Category: Acid Rain

Introduction

Acid rain is a very serious environmental problem that exists today because of high-energy consumption in the industrial world. Acid rain is snow, fog, or rain that has been polluted by acid in the atmosphere. Rain is naturally acidic because carbon dioxide, found normally in the earth’s atmosphere, reacts with water to form carbonic acid. While “pure” rain’s acidity is pH 5.6-5.7, actual pH readings vary from place to place depending upon the type and amount of other gases present in the air, such as sulfur oxide and nitrogen oxides.

Acid rain is observed when sulfur dioxide (SO ) and Nitrogen oxide (NO ) are released into the atmosphere and mix with moisture in the air. Industrial processes and the burning of fossil fuels such as coal-fired power generators and ore smelting are the main culprits for the release of sulfur dioxide. Nitrogen oxide comes into the atmosphere in harmful amounts by the combustion of fuels in vehicles, furnaces (residential and industrial), and boilers.

These are the main causes of acid rain. The formation of acid rain happens when acidic compounds, mainly SO and NO are released into the atmosphere. The wind then carries the acidic compounds, both wet and dry, across land and water, sometimes, hundreds of kilometers from where the acid was produced. (Mittelstaedt, 2000) With the help of sunlight, the gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds in the atmosphere. The result is acid rain that falls back onto the earth by rain or dry surface exposure.

Main body

Acid rain is a major problem in areas of high industrial productivity especially coal-generated power stations and high transportation problems. Places such as Germany, Japan, China, Parts of Russia, Eastern Europe, eastern sides of Canada, and North-east America. The effects of acid rain in an area are dependant on the type of bedrock that a continent has. The more alkaline bedrock is the more the continent can ‘buffer’ the acid rain i.e. in Canada, Ontario and Quebec has no natural protection to acid rain and gets a lot of damage from acid rain. Acid rain has a serious effect on the natural and physical aspects of the environment. (Webber, 2003).

The acidification of lakes and rivers has a huge effect on the ecosystem and biodiversity that is natural and beautiful around us. Acid rain is powerful enough to damage trees, change the conditions of animals, and even affect the reproduction of insects and small mammals. While acid rain is known to cause large amounts of damage to the natural environment its effects on buildings are often overlooked. (Mahoney, 2002).

In fact, acid rain is a major factor in the decay of buildings, structures, and paints especially heritage monuments. Acid rain has been blamed for visibility damage and cases of respiratory problems such as bronchitis and asthma. The effects of acid rain are extensive and are becoming a more serious issue in today’s society. Controlling the problem of acid rain is an issue that everyone has to work together on. Acid rain travels so everyone is affected. To fix the problem of acid rain we have to first understand the causes and effects of acid rain and make the public aware of the issues that come with acid rain.

Conclusion

Water acidification has the least to do with acid rain and the whole thing to do pertains to soil chemistry, land use, and geology. Streams, lakes, and other aquatic volumes get over 90 percent of their water, in no way from rain rather from the facade surfeit that is filtered initially through quite acidic plane soils and macrobiotic substance and then through bedrock, which is inclined to defuse that acidity.

In New England and the Catskill region overall, 15 percent of lakes show evidence of such traits. While on the other hand, eighty-three percent of the affected lakes have been found acidic due to acid deposition. As such, the other 17 percent are most likely acidic in terms of natural circumstances but have been developed more acidic because of acid deposition. (Webber, 2003)

An Acid Mine Drainage (AMD) is water that drains out from coal deposit mining areas and has a lower pH which has been occasioned by the presence of sulphuric acid. In other words, an Acid Mine Drainage is usually acidic although not all mine drainages are acidic. This acidity is due to the high concentration of sulphuric acid. Rainwater is the origin of the sulfur-rich water which usually finds its way through the rock fractures which have been left behind after coal mining has taken place (Wolkersdorfer, 2000). Throughout the history of coal mining, this type of drainage has been a challenge on Wheeling Creek water point which can be traced back about 1800 years ago.

The growth and development of industries that dealt with Wheeling greatly depended on the use of energy derived from coal. In fact, most developments could only e carried out with the help of coal energy which had been found to be very useful then. Up to date, West Virginia’s industrial development still relies heavily on coal-bearing in mind that the mining of coal in this region is still one of the most dominant industries. Besides, most of the energy demands for industries located at the Ohio River Valley still depend on the use of energy from coal (Benner, Blowes & Ptacek, 1997).

Before the advent of 1950s, there was very little consideration put in place as far as the mining of coal and environmental conservation was concerned. Mining of this mineral resource was rampant and was done on large scale. Recently, the impact of coal mining on rivers and streams has been brought under necessary checks and balances. For instance, new and better methods of mining coal which are also environmentally friendly have been devised (Pašava & Kříbek, 1995). Besides, there is a myriad of environmental regulation policies that have been enacted to control the impact of coal mining on environmental pollution. In addition, several methodologies on effluent treatment from coal mining sites are being used to control pollution associated with Acid Mine Drainage.

Nonetheless, West Virginia still faces major challenges today related to coal mining and Acid Mine Drainage. There are quite a number of deep mines which have been abandoned for some time which are equally a threat to the environment due to the continuous discharge of acidic effluents. The level of water quality in West Virginia is of poor quality due to these acidic effluents. Moreover, the ecosystem within the rivers has been disrupted significantly. This paper attempts to explore and give an incisive report on the origin of Acid Mine Drainage as well as an assessment of methods that can be employed to clean up the drainage.

Origins and development of AMD’s

Natural impacts which result from general mining activities are responsible for Acid Mine Drainage. This process occurs due to the exposure of compounds that contain sulfur in the process of excavating through hard rocks. Excavation of the ground is usually deep and reaches the bedrock and groundwater level where most of the sulfur deposits are located (Pašava & Kříbek, 1995). Once these sulfur-containing compounds are left open, they become susceptible to the attack by moisture and oxygen. These two natural agents of rock weathering initiate the chemical reaction whereby sulfur gradually dissolves in the available water and mixes with oxygen to form sulphuric acid which has relatively high concentration.

The mining of metal ores well below the level of underground water has been a possibility since the use of steam engines was introduced. These engines have facilitated the procedure of avoiding any contact between water, oxygen and sulfur-containing compounds (Benner, Blowes & Ptacek, 1997). Once the contract is avoided, the formation of hazardous sulphuric acid and its relative impact on the environment is equally kept at bay.

Nevertheless, even with the use of steam engines, surface and sub-surface water run-offs which find their way through the open seams of exposed metal ores have led to the origin and formation of Acid Mine Drainage because a similar chemical reaction is initiated when water, oxygen and exposed sulfur ores are combined.

Mining has undergone a myriad of stages. The advent of mining saw the possibility of extracting metal ores that were only over and above the level of groundwater. This was relatively safe and environmentally friendly because the formation of Acid Mine Drainage could be avoided at all costs. The developments made in the mining engineering however, transformed the way mineral ores were being extracted from the ground. For instance, horizontal shafts were constructed so that there could be a way out of the mining site especially in cases where the mineral deposits were far much below the surface of the ground (Pašava & Kříbek, 1995). Another important function of these horizontal shafts was to provide a channel through which groundwater could be drained to nearby streams or valleys so that the lower levels of the mine could be easily accessed. As the mining depths increased with time, it became necessary to use steam engines to pump water from the mining sites. As a result of this development, the groundwater level was artificially lowered especially within the surroundings of the mining site. The value of the minerals which were mined managed to offset the costs incurred in pumping huge volumes of water from the vicinity of the mines.

In spite of this mining procedure, there is still an environmental challenge associated with it. It is definite that the mines will begin to flood if pumping of the ground is terminated. If pumping is not resumed in due time, the groundwater level will resume its initial depth. In cases where the mines have been abandoned and there is no need to pump water from the site anymore, the rising groundwater level will eventually resume its initial natural level and it will also catch up with the level of the constructed horizontal shafts that originally served the function of draining water out of the mine to the river valleys and streams. The very groundwater will begin to drain again using the adits into river valleys. Sincerely speaking, this type of water which is being drained into river valleys is not safe or recommended quality bearing in mind that it has contaminated itself with residues at the mining site.

Due to this contamination, a biologically mediated oxidative reaction takes place (Pašava & Kříbek, 1995). This type of reaction specifically affects compounds that contain sulfur. The fact that the mining sites often remain moist-free does not mean that no oxidation reaction can take place. Usually, sulfate salts are produced by sulfur-containing compounds. Although the salts are in solidified form, they are often generated in plenty and in a form that they can be available for further chemical reactions. These sulfate salts also contain many of the metals which are mined alongside the ores. The flow of water into the mining sites initiates dissolution process of the sulfate-containing salts. It should be appreciated that this dissolved mixture also contains metal elements from the ores and it is acidic in nature. It is also composed of the discharge from Acid Mine Drainage. The available sulfur salts are oxidized by the action of chemolithotrophic bacteria. As a result, the continuous discharge of Acid Mine Drainage from the mines is maintained for a considerably long period of time after the original flush.

Environmental Threats

Acid Mine Drainage is a real environmental threat especially in consideration of the fact most living organisms flourish well at a pH of around 7. Acidic or basic conditions favor only a minuscule fraction of life. This drainage is highly acidic and leads to the acidification of local watersheds. This may further hamper, disrupt or eliminate the river ecology. Fish and other vertebrates are even prominently affected by Acid Mine Drainage more than other animal and plant species (Benner, Blowes Ptacek, 1997).

