Acid Precipitation
Acid precipitation, also known as acid rain, refers to rainfall or any form of precipitation that has a higher acidity than normal. This increased acidity is often caused by pollutants such as sulfur dioxide and nitrogen oxides released into the atmosphere from human activities, particularly the burning of fossil fuels. Acid precipitation can have detrimental effects on the environment, including harming aquatic ecosystems and damaging buildings and monuments.
6 Key excerpts on "Acid Precipitation"
eBook - ePub- A. Ward Gardner(Author)
- 2013(Publication Date)
- Butterworth-Heinemann(Publisher)
...10 ACIDIC DEPOSITION D.W. Gardner Publisher Summary This chapter provides an overview on acid deposition. Acidic deposition—or acid rain—has been implicated as the cause of environmental damage in both Europe and North America, and has generated considerable public concern. Acidic or atmospheric deposition includes the dry deposition of the gases SO 2 and NO x themselves or of their reaction products, principally ozone (O 3) and aerosols, and the wet deposition of sulfates and nitrates in rain, snow, and fog, which may or may not be associated with acidity. The exact chemical form of acid deposition is controlled by a variety of atmospheric and environmental factors, and the susceptibility of the receptors, plants, soils, is similarly controlled by a multitude of environmental and man-made factors. The principal error in assessing the potential effects of acid rain on the ecosystem has been to equate the presence of sulfate and nitrate ions in rainfall as being exactly equivalent to the presence of sulfuric and nitric acids. INTRODUCTION Acidic deposition, or acid rain, has been implicated as the cause of environmental damage in both Europe and North America and as such has generated considerable public concern. Adverse effects attributed to acid rain are losses of fish from lakes and rivers in Norway, Sweden and parts of the north-eastern United States, the decline of forests in central and southern Germany, and acid damage to soils and buildings. Classically, these adverse effects were attributed to man-made emissions of sulphur dioxide (SO 2) and nitrogen oxides (NO x) which were converted to sulphuric and nitric acids in the atmosphere and eventually deposited into acid-sensitive ecosystems by rainfall...
eBook - ePubExploring Environmental Issues
An Integrated Approach
- David D. Kemp(Author)
- 2004(Publication Date)
- Routledge(Publisher)
...It falls most commonly as rain, but also includes snow, hail and fog, which together are considered as forms of wet deposition. In addition, it includes dry deposition, which involves the fall-out of oxides of sulphur and nitrogen from the atmosphere, either as dry gases or adsorbed on aerosols such as soot and fly-ash. In contact with moisture in the form of fog dew or surface water, they produce the same effects as the constituents of wet deposition (Mason 1990). The term ‘acid rain’ is normally used to include all forms of wet and dry deposition. Although acid rain is most often equated with modern industrial pollution, atmospheric moisture has always contained some level of acidity. Natural processes in the earth/atmosphere system create carbonic, sulphuric and nitric acids, and studies of rainwater chemistry in tropical northern Australia have identified organic acids such as acetic and formic acids as important contributors to atmospheric acidity (Bridgman 1994). When these acids fall out in the rain they become involved in a variety of physical and biological processes at the earth's surface. The return of nitrogen and sulphur to the soil in naturally acid rain helps to maintain nutrient levels, for example. Acid rain also makes a major contribution to the landscape in limestone areas, through the same processes of acid corrosion and solution that are responsible for the deterioration of buildings in urban centres. Current concern over acid rain is not with the natural variety, however, but rather with that produced by the acid gases emitted by modern industrial activities. Robert Smith, a British chemist, is normally credited with first recognizing the link between air pollution and the acidity of the atmosphere, in his observations of the chemistry of the rain falling in industrial Manchester in the mid-nineteenth century. In 1872 he wrote a book on the subject in which he made the first reference to ‘acid rain’ (Smith 1872)...
eBook - ePub- Rattan Lal(Author)
- 2017(Publication Date)
- CRC Press(Publisher)
...Acid Rain: Nitrogen Deposition George F. Vance Department of Renewable Resources, University of Wyoming, Laramie, Wyoming, U.S.A. Abstract Air pollution has occurred naturally since the formation of the earth’s atmosphere; however, the industrial era has resulted in human activities greatly contributing to global atmospheric pollution. One of the more highly publicized and controversial aspects of atmospheric pollution is that of acidic deposition. Acidic materials can be transported long distances, some as much as hundreds of kilometers. Acidic deposition can impact buildings, sculptures, and monuments that are constructed using weatherable materials like limestone, marble, bronze, and galvanized steel. While acid soil conditions are known to influence the growth of plants, agricultural impacts related to acidic deposition are of less concern due to the buffering capacity of these types of ecosystems. When acidic substances are deposited in natural ecosystems, a number of adverse environmental effects are believed to occur, including damage to vegetation, particularly forests, and changes in soil and surface water chemistry. INTRODUCTION Air pollution has occurred naturally since the formation of the earth’s atmosphere; however, the industrial era has resulted in human activities greatly contributing to global atmospheric pollution. [ 1, 2 ] One of the more highly publicized and controversial aspects of atmospheric pollution is that of acidic deposition. Acidic deposition includes rainfall, acidic fogs, mists, snowmelt, gases, and dry particulate matter. [ 3 ] The primary origin of acidic deposition is the emission of sulfur dioxide (SO 2) and nitrogen oxides (NO x) from fossil fuel combustion; electric power–generating plants contribute approximately two-thirds of the SO 2 emissions and one-third of the NO x emissions. [ 4 ] Acidic materials can be transported long distances, some as much as hundreds of kilometers...
