but also the animals that feed on them.
ii. Effects of Acid Rain on Aquatic Life:
Apart from plants, acid rain also affects aquatic organisms adversely. A high amount of sulfuric acid interferes with the ability of fish to take in nutrients, salt, and oxygen. As far as freshwater fish is concerned, in order for them to stay alive they need to have the ability of maintaining a balance between the minerals and salts in their tissues.
The molecules of acid result in mucus forming in their gills, which prevents them from absorbing oxygen in adequate amounts. Plus, the acidity, which reduces the pH level, causes the imbalance of salt in the tissues of fish.
Moreover, this change in the pH level also impairs the some of the fish’s ability to maintain their calcium levels. This impairs reproduction the ability of the fish, because the eggs become too weak or brittle. Lack of calcium also causes deformed bones and weakened spines.
Acid rain has the ability to leach harmful heavy metals like aluminium and mercury from the soil. They get drained to the water body where aquatic life in hampered. Acid rain effects on streams and lakes are concerned with the health of water species.
Not only a large number of species are killed due to deposition of harmful chemicals inside their body but it also affects the health of human beings on consumption of different varieties of fish. These toxic chemicals also damage hatchings and their reproduction process. Decrease in number of species as a result of sudden deposition of acid is known as acid shock.
iii. Effects of Acid Rain on Humans:
Most of all, acid rain affects human health adversely. It has the ability of harming us via the atmosphere as well as the soil where the food we eat is grown. Acid rain results in toxic metals breaking from the chemical compounds that occur naturally. Though toxic metals may be dangerous, but as long as they exist in combination with other elements, they are not harmful.
Once acid rain causes these toxic metals to be released they can infiltrate into the drinking water, and the animals or crops that humans use as sources of food. This contaminated food can damage the nerves in children, or result in severe brain damage or even death. Scientists suspect that aluminium, one of the toxic metals affected by acid rain, is associated with Alzheimer’s disease.
Another adverse health effect of acid rain on humans is the respiratory problems it causes. The emissions of nitrogen oxide and sulphur dioxide cause respiratory problems like throat, nose and eye irration; headache; asthma; and dry coughs.
Acid rain is particularly harmful for those who have difficulty in breathing or suffer from asthma. In fact, even the lungs of healthy people can be damaged by the pollutants in acid air.
People if get exposed to acid rain will suffer from skin blisters, irritation and burns. Under high acidic condition, the skin gets burned. Scientists also say that the risk of getting skin cancer is highly increased due to acid rain. The health effect of acid rain also comes from other sources.
The harmful chemicals pass into human beings when they consume the plants and animals. Many rural dwellers suffer from health problems due to consumption of acidified drinking water directly from lakes and other water bodies.
iv. Effects on Buildings and Monuments:
Acid rain causes severe damage to buildings and marble statues. Acid rain reacts with the calcium carbonate (CaCO3) to form soluble calcium hydrogen carbonate or calcium bicarbonate,
Ca(HCO3)2 -CaCO3 + Acid rain = Ca(HCO3) (aq)
Calcium bicarbonate is a powdery substance, which is easily washed away with water or more specifically, rainwater. This is the way acid rain has partly eroded many world-famous monuments and buildings like the Taj Mahal in India, St. Paul’s Cathedral in London, and the Statue of Liberty in New York.
Acid rain can destroy stained glass windows in churches, bridges made of steel, and railway tracks. It corrodes metal, ruins the paint colours, weakens leather and forms a crust on glass surfaces.
Project Report # 5. Impact of Acid Rain on Environment:
Acid rain is now one of the most serious environmental problems in developed countries. Interest in the problem has increased significantly since the 1990s, especially since reports of extensive forest dieback in the then West Germany started to appear in 1975.
Concern quickly spread to Scandinavia, where large scale fish deaths were believed to be caused by acid rain, and where more recently concern has focused on forest changes and heavy metal mobilisation in stream, lakes and groundwater.
Acid rain is widely believed to result from the washout from the atmosphere of oxides of sulphur and nitrogen. Although these oxides exist naturally in environmental cycles and ultimately have natural sources, the main sources today are coal-fired power stations and smelter and motor vehicle exhausts.
These gaseous pollutants are light and immiscible and they can be carried hundreds—if not thousands—of kilometers by prevailing winds. The oxides may be mixed with other chemicals in the atmosphere to produce the poisonous and corrosive substances that either settle as dry fallout or are washed out by rain as acid deposition (Fig. 18.1).
Emissions and fall out were previously extremely localised, but since the introduction of ‘tall stacks’ policies in both Britain (since 1958) and the USA (since 1971) paradoxically to disperse particulate pollutants and hence reduce local damage, emissions are now lifted into the upper air currents and carried long distances downwind.
The tall stacks policies have thus turned a smoke problem into an acid rain problem. Neither winds nor acids respect political boundaries, so the pollutants are often carried across state and national frontiers.
Acid rain thus represents a hidden export from one country to another — the exporter gains through not having to install costly pollution control activity to limit emissions and the importer suffers from the adverse impacts on its environment. Thus acid rain is a critical problem for international relations and it rightly claims a high priority on the agenda of political debate—both within and between countries.