Another accompanying problem is the metal parts which are part and parcel of the Acid Mine Drainage. Most mining sites that extract coal may not escape the possibility of discharging iron components in the Acid Mine Drainage. The poisonous nature of iron compounds makes its discharge into watercourses a big threat to both plants and animals. Both ferrous and ferric forms of iron are naturally toxic and high intake levels of the same cannot be tolerated by most living organisms (McElfish & Beier, 1990).

As Acid Mine Drainage is produced, it is usually in ferrous form. This form of iron is highly soluble in water and is not found in form of precipitates but as a soluble product. However, the presence of oxygen and of course moisture oxidizes the ferrous (Fe2+ ions) to ferric (Fe3+ ions) iron. The ferrous iron is red-brown in color and is in form precipitates because it is not soluble. The iron (III) ion is a solid with a high density. If this form of iron is concentrated in water even in small volumes, large precipitate amounts will still be generated. These precipitates have the ability to create a cover on land and stream surfaces especially at the point where the content is being drained. Consequently, the environment is smothered by this iron coating prohibiting the natural flow of water, air and other nutrients. As a result, it hinders life from the process of growth and development. One specific effect on fish is that their gills are coated. It is this coating effect that causes fatalities of fish although the metal itself is not intrinsically toxic.

After the closure of the mines, water pumps are not switched off instantly. The groundwater level has to be maintained at a lower level because other mines in the vicinity which are still operating should still be protected from the groundwater interference. However, pumping of water from the mines is more likely to cease in totality as mining in other nearby sites comes to an end. Later on, the rising groundwater will fill up the empty mines and the same will be discharged in river beds and the immediate environment. It is only through thorough treatment of water from the mines that adverse effects to the environment will be avoided (Demchak, Morrow & Skousen, 2001).

The risk of Acid Mine Drainage will extend to salmonid rivers. Since the natural watercourses and the ecosystem will have been disturbed, habitation will no longer be suitable in these rivers and this will lead to either deaths or massive migration of different animal species from the affected habitat. Moreover, the angling community will be duly affected and some monetary engagements will be necessary to offer remedy to the situation.

Even after treating the discharge from mines which are rich in acids, the challenge will still persist. For example, the Acid Mine Drainage affecting the pH of the water will still have to be treated in some way so as to reduce the level of acidity in the flowing water. Alternatively, it will also require the discarding of sludges that are rich in metal ions. These sludges are usually left as residues after water has been treated.

The Acidity of Mine Drainage

Although most mine drainages are acidic, there are some which are not. The effluent from the mining sites may be almost neutral especially if the geology of the area being mined is well endowed with calcium compounds or lime. Waters which test neutral even after sweeping through the mines are also saline or brackish in nature (Pašava & Kříbek, 1995). Nevertheless, this does not insinuate that drainages which are not acidic are environmentally friendly and do not require to be treated. Although most environmental degradation problems are associated with acidity, it should be noted that alkaline conditions also have their own share of problems and they equally need to be treated.

On the same note, it is also imperative to note that the presence of iron (III) ions is still a major threat to the environment (McElfish & Beier, 1990). An environment that is neutral will favor the rapid precipitation of iron and consequently cause the coating effect on land, watercourses and gills of fish as explained earlier. The only merit of a neutral pH is that it allows easier and quicker treatment of the discharge owing to the fact that the precipitation of iron is not very necessary. Adding lime to the mixture to precipitate iron is not required because the discharge is not acidic at all.

Nonetheless, this does not eliminate the challenge and associated financial costs of discarding waste materials that are left after treatment of mine water. All the water samples containing iron compounds are supposed to be treated before they are allowed into the environment. Since treatment of the Acid Mine Drainage remains to be the hallmark of dealing with this waste from the mines, it is crucial to identify who is specifically responsible for treating Acid Mine Drainage in addition to the best methods which can be employed in cleaning up the mine drainage.

The problem caused by the pumping of water from mining sites was not foreseen immediately even as the use of steam engines was embraced in the mining process. Better still, less concern on environmental conservation and protection prevailed especially in 19th century. Mining operations still go on and may not stop in the near foreseeable future unless the mining sites are depleted of mineral resources. The responsibility of cleaning up the mines squarely remains on the shoulder of the major key players in the mining industry such as mining companies and government agencies in whose dockets mining falls (Demchak, Morrow & Skousen, 2001).

Cleaning up of Acid Mine Drainage

Events which lead to the formation of Acid Mine Drainages are more delicate to the environment compared to other forms of pollutants like oil spillages and nitrate accumulation or flow in the environment. The main reason for this is that pollution is caused by Acid Mine Drainages are mostly non-biodegradable and as such they cannot be broken down with the passage of time. Microorganisms whose habitats are water can utilize nitrates while oil pollutants in the environment will eventually break down into other compounds namely carbon dioxide and water. However, iron and other metal pollutants will persist in the environment. The only transition they can undergo is changing from one form to the other. For example, iron (II) ions will be oxidized in the presence of moisture and active part of air into iron (III) ions which as discussed earlier, is even more hazardous in the environment due its coating ability (Benner, Blowes & Ptacek, 1997).

The problem associated with Acid Mine Drainage is not strange; it has been there and experienced for a long period of time. All the same, the AMD incidences which have existed in the past have been successfully treated using varying technologies. Industry players, academicians and governments have broadly collaborated in seeking solutions to the environmental challenge caused by AMDs.

Although an assortment of treatment methods for Acid Mine Drainages exist, lack of consensus on the best technology to use in cleaning up AMD has led to the use of different treatment methods each year. A case study of the Wheal Jane Acid Mine Drainage in United Kingdom is a typical illustration that each AMD incidence might require a specific method for treatment. At one time, this mine happened to produce an assortment of metals besides coal which was considered to be relatively harmful to the environment. The drainage discharged high levels of cadmium and zinc metals (Pašava & Kříbek, 1995). The common iron was also spotted in the discharge. In fact, it was due to the characteristic orange color which could be seen from afar that alerted onlookers. The government had to swing swiftly into action to contain the situation. After the incident, the Wheel Jane site was adopted as a test site for Acid Mine Drainage in United Kingdom.

Treatment Alternatives

There are two main treatment methods that can be employed in an Acid Mine Drainage. These are active and passive treatment systems. Inactive treatment system, there is need to continually maintain the operations of the system. For example, the supply of calcium hydroxide needed to neutralize the discharge from AMD may be required on a regular basis to facilitate uninterrupted running of the treatment plant. Another maintenance exercise needed in an active treatment system is the elimination and transportation of waste products from the point of treatment.

On the other hand, passive treatment systems do not require any significant maintenance exercises either on-site or off-site (Demchak, Morrow & Skousen, 2001). The system is expected to contain itself. In the event that maintenance is required, then it is often as minimal as possible.

Precipitation of other metal materials by use of lime active waste treatment systems is the most commonly used technology of cleaning up Acid Mine Drainages. The method has been in application for several years. Treatment using calcium hydroxide or commonly known as lime is perceived to be simple and vigorous. Moreover, the long-term usage of this method has also made it possible for users to predict the likely drawbacks and successes of this system. However, there is a myriad of environmental challenges presented by this method. Firstly, there is a significant amount of water contained in the material generated after the AMD has been treated with lime. Besides, it is very rich in metal elements. The presence of metals in the waste products implies that some specialized waste disposal facilities will be required (Wolkersdorfer, 2000). Unfortunately, this basically multiplies the cost of treating Acid Mine Drainage and unless funds are set aside for the additional costs, the waste treatment process will not be complete.

Secondly, the high volume of water in the wastes generated increases the amount of space occupied by the waste as well as the mass or weight. Hence, additional financial costs will be incurred for transporting the excess water in the wastes as well as more charges to cater for fees incurred in landfills. These associated costs can otherwise be avoided.

Thirdly, the acquisition of lime used in the precipitation process has negative environmental impacts on the areas where crude limestone is mined. The environment is grossly degraded by both the quarrying and transportation processes of limestone (Demchak, Morrow & Skousen, 2001). Due to these constraints, it is highly questionable if this AMD clean-up method is sustainable for a long period of time bearing in mind that the challenge of mine drainage has continued to grow with time. Hence, it is common knowledge that there is need to develop alternatives to seal the loopholes in the use of this system especially in regard to the material usage, waste disposal or the generation of materials that can be used instead of being wholly dumped.

There are several advantages of using lime in the active treatment of Acid Mine Drainage. For instance, this technology has been tried, tested and approved for use and so its setbacks are well known (Bell & Donnelly, 2006). This makes it possible for stakeholders to decisively choose which method to employ. Besides, this method is most effective in treating mine discharges that are highly acidic due to the use of lime that tends to neutralize much of the acidic discharge. Moreover, fluctuations in temperature which might affect other types of technologies have no effect on this method. The treatment process can proceed normally regardless of the rise and fall in temperature. Besides, the dam which is used to settle water is relatively efficient and water that originates from this settling point can be redirected into other watercourses without any cause for alarm. The parameters used for operating the treatment plant can be adjusted accordingly so that both the quality and quantity of water are adjusted accordingly whenever there is need.

In spite of these advantages, there are quite a number of drawbacks which are associated with the use of this type of AMD treatment technology. For example, the cost of maintaining the equipment is rather high this being an active system that has to be maintained on a regular basis. Scaling of the system automatically increases the maintenance costs (McElfish & Beier, 1990).

Elimination of certain metals like manganese requires the use of a very high pH. This on the other hand may remobilize hydroxides of other metals such as aluminum. Moreover, the sludge which is obtained as waste product has chemically complicated and not stable and hence the disposal of the product in the long term may prove to be a challenge. Besides, the very sludges are rather costly both in terms of handling and disposal due to their low density.

Lack of economic value on the sludges is another problem encountered in the system in spite of the large amount of calcium hydroxide used in the process to facilitate total precipitation.

Lon exchange

This is yet another type of active treatment method. Indeed, the costs incurred in the pH modification method described above can be reversed if the value of the recovered metals can be put into consideration. Base metals such as zinc and copper can be of great use if they are fully recovered from the system. The technology behind ion exchange can be employed in extracting useful metals from the mine drains. This takes place before the Acid Mine Drainage is precipitated with lime. Through the ion exchange technology, the base metal is concentrated good enough that it can be sold off to other users in need such as smelting operators. The main challenge in the use of the ion exchange method is that materials for ion exchange are very expensive to manage economically (Wolkersdorfer, 2000). It has been found out that the costs involved in producing the metals are greater than the value of the metals themselves.

Biological Treatments

The treatment of Acid Mine Drainage using wetlands was earlier proposed as a passive methodology for cleaning up the acidic discharge into the environment. However, this method works best for acidic drainages from mines whose contamination levels are quite low. Although this method has been used to treat acidic discharges, it has not been approved universally as the best method for treating mine water. The sulfate which reduces bacterial activity on wetlands has been used by some companies. This wetland component has been used to biologically treat Acid Mine Drainages using an active system. For the bacteria to function well, it needs a substrate that is carbon-based (Pašava & Kříbek, 1995). This substrate facilitates the process of metabolism although it does not make use of oxygen as it is always the case; it however utilizes the available sulfate from wetlands. As it is well known, most biologically mediated systems require a lot of air sparging. This method does not need this requirement.

The use of biological systems in treating Acid Mine Drainage may sometimes not be the best especially when used on its own without supplementing with other methods. In order to improve the efficiency of the biological system, lime is added to the acidic mixture to remove all the acidic components of the mine water. The biogenic systems generate products that are unstable especially in environments that are toxic in nature. As a result, the disposal of products is an issue of concern and it is important to make some considerations before the end products from waste treatment are eventually disposed of. Adsorbents can also be used in treating Acid Mine Drainage using biological systems. These adsorbents are produced biologically and their purpose is to concentrate metals that have been discharged from the mine water.

Alternative Adsorption Treatment methods

Adsorbents that are non-biological in nature can also be used to treat Acidic Mine Drainage as an alternative treatment method (Pašava & Kříbek, 1995). This type of technology has been approved and proposed for use in treating acidic discharges from mining sites. The principle behind this technology is the use of particles whose density and size are known. These particles basically adsorb metals from the discharged mine water. Later in the treatment process, there are physical processes that are applied to separate the individual solid particles from the solution.

Electrochemical Treatment

Electrochemical properties of the metals in the water discharged from the mining site are very instrumental in applying electrical technology in cleaning up Acid Mine Drainages (McElfish & Beier,1990). This method of treating acidic discharges is gradually growing in terms of popularity and use. However, the use of electrochemistry of metals in treating mine water discharges that are acidic requires a continuous flow of electric energy in addition to a technical support for the purposes of maintaining the system.

Physical Process

The use of physical processes in removing individual metals from the Acid Mine Drainage has often been thought of as a better option since metals are eliminated from the acidic discharge in form of crystals compared to the use of lime which leaves behind precipitates or sludges (Wolkersdorfer, 2000).

Conclusion

In summing up this report, it is imperative to reiterate that Acid Mine Drainage refers to the acidic water discharge which originates from mining sites. Although this discharge is an environmental pollutant, not so much emphasis was laid on its management in the past due to unawareness of how much it could impact the environment. However, a recent development has witnessed the enactment of necessary regulations to countercheck the release of the discharge into the environment.

The invention of steam engines which were used to pump water from the mines accelerated the discharge of Acid Mine Drainages to watercourses. Initially, mining was basically carried on the near-surface hence there was no need to excavate deep underground. However, as time passed by, there was need to reach the inner levels of the ground where mineral deposits could be located. This led to the construction of horizontal trenches which could not only permit the extraction of minerals but also channel water out from the mining sites. In the event that pumping of water from the mines was terminated, the initial groundwater level could assume its original water level and eventually mix with the mine residues consisting of metals and sulfate deposits. This mixture could then be transported to the immediate environment and watercourses causing harm to live organisms.

In an attempt to clean up the Acid Mine Drainage, several methods have been employed. The most commonly used technology is the addition of lime (calcium hydroxide) in the acidic discharge from the mines so that precipitation can take place and the mixture neutralized, safe and ready to be released to the environment. This is an active system of treating AMDs and is relatively costly because the system has to be maintained at all times for operations to continue. There are financial costs incurred as a result of transporting sludges

On the other hand, passive methods such as the use of biologically mediated systems require very minimal or no maintenance at all. Biological treatment requires the use of certain bacteria. Other methods of treating AMDs include electrochemistry and physical technologies.

Acid rain – words which we often read in books and hear in news, is a phenomena towards which we contribute directly or indirectly. As the name suggests, is precipitation made extremely acidic by atmospheric pollutants which causes harm to the flora, fauna and infrastructure. Acid rain contains elevated levels of hydrogen ions produces as a result of interaction between sulfur dioxide or nitrogen oxides with water.

In order to find remedies to this problem, we must delve deep and identify the causes at the grass-root level. The causes of acid rain include both natural and man-made activities. Volcanic eruptions and rotting vegetation are some of the natural causes of acid precipitation. However, burning of fossil fuels for electricity generation, running of industries and automobiles feature massively in the man-made activities causing acid rain.

Prevention Steps to Prevent Acid Rain can be taken as following levels.

• Individual
• National
• Global levels

Individual Level Prevention Steps to Prevent Acid Rain

As individuals, we can contribute our share by conserving energy, seeking alternative mode of transport and alternative fuels. It’s time we take energy conservation advertisements seriously. Switching off electric appliances when not in use, giving natural cooling methods preference over air conditioning systems, adopting a more nature-friendly lifestyle may prove to be helpful. Instead of taking cars, buses, bikes, etc. we can switch over to green ways of transportation. Cycling or walking our way to workplace or places of local need, carpooling and opting for vehicles which produce reduced emission of atmospheric pollutants, can actually be indeed helpful. Apart from this, switching over to solar powered appliances, utilizing hydraulic energy wherever possible and putting to use other forms of energy (wind, nuclear, etc.) to maximum potency rather than relying on fossil fuel will help prevent this predicament.

National Level Prevention Steps to Prevent Acid Rain

On a national basis, the ruling bodies of various nations can pass laws and enforces them. For e.g., the Clean Air Act Amendment of 1990 enforced in the United States puts a cap on the sulfur dioxide emissions Steps to convert all auto-rickshaws and taxis to CNG-operated ones in metro cities has been taken up by the Government of India. The Eastern Canada Acid Rain Program 1985 is also a similar initiative undertaken by the Canadian Government to curb sulfur dioxide emissions and to prevent acid rain. More awareness programs, campaigns, utilization of media to spread this awareness must be done so as to direct people’s attention to this ever-increasing trouble should be done. As trees have been a major healer for almost all environmental issues, planting of trees campaign must be undertaken.

Global Level Prevention Steps to Prevent Acid Rain

On a global basis, the various conferences and summits organized by the UN, must enforce protocols to be binding for all the member nations to curb sulfur dioxide and nitrogen oxides emission.It is the best steps taken by UN to prevent acid rain.

Conclusion on Steps to Prevent Acid Rain

On a whole, the choice depends upon us whether we want to make our future safe and green or face perilous consequences of acid rain. The two primary sources of acid rain is sulfur dioxide and nitrogen oxide. Automobiles are the main source of nitrogen oxide emissions, and utility factories are the main source for sulfur dioxide emissions. These gases evaporate into the atmosphere and then oxidized in clouds to form nitric or nitrous acid and sulfuric acid. When these acids fall back to the earth they do not cause damage to just the environment but also to human health. Acid rain kills plant life and destroys life in lakes and ponds. The pollutants in acid rain causes problem in human respiratory systems. The pollutants attack humans indirectly through the foods they consumed. They effected human health directly when humans inhale the pollutants. Governments have passed laws to reduce emissions of sulfur dioxide and nitrogen oxide, but it is no use unless people start to work together in stopping the release of these pollutants. If the acid rain destroys our environment, eventually it will destroy us as well.

Authors Lauraine Chestnut and David Mills documented the benefits and cost assessment of the US acid rain reduction platform. Special attention was given to the parameters specified under the US Acid Rain Program, specifically Title IV of the 1990 Clean Air Act Amendments. To accomplish that goal, the proponents of the study compared estimates made in 1990 to estimates made a decade after. Furthermore, the need to measure the benefits of the program in the context of human health was given special attention. Chestnut and Mills utilized estimates provided by the U.S. Environmental Protection Agency to determine the health and environmental benefits of the said program.