The acid rain debate now embraces many Western countries, including Canada, the United States, England, Scotland, Wales, Sweden, Norway, Denmark, Germany, the Netherlands, Austria, Switzerland and a growing number of eastern European countries including Russia, Poland and Czech Republic.
Those countries that are hardest hit by the problem (such as Canada and Scandinavian countries) are convinced that something must be done, without further delay, to reduce emissions and thus save their forests and lakes. With the belief that ‘charity begins at home’, over 21 governments resolved to cut their own emissions of SO2 by at least 30% (over 1980 levels) by 1993 and hope to persuade the main producers of the culprit oxides to join them in a truly international attack on the problem.
The most suitable solutions to the problems of acid rain require prevention rather than cure and there is broad agreement in both the political and scientific communities on the need to reduce emissions of sulphur and nitrogen oxide to the atmosphere. The technology now exists to make this possible.
However, clean-up programmes will be expensive and they might yield only qualified improvements. The problem of acid rain arises, strictly speaking, not so much from the rainfall itself as from its effects on the environment. Runoff affects surface water (such as rivers and lakes) and ground water, as well as soils and vegetation.
Consequently, changes in rainfall acidity can trigger-off a range of impacts on the chemistry and ecology of lakes and rivers, soil chemistry and processes, the health and productivity of plants and building materials and metallic structures.
Human health might also be affected via the intake of food and water contaminated with toxic heavy metals mobilised by fallout acid rain. The significance of such impacts is more than purely scientific—they affect the quality of life for humans, they threaten environmental stability and the sustainability of food and timber reserves and they pose real economic problems.
The most suitable solutions to the problems of acid rain require prevention rather than cure, and there is broad agreement in both the political and scientific communities on the need to reduce emissions of SO2 and NOx to the atmosphere.
Project Report # 6. Prevention of Acid Rain:
The numbers of possible solutions for acid rain that are available to us are aplenty. What matters more is to consciously enforce these solutions to stop acid rain and to do soon a wide scale. People all over the world must be made aware of the causes and effects of acid rain, and they should be thoroughly educated about it. Solutions to stop acid rain can only be successful through mutual cooperation.
Acid rain is very serious environmental threat faced by our planet today. Millions of people get affected by it on a daily basis. Acid rain occurs when high levels of sulphur dioxide and nitrogen dioxide enter in the atmosphere and start undergoing chemical transformation. These harmful gases are absorbed by water droplets in the clouds and they fall on the earth during rains.
They can damage the natural soil by increasing the acidity levels and also pollute rivers and lakes. Acid rain is actually a broad term which is used to describe different types of acid that fall from the atmosphere on earth. It’s mainly divided into wet and dry.
Parts of the world which experience wet weather have acid rain, acid snow and fog. Other parts, which experience dry weather for most of the year experience acid gas and acid dust.
Today people can see the effects of acid rain everywhere they go. Dead and weakened trees are a very common sign of acid rain, while in cities worn off or scarred buildings are also a result of acid rain. This problem is more prevalent in the northern hemisphere where there’s a huge growth in the number of industries.
Winds absorb more and more quantities of harmful gases produced by various kinds of industries. In addition to this, even natural sources like volcanoes, forest fires and lighting contribute to this man made pollution.
Project Report # 7. Methods to Control Acid Rain:
Some methods to control acid rain are given below:
i. Reduce the use of fossil fuels. This would decrease the emission of nitrogen and sulphur in the environment.
ii. One of the main causes of acid rain is a sudden drop in the pH levels of water and that happens because of absorption of harmful gases by the atmosphere. The best way to restore the pH balance of water is to limit the use of items, which run on gasoline.
iii. Drivers should ease up as soon as the yellow light rather than slamming on the brakes and they shouldn’t rush away as soon as the lights turn green. These small practices help reduce the wastage of gasoline and also help people save a lot of money on fuel.
iv. Always keep the vehicle tires inflated. Tires having proper pressure will provide users with a better fuel economy.
v. Use cycles or should walk to cover small distances.
vi. One of the most fundamental acid rain solutions is to utilize fuels that burn cleanlier or to burn coal more efficiently. This will greatly reduce the possibilities of acid rain developing in the atmosphere.
vii. As far as industrial power plants are concerned, the best solution is to attach devices known as ‘scrubbers’ in the chimneys of these plants. These scrubbers reduce the amount of sulphur produced in the smoke by 90-95%.
viii. For industrial power plants, there are many more acid rain solutions that must be enforced, as they are clearly the biggest contributors to the formation of acidified water droplets in the atmosphere. Industries must regularly inspect and clean all their emission equipment and chimneys and pipes.
ix. Fitting catalytic converters into the exhaust pipes of vehicles also reduces the amount of sulphur dioxide produced by the vehicles.
x. We can make a lot of changes on a personal level as well, in order to combat acid rain. We should restrict the use of our cars and vehicles and utilize other modes of transportation on a more frequent basis. We should also remember to turn off all our lights and electrical devices in case we are not using them.
All these acid rain solutions will be pointless unless people are informed and educated about the adverse-effects and harms of acid rain. A widespread and nationwide effort must be made to make people aware. Only after that is done will all the acid rain solutions actually make a difference.