About the geographical area, Chestnut and Mills focused the scope of the study to include only the power plant industry within the United States. Therefore, data reports from specific regions in the United States became part of the said study. This measurement process was guided by the use of the Integrated Planning model, which is a multiregional model of the country’s power plant industry (Chestnut and Mills 253). Nonetheless, the spotlight was on a 36 by a 36-kilometer grid that covers portions of the continental United States and southern portions of Canada (Chestnut and Mills 256).

The proponents of the study were focused on determining the emission rate of electric power plants in terms of sulfur dioxide and nitrogen oxide. Be that as it may, it is not possible to fully understand the health issue without stating that the emissions of the aforementioned chemicals were mere precursors. The critical part of the emission reduction program was to find out the end-result when these pollutants entered the atmosphere. It was revealed later on that the most disconcerting discovery was that sulfur dioxide and nitrogen oxide emissions were precursors to the emergence of particulate aerosols, a compound that is harmful to human health. Therefore, the health issue was to reduce emissions to reduce particulate aerosols.

Methods and Data

To understand the cost-efficiency of the acid rain program about the perceived health benefit, it was important to figure out the estimated total annualized cost of applying the legal mandate found in Title IV. Using a report submitted to the U.S. Congress containing cost estimates derived from different assumptions and modeling tools, they were able to derive the correct data.

About the measurement of human health benefits, the study relied on data supplied by the US EPA. The US EPA in turn utilized information taken from a published source that was using a quantification method to calculate the human health benefits in the context of particulate matter aerosol. Once the estimates had been tabulated the data was fed to a simulation program called the Regulatory Modeling System for Aerosols and Deposition or REMSAD.

The appropriate use of the REMSAD enabled the US EPA to determine the expected volume of particulate matter in the atmosphere in the year 2010. Once the data measuring the particulate matter became available, this information was utilized and combined with health effects made available to the U.S. EPA. As a result, the proponents of the study were able to determine the health benefits of emission reduction protocols.

The proponents of the study were also interested in determining the ancillary benefits with regards to the reduction in the emission of pollutants from electric power plants. As a result, they also wanted to find out the following outcomes: 1) effects on visibility, 2) effects on natural resources; and 3) effects of acid deposition on materials.

Results and Discussion

It was discovered that for every ton of emission reduced, the government spent at least $250. The U.S. EPA and other related agencies did not expect the low cost of reducing the emission of pollutants. The cost projections in the 1990s were much higher than the recent estimates supplied to the U.S. EPA. In other words, to achieve a significant level of reduction in emissions, the government had to spend $3 billion in 2010.

After calculating the cost of hospitalization, medical expenses related to symptoms and the reduction in productivity due to weak lungs, inflammation, and morphological changes, the proponent of the study reported a positive cost-benefit outcome of at least $100 billion. In other words, if the reduced emission resulted in the prevention of health problems, there is no need to spend a hundred billion dollars in medical expenses. The proponents of the study provided a detailed breakdown of the health benefits with regards to the following medical issues:

• adult mortality rates;
• infant mortality rates;
• non-fatal heart attacks;
• acute bronchitis;
• asthma exacerbations;
• respiratory symptoms,
• work loss (Chestnut and Mills 258).

The cost-benefit analysis was in favor of the reduction of the emission of pollutants. However, the article discussed ancillary benefits as well. It was made clear that the successful application of reduction protocols was beneficial to the nation’s natural resources as well. The said pollution control process also ensures the security and integrity of the food chain with regards to the threat of bioaccumulation of toxins.

Conclusions and Criticisms

There was a favorable cost-benefit assessment with the application of Title IV protocols into the proposed reduction of the emissions emanating from U.S. power plants. The positive impact of the assessment was clarified through numbers 3 and 100. It only required 3 billion dollars to achieve savings worth more than 100 billion dollars. As a result, it was easier to conclude that the implementation of the acid rain program exceeded expectations. Be that as it may, there were concerns regarding the liberal use of simulation models that supplied the estimates in cost as well as health benefits.

The proponents of the study pointed out that there are always uncertainties in the use of simulation models in generating this type of data. Nevertheless, it is imperative to refine the process. Thus, they proposed the utilization of more limiting assumptions. They also suggested the use of stringent standards in the interpretation of the literature that was used to create estimates. Nonetheless, it was acknowledged at the end that the significant difference in the expenses needed to reduce emissions versus the estimated health benefits was more than enough to acknowledge the favorable cost-benefit assessment of the said acid rain program.

Aside from inputs on how to improve the calculation of the cost and health benefits, the proponents of the study also made recommendations regarding the need to look into the ancillary benefits of the said pollution control program. Taking everything into consideration, it was clear to all parties that it is prudent to suggest further reductions in the power industry’s pollutants like sulfur dioxide and nitrogen oxide.

Introduction

Pollution entails the introduction of substances into the environment in quantities that can change environmental conditions and in turn, harm organisms. Acid rain and ozone pollution are a form of pollution, which entails the release of gaseous and dust particles in quantities that destroy the integrity of the atmosphere and affect organisms in their respective habitats and ecosystems.

Essentially, the atmosphere is an integral natural resource of the earth because it contains and maintains gases in appropriate proportions, which are essential for the survival of organisms in nature. In this case, the occurrence of acid rain and ozone pollution is due to the emission of gases in huge quantities, which have the capacity to pollute the air. Singh and Agrawal state that human activities such as the burning of fossil fuels and natural causes such as volcanic eruptions release nitrogen oxides, sulfur dioxides, and ozone, which are precursors of acid rain (15).

These oxides combine with atmospheric water and form acid rain. Aggarwal et al. state that the interaction of nitrogen oxides and volatile organic compounds contributes to the formation of terrestrial ozone, which is a pollutant responsible for global warming (1991). In this view, to enhance understanding of air pollution, the research paper examines the nature of acid rain and ozone pollution and subsequently discusses its causes and effects.

The Nature of Acid Rain and Ozone Pollution

Acid rain is a form of pollution characterized by the presence of nitric acid and sulfuric acid in the rain, snow, hailstones, dew, and fog. The presence of nitrogen oxides (NOx) and sulfur dioxide (SO2) in the atmosphere leads to the formation of acid rain. According to National Atmospheric Deposition Program, carbon dioxide, oxygen, sunlight, ozone, and water catalyze the conversion of nitrogen oxides and sulfur dioxide into nitric acid and sulfuric acid, respectively (par. 2).

These acids then accumulate in the atmosphere and fall to the earth’s surface as rain, snow, dew, fog, and hailstones. The amount of nitric acid and sulfuric acid is proportional to the number of nitrogen oxides and sulfur dioxide that are present in the atmosphere (Singh and Agrawal 15). Hence, acid rain occurs when there are high proportions of nitrogen oxides and sulfur dioxide in the atmosphere.

Ozone pollution is a form of air pollution, which occurs when the amount of ozone (O3) increases in the atmosphere. Although ozone that is present in the stratospheric layer is important because it protects humans and organisms against harmful ultra-violet radiation, its presence in the tropospheric layer is harmful. Aggarwal et al. argue that the presence of ozone in the tropospheric layer constitutes pollution because it acts as particulate matter that scatters sunlight, promotes absorption of ultra-violet radiation, and causes global warming (1990). Hence, terrestrial ozone is a very harmful pollutant to humanity and organisms.

Causes of Acid Rain and Ozone Pollution

Human activities and natural processes are the cause of acid rain. The human activities that emit nitrogen oxides and sulfur dioxide are exhaust fumes from motor vehicles, industrial emissions from smelters and fossil fuels, and power stations that use fossil fuels (Singh and Agrawal 15). Given that exhaust fumes from motor vehicles and industrial emissions are common in urban centers, the emissions of nitrogen oxides and sulfur dioxides are very high.

National Atmospheric Deposition Program states that urban centers with high population density, automobile traffic, and industrial activities experience high levels of nitrogen oxides and sulfur dioxide emissions (par. 9). Natural sources of nitrogen oxides and sulfur dioxide are lightenings, oceans, and volcanic eruptions (Singh and Agrawal 15). However, these natural sources do not contribute significantly to acid rain.

An increased amount of terrestrial ozone occurs due to human activities, which release nitrogen oxides and hydrocarbons into the atmosphere. According to Aggarwal et al., motor vehicles, industries, and power plants burn fossil fuels and emit nitrogen oxides and hydrocarbons, which interact in the presence of ultra-violet radiation and lead to the formation of ozone (1990). The number of ozone peaks late in the afternoon after the emitted gases have absorbed enough heat to catalyze the formation of ozone.

Effects of Acid Rain and Ozone Pollution

Acid rain and ozone pollution have harmful effects on organisms because they have scorching effects on the leaves of plants. Given that acids have scorching effects, they destroy the integrity of the leaves and interfere with their functions. National Atmospheric Deposition Program states that acid damages leave and make them susceptible to environmental stresses and diseases (p. 12).

Singh and Agrawal also indicate that ozone damages leave by causing desiccation and changing coloration (1992). The damaged leaves lose their physiological functions of photosynthesis and cause plants to experience retardation in their growth and development. The ability to regulate the loss of water is lost; hence, predisposing plants to physiological drought. Moreover, the scorching effects of acids destroy the protective membranes of plants and make them susceptible to diseases.

Since organisms in the environment live within a narrow range of pH, acid rain causes a significant drop in the normal pH. Singh and Agrawal explain that acid rain causes acidification of water bodies and results in massive deaths of aquatic organisms such as fishes, amphibians, planktons, and microorganisms (18).

A slight change in aquatic pH has deleterious effects on organisms because it affects their biochemical and physiological processes. A normal aquatic environment has a pH of 6.5 or more, but a few organisms can survive at a pH of 5; however, none can survive on a pH of less than 5 (National Atmospheric Deposition Program par. 15). Therefore, acid rain has the potential to kill all aquatic organisms if it occurs on a large scale.

Acid rain also has a considerable impact on agriculture because it affects the availability of nutrients in the soil. National Atmospheric Deposition Program reports that acid rain lowers agricultural production by reducing soil nutrients, changing the proportion of chemicals in the soil, and killing important microbes in the soil (par. 16). Acid rain reduces soil nutrients because it dissolves and leaches them away. Singh and Agrawal’s state explain that acid rain reduces the pH of the soil and causes the liberation of cations such as potassium, magnesium, and calcium, which are important in the growth and development of plants (18).

When leaching occurs, the proportion of nutrients in the soil reduces, while the proportion of toxic heavy metal increases. A decrease in pH harms microbes in the soil, hence, reducing the rate at which important microbial processes occur in the soil. Ozone is a greenhouse house gas, which has the capacity to cause global warming and affect the distribution of rainfall patterns in various places globally. Aggarwal et al. assert that the increased concentration of terrestrial ozone contributes to global warming because it has a greenhouse effect.

Acid rain has harmful effects on humanity because it dissolves heavy metals and causes respiratory diseases. National Atmospheric Deposition Program states that acid rain pollutes water by dissolving lead and copper, which are harmful metals, and inhalation of acidic fog causes respiratory illnesses such as asthma (par. 19). Exposure to lead and copper causes mental and systemic illnesses. The elderly are prone to respiratory diseases owing to their aging respiratory system.

Despite the fact that ozone in the stratosphere is protective against ultra-violet radiation from the sun, its presence in the troposphere is harmful to humanity and organisms. Ozone pollution has harmful effects on humanity because long-term exposure increases the occurrence of asthma, skin diseases, and lung cancer among individuals (“Green Facts: Air Pollution” par. 3). Aggarwal et al. argue that the combined effect of ozone and carbon monoxide causes acid rain and subsequently contributes to the damage of lung tissue (1990). In this view, acid rain and ozone pollution are responsible for the increasing cases of lung cancer and asthma.

Given that acid has corroding effects, acid rain corrodes human structures. National Atmospheric Deposition Program reports that buildings, statues, monuments, vehicles, metallic structures, and tombstones corrode faster in acid rain than in normal rain (par. 21). In this case, acid rain hastens deterioration of human structures, and thus, reduces their longevity.

Conclusion

Acid rain and ozone pollution are the dominant forms of air pollution because they emanate from human activities. Emissions of nitrogen oxides and sulfur dioxide do not only lead to the formation of acid rain but also act as catalysts in the formation of ozone.

The combined effect of acid rain and ozone leads to the destruction of terrestrial plants, death of aquatic organisms, reduced agricultural production, the emergence of human diseases such as lung cancer, asthma, and skin diseases, and deterioration of human structures. Therefore, acid rain and ozone pollution are public and environmental health issues that require effective mitigation measures.

Acid rain is defined as precipitation in any form that has acidic properties, such as nitric and sulfuric acid which is formed in the atmosphere and falls to the ground. The pH scale is used the measure acidity and alkalinity in solutions. The lower the substance’s pH value is (less than 7), the more acidic the substance is. If the substance has a higher pH value (greater than 7) then the more alkaline it is. Normal rain has a pH value of 5.6, acid rain refers to solutions with a pH below 5.6 because carbon dioxide dissolves into the rain forming a weak carbonic acid. Throughout this experiment, the acids will have a pH of 2. This is due to the reason that building material in the real world is exposed to acid rain constantly, through many years. However, with this experiment, 3 weeks is the time frame, therefore, to simulate years of exposure, the pH of the acid was lowered.

Acid deposition is another term for acid rain, but acid deposition is a broader term than acid rain as it includes all the ways acidic components leave the atmosphere and return to the ground. Furthermore, there are two types of acid deposition wet deposition and dry deposition. Wet acid deposition occurs when sulfuric and nitric acids formed in the atmosphere fall to the ground mixed with rain, snow, sleet, hail, fog, mist, dew and other precipitates. Acid particles can deposit from the atmosphere without moisture in the form of dry deposition. This form of deposition includes dust and smoke, which later dissolves in water forming acids.

Furthermore, Acid rain can be formed from man-made or natural resources, in which sulfur dioxide or nitrogen oxides are emitted into the atmosphere where they react with water, oxygen and other chemicals to form sulfuric and nitric acid. The acids then mix with water before falling to the ground. The main acids that are apart of acid rain are nitric and sulfuric acid. The small portion of these acids is produced from natural sources, as nitrogen oxides can be formed when there is an extreme heating of air during a storm in which lightning is produced. Additionally, sulfur dioxide can be emitted into the atmosphere by erupting volcanoes and rotting vegetation. Although a portion of acid rain originates from natural resources, much of the acid rain and public attention originates from man-made sources. Sulfur dioxide is produced from the burning of fossil fuels, mainly coal and oil used in power plants Furthermore, the act of burning of fossil fuels to generate electricity generates 50% percent of total sulfur dioxide emission. The reaction of sulfur dioxide to form sulfurous acid is listed below: Furthermore, sulfur dioxide can be oxidized to form sulfur trioxide, which then dissolves in water in the atmosphere to form sulfuric acid as presented below. Combustion engines are the main sources of nitrogen monoxide The burning of fuel releases heat energy, which helps combine nitrogen and oxygen.

This reaction also helps combine to form Nitrogen dioxide and the oxidation of nitrogen monoxide also forms nitrogen dioxide. Nitrogen dioxide dissolves in water in the atmosphere to form a mixture of nitrous acid and nitric acid. Moreover, acid rain is not limited to the area where the sources emitted the chemicals, as winds can blow sulfur dioxide and nitrogen oxide over long distances before being deposited, therefore, acid rain can affect many areas. Methanoic acid and Acetic acid will also be used in this experiment, as these acids are the dominant carboxylic acid in the troposphere. Both of these acids are major sources of atmospheric acidity and both contribute to more than 60% of the acidity in precipitation in remote areas and 30% in more polluted regions. These acids originate from the oxidation of volatile organic compounds and are emitted through a variety of ways. Furthermore, hydrochloric acid will be used as volcanic activity can also produce this acid. Hydrogen chloride can be emitted when coal is burned and when waste is burned, this occurs because coal and waste foods contain common salt (sodium chloride), which then reacts with hydrogen to give hydrogen chloride. Moreover, this Hydrogen chloride gas reacts with water in the air to form clouds of hydrochloric acid.

Acid rain has been linked to many detrimental effects on the environment and in human health. At higher elevation trees tend to be surrounded by acidic clouds and mists. Therefore, acidic deposition can damage the leaves of trees and it could remove minerals and nutrient from the soil, so the trees become susceptible to disease. For plants, acid rain can cause widespread damage as it has been known that acid rain can be the direct cause of slower growth, injury or death of plants. Dry deposition can negatively affect plants by blocking the pores for gas exchange. The negative impacts of acid rain can also be seen in aquatic environments, such as lakes, streams, and rivers where it can damage the wildlife there. When acid rain flows through the soil, the rain can leach aluminum particles into the river. The aluminum ions interfere with the fish’s gills and reduce their ability to take in oxygen, therefore fish communities dwindle due to high mortality and failed reproduction. A health lake has a pH of 6.5 or higher, and only a few fish can live at a pH below 5, when the pH reaches 4, the body of water is considered dead. Acid deposition also has a significant impact on building materials. Since marble and limestone are both forms of calcium carbonate, sulfuric acid can react with them, forming the calcium salt CaSO4. The reaction is shown below: Calcium sulfate has greater molar volume than calcium carbonate, therefore, when it is formed it causes stress for the material. These reactions cause the erosion of structures, as many buildings and statues are subject to the negative impact of acid rain. Furthermore, Acid rain also inflicts damage on metals, as it causes corrosion. Acid deposition reacts with metals such as iron to form salts. Therefore, ionic conductivity occurs which leads to an increase in the rate of electrochemical corrosion reactions such as rusting.

Because of these reactions, Acid rain causes significant damage to metallic structures such as buildings, bridges, and vehicles. The focus of this investigation will be on the impact of acid rain on metals, specifically tin. Tin is a highly workable metal, it is used as sheets in the construction of buildings and roofs, for storage containers, and for soldering or joining metal parts. Therefore, it is highly beneficial to test different acids and their impact on tin. Furthermore, tin is relatively unaffected by both water and oxygen at room temperature, it does not corrode easily. Tin is attacked only slowly by dilute acids such as hydrochloric acid and sulfuric acids.

This paper focuses on one of the main pollution related problems that affect the modern day world. The problem under study is acid rain. This form of rainfall is yet another of mankind’s caused problems since it results from production of nitrogen oxides, carbon dioxide and sulfur oxide gases in large amount due to activities such as deforestation and burning fossils to produce electricity. The implications of this form of rainfall on various ecosystems are discussed in this paper with suggestions being made on how to bring the problem to an end.

Acid rain is a form of rainfall which contains a high concentration of hydrogen ions and thus, it is more acidic than normal rainfall. Normally pure rain water is acidic due to the carbon dioxide in the atmosphere which is dissolved when the rain is falling (Luoma, 1984). Pure rainwater has a PH of around 5.6 but as it lowers due to various factors, it becomes more acidic and on reaching a PH of 4, it is referred to as acid rain. In general, any rainfall below a pH of 5.6 is acidic. The main cause of acid rain is the reaction of sulfur dioxide (SO2) with hydrogen peroxide in the clouds; a reaction which results in production of sulfuric acid which lowers the acidity of pure rainwater (Westone, 2012). Nonetheless, an array of other factors discussed in this paper contributes to this form of rainfall. This paper discusses acid rainfall by supporting the claims of the thesis that, acid rain results from both natural and man-made related activities and even though it can be neutralized, it has an array of negative impacts that greatly supersede its positive effects. The natural resources which humans use to produce electricity and other forms of energy are called energy resources. In many countries, the energy comes from burning fossil fuel such as natural gas and coal which were formed many years ago from dead animals and plants (Boyle, 2004). In the process of obtaining energy from these fossils, pollution emerges through the production of harmful gases as these substances burn (Luoma, 1984). Although sulfur dioxide, nitrogen oxides and carbon dioxide occur in the air naturally, burning the fossils leads to increased volumes of these gases in the atmosphere (Nixon, 1995). These gases can rise very high in the atmosphere and when they do so, they combine and react with oxygen and water leading to formation of acidic pollutants which contribute to acid rain.

Additionally, the acts of human beings cutting down trees increases the carbon dioxide concentration in the atmosphere which also contributes to a significant proportion of acid rain which falls on earth surface (Mohnen, 1988). High combustion in diesel motor vehicles is also a leading cause of nitrogen oxide production and thus can be termed as a contributing man-made factor of acid rain.

On reaching the earth, acid rain has numerous impacts but it is naturally neutralized by alkaline substances on earth. For instance, rocks and other minerals in the soil neutralize the effects of acidic rain since they are highly alkaline and their PH levels are above 7 (Boyle, 2004). However, the degree of neutralization depends on time exposure and the level of reactivity of the minerals and other basic elements in the soil. Therefore, the acidity of massive water bodies depends on this soil factors as well as the acidity of the rain. Lakes and seas mainly get their water sources from streams, rivers, underground water sources and rain water. Thus, rainfall with a PH of 5.0 for instance, can produce a lake or stream with similar acidity if the water flows through a granite surface which is smooth and flows directly to the massive water body. If such water flows on a soil or river base rich in limestone fragments, the acidity may be completely neutralized and have a PH of well above 7 on the PH scale (Luoma, 1984). In some areas, the buffering effect of the soil is poor and this results in a more acidic lake with a PH of less than 5 as is the case with the water bodies in northeastern United States (Pawlick, 1984).

Despite the fact that it can be neutralized, acid rain has major effects on various ecosystems. One of the highly affected ecosystems is aquatic life. As lakes and seas become more acidic due to acid rain, the living things such as fish and plants decrease rapidly. Some of the animals and plants in lakes and oceans are able to tolerate acidic levels, but others are acid sensitive and might die as the PH level constantly decreases (Ostmann, 1982). Many lakes affected by acidic rains have less or no fish, since at PH of 5 and lower their eggs do not hatch. Acidic rain deposition in soils mainly affects three important elements namely aluminum, calcium and magnesium (Ostmann, 1982). According to Greg Lawrence, a forest and a terrestrial system specialist, calcium in the soil is very important as it helps in wood formation in trees. If trees do not get enough amount of calcium, they are susceptible to stunted growth which leaves them to a risk of being crumbled down by insects and strong weather such as heavy rainfall (Mohnen, 1988). Studies carried out on spruce trees in the northeast America show that acidic rain has an adverse effect on plants and trees (Boyle, 2004). From 1910 to 1950 there were high levels of calcium in this tree which was well before industrialization took place leading to increased sulfur dioxide and nitrogen oxide gases associated with acid rain. Acid rain has also resulted in the deterioration of the forest floor in many natural forests. As the rain showers on these forests, the acidic rain drops fall on the leaves and dribs down onto the stems and into the soil (Ostmann, 1982). This reduces the buffering activity of the soil and many indigenous plants may not thrive well in the acidic soil resulting in extinction (Pawlick, 1984). Places such as the northern United States have low buffering activities of the soil such that their PH changes rapidly resulting in acidic soils.

Soils in the forest areas are highly sensitive to the acid rain which may adverse effects on plants growth. The buffering capacity (the ability of the soils to resist a change in PH) of the soils drop due to a lot of acidic rain lowers as more amounts of acid rain is deposited in them. Therefore, acidic rain causes an imbalance in the ecosystem in general (Mohnen, 1988). Ecology has proven that if one of the elements in the ecosystem is affected the other elements of the ecosystem are affected in one way or another. Thus, since the acid affects the trees and other plants, the predator-prey relationship is also affected since one of the elements of the food chain is not wholly involved (Pawlick 56). The entire ecosystem is highly interdependent and the organisms heavily rely on each other due to factors such as food webs where a species depend on other species for food and food chains (Ostmann, 1982). In addition, acid rain also affects the long range transport of the air pollutants and affects areas far from where the acidic rain actually spurts out from (Hordijk, 2010). A real life example is the transferred effect of acid rain in Canada, which actually originated from the United States and spread to Canada by wind flows (Hordjik, 2010). Another example is the case of the pollutants from china being transported by wind currents from China to India. The pollutants collect over the Indian Ocean and are pushed by the wind currents to central India whereby they are experienced as acid rain (Pawlick, 1984).

Acidic rain also impacts negatively on humans in terms of various health issues such as respiratory problems. Just as clean rain tastes and feels, acidic rain cannot be differentiated as much in comparison to the normal rain (Nixon, 1995). Nonetheless, the constituents of acidic rain such as sulfur dioxide and nitrogen oxides and other particulate matter affect and irritate human lungs as they inhale them (Westone, 2012). This mostly affects people with respiratory diseases such as asthma or those whose lungs have already been infected by respiratory diseases before (Mohnen, 1988). Acid rain also has an adverse effect on man-made materials and various natural features such as stones. The rain ‘’eats away’’ metals and almost everything exposed to it for quite a long time (Hordijk, 2010).

Even though human made features deteriorate with time, acidic rain speeds up the deterioration process. Acidic rain causes rust in metals and leads to deformation in marble statues by wearing them out. This is mainly caused by marble (calcium carbonate) being dissolved by the acids in the rain. Many of the buildings and statues in the world are made of calcium carbonate and limestone which are damaged by acid rain through chemical reactions. A typical example is the historical monument such as the Lincoln Memorial in Washington D.C which has been worn out due to the rain (Luoma, 1984). From chemistry, there is knowledge that once the pollutant deposits on the stone in the form of acidic rain, it can interact to create an alteration crust, which is usually calcium sulfate. The calcium sulfate is more water more soluble than the stone itself and with subsequent rains the alteration crusts are removed (Pawlick, 1984). Unlike other components of an ecosystem which can recover from the acid deposition, stone structures cannot be recovered.

As much as acidic rain has negative effect, it is important to acknowledge its significance. Acidic rain has been proved to have positive effects to crops through controlled experiments whereby crops such as corn and soybeans have been exposed to acidic rain and have shown positive results such as improved productivity (Boyle, 2004). The control test shows that there is no much negative effect on the growth of such plants even when grown under conditions of ten times the acidity. Research also shows that the nitrate component of the rain and to lesser effect the sulfate component of the rain are of major benefits to the plants due to their nutritional requirements (Luoma, 1984). This helps the farmers save on costs associated with plant growth such as the need for fertilizers needed to ensure maximum crop output. Nonetheless, in general, the harm causes by acid rain generally outdo the few benefits associated with this form of rainfall.

In conclusion, acidic rain negatively impacts trees, plants, lakes, human structures, streams and human health. Human beings have evolved to develop many systems that help them in their lives, but with less or no clue what consequences would follow these inventions. For instance, after research and extensive studies, scientists have come to find out that fossil fuel combustions are a major cause of pollution that leads to the formation of acid rain. The research and studies completed and those ongoing are an important step for future control of acidic rain globally. Many countries have taken the issue seriously and have used information from such research as evidence and channel to formulate laws which proof that change need to be made to control these changes. Various changes have been made in many countries in order to eradicate the problem of acid rain. Examples of newly adopted changes include the use of cleaner fuels, government enforced regulations on pollution, energy efficient and non-polluting products are among the changes (Hordijk, 2010). While there have been enormous improvements in the way the world produces energy, pollution is still rampant and in an extensive state such that it is difficult of the world to go back to a situation whereby there was no acid rain at all. Nonetheless, the world encompasses many ideas and brain power to develop renewable energy resources, but the money to develop these projects all seems to be tied up in the fossil fuels. With strict rule and more strategies to control the operations causing pollution, we will have a better globe and a future with no worry of acid rain.

Acid rain can also be termed acid precipitation which is described as rainfall whose level of pH is lower than 5.6 making it acidic. This form of rainfall results from the combination of Sulphite and Nitrogen oxides with the atmosphere resulting in the formation of Nitric and Sulphuric acids. (Weathers, K. C. and G. E. Likens p 10). The increasing level of pollution through acid rain all over the globe is a major concern that requires a quick and sustainable solution.

The formation of acid rain has two major sources that include nitrogen oxides as well as sulfur dioxide. Nitrogen oxides include any form of Nitrogen chemical compounds that contain atoms of oxygen gas like for example Nitrogen dioxide. Emissions of Nitrogen dioxide include; industrial processes that use extremely high degrees of temperature, industrial chemicals, for example, those from industries that manufacture fertilizers, and from processes that occur naturally for example the action of bacteria in the soil, volcanic activities, forest fires and lightening.

5% of the emissions of Nitrogen oxides are from natural processes, 43% from the transport sector while the other 32% is from industrial combustion. (Bailey, T. G. et al, p 13). Nitrogen dioxide does not only become poisonous when it combines with Sulphur dioxide but also by itself. The gas adversely affects the human respiratory organs and also damages the Ozone layer. (Likens, G. E., et al, p 47).

Sulfur dioxide abbreviated as SO2 is a colorless gas produced in the combustion of sulfur-containing fossil fuels, industrial manufacture of metals such as Steel, Zinc, Copper, and Iron, the processing of crude oil, and the occurrence of natural disasters such as volcanic eruptions. Research has shown that about 10% of the emissions of Sulphur dioxide are from volcanic eruptions. Sulfur dioxide in this case is the by-product of these processes. (Berresheim, H.; Wine, P.H. and Davies D.D, p 23).

pH is a symbolic indication of the extent of acidity or basicity or acidity of a solution about the level of hydrogen ions within that solution. The level of acidity or basicity is measured using a pH scale which indicates 7 if the solution measured is neutral for example water, less than 7 if the solution is acidic, and above 7 if the solution is basic. Living organisms can survive at 6.5-8 pH levels.

The activities of man are the major causes of acid rain. Industrial factories, for example, are to blame for the release of pollutants into the environment such as by the release of gases from the burning of fuels such as coal and other hydrocarbons fuel. The transport sector is another human activity that can result in acid rain mainly as a result of the Sulphur dioxide and Nitrogen oxide gases released as exhaust fumes from cars, buses and trucks. (Weathers, K. C. and G. E. Likens p 347).

The increasing level of acid rain has continued to harm the world causing serious implications to man, animals and even plants. Acid rain has had adverse effects on forests hence destroying the water catchment areas and sources. The slow growth and unhealthy state of forest trees have been attributed to acid rain that makes leaves turn brown and eventually wither and fall off. The poor state of these trees is due to the acidic water or rain that gets seeped into the soil causing the soil to weather and lose nutrients hence depriving the trees and other plants of the essential nutrients. The increased level of soil pH also accelerates the formation of highly toxic metallic elements such as Aluminium that hinder the uptake of nutrients by plants. (Likens, G. E., C. T. Driscoll and D. C. Buso, p 83)

An increased frequency in acid rain leads to a loss of the waxy coat that covers the surface exposing these leaves and the entire plant to diseases, insects, and harsh weather and even weakening the plant to the extent of death.

The damage of food plants by acid water can however be reduced by the use of fertilizers and lime that helps in replacing the nutrients. Limestone can for example be used to enhance the capability of the soil to withstand high levels of pH mainly in cultivated regions.

Acid rain also heavily affects both aquatic and land organisms. An increased level of acidity hinders the ability of aquatic organisms such as fish to take up various nutrients, oxygen and even salts. Fish living in freshwater lakes for example have to always maintain an equal mineral and salts balance in the tissues for them to keep alive. Increased acidic level in the water disrupts this balance leading to an extremely high number of fish deaths.

An increased number of acidic molecules leads to the formation of a mucus membrane in the gills which in turn hinders the absorption of adequate amounts of oxygen. (John McCormick p 231). A study by the United States EPA indicated that about seventy-six percent of the lakes which are acidic occurring only in the United States and fifty percent of the acidic streams are as a result of acid rain. (US EPA, p 40).

The pH change in the water bodies also affects the maintenance of an adequate level of Calcium in fish thus impairing reproduction in fish due to the weakening of the eggs. This leads to a high level of population decline of fish as there are very many deaths with very few young ones being hatched.

The effects of acid rain on man are serious and mainly impact negatively the air we breathe, the soil and the water. Sulfur dioxide and Nitrogen oxide emissions are major causes of respiratory complications that include asthma, lung damage, dry coughs, headaches, and eye, nose and throat irritations. Acid rain is known to hasten the rate of breathing difficulties and asthma attacks in asthma patients.

The release of metals that are highly toxic by acid rain has harmful effects on man though these effects can only occur if these metals combine with other available elements. The released metals can easily dissolve in crops, animals, and drinking water substances that act as man’s source of food.

The ingestion of these food substances can lead to the damage of nerves in young children, severely damage the brain and even cause death. An example of a disease caused by the ingestion of these substances is Alzheimer’s disease which is said to be a result of aluminum ingestion. The aerosols of Nitrates and Sulphates and other atmospheric particles are not only known to cause fatal diseases such as cancers but also cause reduced visibility which can be very dangerous especially for drivers on the road whose poor visibility can result in many road accidents. (W. N. Rom, p 102).

An indirect effect of acid rain on man is through the destruction of the various structures, materials, and equipment that have been created by man. The acidic rain can lead to the corrosion of stone and even ceramic structures, corrosion of metals and paints, textiles, limestone, sandstone and even marble. This occurs when a chemical reaction occurs between the sulphuric acid present in the water and the compounds of calcium in the stone leading to the formation of gypsum which easily flakes off.

The situation is mainly common in gravestones whose inscriptions have completely faded away. Acid rain also leads to iron oxidation, this explains the corrosion of many iron-constructed structures.

The increasing level of acid rain and its harmful effects on the environment and even on man necessitates serious action by all sectors. The government, public, and other private sectors should work together to eradicate acid rain. A few strategies have been put in place to deal with this problem. One such strategy is by a significant number of governments who have authorized those producers of energy to use scrubbers to trap pollutants before the waste gases are released into the open atmosphere such that no poisonous gas is released into the air. Another strategy has been the adoption of clean fuels.

Though these among other strategies have been put in place, a lot more has to be accomplished. Adequate education on the causes, impacts, and workable solutions to acid rain needs to be done. This will not only instill knowledge but also inform each sector on the various roles they can each play to completely fight the occurrence of acid rain. The solution lies with us and until we all take action, the problem of acid rain will continue to persist.

Acid rain, or acid deposition is rain water with elevated levels of hydrogen (H+) ions. Acid rain refers to the ways in which acid moves from the atmosphere to the earth’s surface. It is transboundary and involves the falling of sulfuric or nitric acid. There are two different forms of acid deposition, one of them is wet deposition: acid rain, snow, and fog and dry deposition, which falls as separate acidic particles or gases. Acid rain occurs as a result of high pollution levels in the atmosphere. It is a chemical reaction caused as a result of emissions of sulfur dioxide and nitrogen oxides reacting with oxygen, water vapour, carbon dioxide and other substances in the atmosphere to form sulfuric and nitric acids. Sunlight is a factor that increases the rate of these reactions. The emission of these chemicals alters how gases in the atmosphere react with each other. Burning fossil fuels such as; oil, gas and coal, generate sulfur dioxide and nitrogen oxide gases and releases them into the atmosphere. Acid rain is most prevalent in areas of high sulfur dioxide and nitrogen oxide emissions. When air becomes more polluted with sulfur dioxide and nitrogen oxides, the acidity increases. Only ten percent of the pollution responsible for acid rain is from natural causes.

Measuring the Acidity of Rainwater Acidity is a measure of the concentration of hydrogen atoms in a solution. The pH scale measures the alkalinity and acidity of solution. A substance is considered to be an acid if they are below a pH of 7. The acidity of rain water comes from; carbon dioxide, nitrogen oxide and sulphur dioxide. Pure water is neutral and has a pH of 7. Rain water, due to the carbon dioxide in the air, is weakly acidic and has a pH of 5 to 6. Carbon dioxide contributes to the natural acidity of rainwater, as when it dissolves in water, the reactants are rearranged to form a carbonic acid. What are Sulfur Dioxide and Nitrogen Oxides? Sulfur dioxide and Nitrogen oxides are bi-products generated from the burning of fuels and gases. Sulfur dioxide; So2 is a chemical compound. It is released into the atmosphere through industrial activity. So2 is formed when materials containing sulfur are burned. Sulfur dioxide is a form of atmospheric pollution and if inhaled, can cause irritation to the nose, throat and airways.

Nitrogen oxides has a chemical symbol of No2. It is a highly reactive gas released into the earth’s atmosphere through manufacturing, oil refineries and fuel emissions from cars, trucks, busses and power plants. Inhaling air with a high concentration of Nitrogen oxides can disturb the functioning of the lungs and contribute to asthma, and other damaging respiratory conditions. Adverse Effects of Acid Rain Effects of acid rain on the Earth’s ecosystem Acid rain has many adverse effects on the earth’s ecosystem. Acid rain percolates into soils, dissolving magnesium or calcium; plants vital nutrients and releases toxic substances that influence how plants absorb water. Acid deposition also weakness trees, damages their leaves and limits the nutrients available to them. The inimical consequences of acid rain can be further observed in marine environments. Acid rain falls directly on aquatic habitats, and causes these environments to become more acidic. As the pH level of these areas decrease, the numbers and species of fish, plants and animals living in these aquatic habitats depreciate. Human health Acid rain does not directly affect human health. Sulfur dioxide and Nitrogen oxides react in the atmosphere to form sulfate and nitrate acids that can be inhaled by people. Scientific studies have shown a relationship between these particles and the effects they have on human health. Inhaling sulfur dioxide and Nitrogen oxides, can cause; heart attacks, increase the risk of heart disease, and affect lung function. Materials/surfaces Acid rain impairs any vulnerable material it lands on. Acid rain causes erosion to the surfaces of buildings and vehicles.

The effects of acid rain can be most notably observed on limestone, marble or sandstone as these rocks dissolve in acids and are therefore particularly affected by air pollution and acidic rain. History and Present of Acid Water The earliest account of acid rain was in 1852, by Robert Angus Smith. Robert was able to indicate the relationship between acid rain and atmospheric pollution. In the late 1960s scientists in England conducted further research into the chemical reaction, central causes, and consequences of acidic rain. Since the industrial revolution in the 1960s, emissions of Sulfur dioxide and Nitrogen oxides have increased and the acidity of rain as a result of the establishment of more industrial and energy generating facilities, has also increased. Scientists continue to perform studies into the complications associated with acid rain, and develop products to minimise the effects of Sulfur dioxide and Nitrogen oxides. Further research is currently being conducted into more innovative and environmentally sustainable ways to burn fuels in factories. Ninety percent of acid rain reactants are produced in factories. The only commercial benefit involved in the production of acid rain is the reduction in the cost of controlling the reactants released.

So2 scrubber are regularly installed in industrial factories to prevent the emissions of sulfur dioxide into the atmosphere, however it is cheaper for these industries to let the reaction happen in production, than to install these preventive devices. Acid rain can weaken the production of crops and pollute aquatic environments, poisoning fish. This creates further financial burdens in communities, business and the economy as a consequence of the damage inflicted by acid rain.

From the research conducted, I have been able to further my perceptions of the central causes and consequences of acid rain. Acid rain is water with elevated levels of hydrogen ions and can have adverse effects on the earth ecosystem, building materials, natural landforms and marine species. Although acid rain does not directly affect human health, the emission of sulfur dioxide and nitrogen oxides that react in the atmosphere to form sulfate and nitrate acids, can provoke irritation to the throat, ears and airways and damage to the heart and lungs. It is evident from the research conducted, that if in the future industrial facilities continue to burn fuels that generate sulfur and nitrogen oxides, the extent of the damage and the frequency of acid rain is going to increase. If scientists continue to perform studies into new ways of reducing the emissions of SO2 and NO2 in the atmosphere and develop new preventive devices, it may minimise the effects of acid rain in the future. It is however, evident that acid rain has already had many damaging consequences on the earth’s ecosystem and after evaluating the evidence, I can conclude that the only benefit of acidic rain is the reduction of methane emissions in the environment, helping to reduce the effects of global warming.

Introduction

Acid rain refers to rain containing strong inorganic acids in solution. The acids include sulfuric acid, ammonium and nitric acid. The acids originate from acid forming substances emitted into the atmosphere from combustion of hydrocarbon fuels and farming activities (Driscoll et al. 2005, p. 27). These chemicals interact with ozone and atmospheric moisture to form the acids which are incorporated into rain droplets and transferred to the earth’s surface.

This report explains the processes leading to acidic atmospheric deposition. It begins with a brief description of how acid rain is formed from acid forming substances emitted from the earth’s surface. A discussion of the effects of rain on ecosystems and man-made structures then follows. Acidic atmospheric deposition alters the chemistry of soil, strains vegetations, acidifies water bodies, dissolves limestone used in buildings, and corrodes metallic structures.

Formation of acid rain

Sulfuric acid is the main component of acid rain. The other components are nitric acid and ammonium. Sulfuric acid is formed by a chemical reaction involving sulfur and hydroxyl radicals (OH). Combustion of sulfur containing substances is a major source of atmospheric sulfur. Major contributors of atmospheric sulfur are power plants, automobile engines, and decomposing fertilizers.

It is emitted in various forms but the most commonly occurring forms are sulfur dioxide (SO2) and sulfur trioxide (SO3). Following emission, sulfur dioxide reacts with OH radicals from ozone photolysis to form SO3 (Goodarzi, Solimannejad & Vahedpour 2012, p. 1610). Photolysis of hydroxide is a complex processes involving break down of Ozone to form highly reactive oxide radicals which then react with water to from OH radicals. SO3 then attacks two water molecules to form sulfuric acid.

SO3 + 2H2O H2SO4

Nitric acid and ammonium are formed from gaseous compounds containing nitrogen molecules. Nitrogen dioxide is also emitted during combustion. Another source of nitrogen dioxide and nitric oxide is ammonium containing fertilizer. Ammonium fertilizers decay giving rise to the gases. The gases then undergo chemical changes in the atmosphere producing nitric acid.

Effects of acid rain

Acid rain causes a variety of changes in the ecosystems and man-made structures. It alters the chemical composition of soil, causes erratic growth of plants, and acidifies aquatic ecosystems. The effects are either direct or indirect. Direct effects include those that cause changes by themselves like alteration of soil composition. Indirect effects include depletion of fish food stocks in the aquatic ecosystems.

Effects of acid rain on soil

Acid deposition causes serious alteration in the chemical composition of soil. The alteration has serious consequences on plant growth especially in forests. Acid rain causes depletion of soil cations like calcium, magnesium, potassium and sodium. Acidification of soil by acid deposition causes the cations to be released and washed away by surface water.

At the same time, inorganic aluminum accumulates in the soil causing aluminum overload. Normally, cations originate from weathering and atmospheric deposition. The cations are then used by plants. Acid rain alters this cycle causing a situation in which the cations are washed away faster than they can be replenished through natural processes. Depletion of cations also makes it difficult to rid soil of added acids. Fertilizers like ammonium nitrate contain acids.

Other fertilizers may be modified in soil to form strong acids. Acid deposition also causes accumulation of sulfur and nitrogen. Excess sulfur and nitrogen creates conditions that do not support proper growth of plants. Excess sulfur and nitrogen can also be washed into water bodies where they undergo chemical reactions to produce acids. Sulfur reacts with water molecules to form sulfuric acid. The end result is the acidification of aquatic environment.

Effect of acid rain on vegetation

Acid deposition affects vegetation in two ways. First, it alters the chemical composition of soil thus depriving plants of essential nutrients. Acid rain causes leaching of cations which are important nutrients for plants. Therefore, acid rain causes growth retardation of some plants.

Second, acid rain dissolves cations in the leaves. This causes a significant strain on the plants. Growth of some plants becomes erratic. Acid deposition may also cause decreased decomposition of dead plants. Decomposition is an important means of nutrient recycling. Formation of humus is slowed down by acid rain. Decomposition appears to depend on cation-containing enzymes.

Effects of acid deposition on aquatic ecosystems

Acid rain causes acidification of water bodies like streams, rivers and lakes. Acidification of water bodies has profound effects on aquatic life. Most fish species cannot thrive in acidic environments (Mason 1994, p. 1250). In extreme cases, acidification of water causes sudden death of fish.

An indirect cause of the deaths is depletion of food. Algae and planktons which form a great percentage of fish food do not survive in acidic environments. This may cause complete elimination of all forms of aquatic life. Accumulation of leached aluminum in the water is also responsible for fish poisoning. Acidification of water bodies occurs over a long period of time. In some parts of the world it is thought that this process has been going on for over two hundred years. This implies that de-acidification will take a number of years.

Effects of acid deposition on man-made structures

Acid deposition corrodes metallic structures. The most affected metallic structures are those made of iron. Corrosion causes structural weaknesses thus endangering life. Structures made of limestone are also affected by acid deposition. Acid rain causes dissolution of calcium carbonate. Calcium carbonate is a constituent of limestone.

Over an extended period of time, it compromises the structural strength of buildings. This problem is particularly serious in some areas. This may be attributed to the fact that emission of acid forming substances is greater in some regions. In some regions building materials do not contain a lot of calcium carbonate.

Conclusion

This report discussed the formation and effects of acid rain. Acid rain is also known as acidic atmospheric deposition. Acid rain is formed when acid forming substances interact with ozone and water forming strong acids which are then transferred to the earth’s surface. Sulfuric acid is a major component of acid rain.

Sulfuric acid is formed following emission of sulfur from combustion. The gaseous form of sulfur exists in a variety of species. The most common being sulfur dioxide and sulfur trioxide. Sulfuric acid is formed by a chemical reaction between sulfur trioxide and hydroxyl radicals.

Acid rain acidifies water, alters soil composition, corrodes buildings, and strains plants. In addition to draining the soil of cations, it causes build up of soil sulfur and nitrogen. It also bleaches the cations from plant leaves. Acidification of water bodies alters aquatic ecosystems. This may cause deaths of all forms of aquatic life. Some fish species cannot thrive in acidic environments. Planktons and algae are a major source of food for small fish.