eBook - ePubEnvironmental Policy and Public Health
Air Pollution, Global Climate Change, and Wilderness
- William N. Rom(Author)
- 2011(Publication Date)
- Jossey-Bass(Publisher)
...The additional acidity (between pH 5.6 and 5.1–5.3) was thought to be the result of natural emissions of S and N from, for example, volcanoes, lightning, wild fires, and stratospheric transport, in combination with other cations and anions in solution. They found that precipitation in remote sites was far more likely to be dominated by naturally occurring organic acids, such as formic and acetic acids, than that collected from eastern North America. Thus preindustrial rain has been shown to be quite different from postindustrial rain, and it is clear that human activities have led to acid deposition. In the United States, the trend for acid rain has been increasing since the 1950s, with most of the increase in the northeastern United States and acidity spreading into the Midwest. In 2011, the average pH of rain throughout North America, Europe, and other parts of the world is between 4 and 5 (100 µEq/L and 10 µEq H+/L, respectively), 30 though historically, precipitation events have been reported with pHs much lower than this (for example, pH 2.85 at HBEF). The changing trends in emissions of NOx and SO 2 have influenced the relative proportions of sulfuric and nitric acid in rain water: to wit, the ratio of sulfur to nitrogen in rain has shifted from 2:1 in 1980 to 1:1 in 2000. 31 Monitoring programs exist that are designed to measure and quantify atmospheric deposition in its various forms. Most of these programs were begun in the late 1970s in North America and until the past decade included only rain monitoring. One of the goals of these wet deposition-monitoring networks has been to gather sufficient data to quantify the deposition of pollutants and nutrients over large geographic regions. As a result, data now exist that show the geographic distribution of deposition of various ions in precipitation. It is clear from these data that for the United States wet deposition of various pollutants and nutrients varies across the country...
eBook - ePub- Zdenko Rengel, Zdenko Rengel(Authors)
- 2003(Publication Date)
- CRC Press(Publisher)
...4: Acid Inputs into the Soils from Acid Rain Christine Alewell University of Bayreuth, Bayreuth, Germany 1 INTRODUCTION Industrialized regions of the world have been confronted with the consequences of acidic deposition since the beginning of the 20th century. Today, there is substantial concern about the environmental impacts of air pollution on the local, regional, and global scale [ 1 ]. It has been shown that observed levels of various air pollutants can threaten human health, vegetation, wildlife, and soil biology; cause damage to materials; and change the chemistry of soils and waters. The term “acid rain” or “acid deposition,” which covers the wide range of physical, chemical, and biological processes involved in the issues of acidification, is defined here as the acid input to ecosystems and soils from the atmosphere originating in human activity (e.g., in fossil fuel burning). Although there is some question of whether any location on the earth is untouched by human activities in some way, the natural troposphere is usually referred to as the atmosphere over remote areas [ 2 ]. Thus, the anthropogenic pollution of the atmosphere, which is the origin of acid rain, always has to be assessed in comparison with the natural troposphere. Widespread regulatory action to curb air pollution was not taken until strong links were established between human health and pollutants in the mid-1900s. Until the 1950s, air pollution was emitted from relatively short smokestacks and had the most profound effects in areas immediately surrounding the source. In urban areas throughout the world, pollution events were both severe and frequent enough during this time period that they often led to human health problems [ 3 ]. One smog event in London in 1952 reportedly caused 4000 deaths [ 4 ]. In an effort to ameliorate the urban pollution situation, smokestack height was increased in North America and Europe between the 1950s and 1970s so that pollutants would disperse more widely...
eBook - ePubSoils and Groundwater Pollution and Remediation
Asia, Africa, and Oceania
- P. M. Huang, I.K. Iskandar(Authors)
- 2020(Publication Date)
- CRC Press(Publisher)
...The acid rain is of the sulfate type. Most of the soils that are likely to suffer from the effect of acid rain have small buffering capacities against acid input. These soils can undergo a series of chemical reactions with both hydrogen ions and sulfate ions. These features shall be dealt with in the present chapter. ACID RAIN Formation Coal combustion is responsible for most of the atmospheric pollution in China, especially in the big cities. In 1982, coal accounted for about 74% of the total energy production in China, with about 18%, 3%, and 5% contributed by oil, gas, and hydropower, respectively (Zhao and Xiong, 1988). An estimated 40% of the coal consumed was for industrial, commercial, and domestic use in cities, with an area totaling less than 0.5% of the whole country. Most of the coal used in cities is burned in medium-sized and small furnaces with low stacks without devices for removing SO 2 from flue gas. Thus, under unfavorable meteorological conditions, heavy pollution occurs in these areas. Furthermore, in regions where the ecosystem, including soil, is more sensitive to acid rain, the coal consumed is mostly high in sulfur content. In the south and the southwest, the S content of the coal is generally 2–3%, and in some areas it may be as high as 5% (Li, 1989; Zhang, 1985). The emitted SO 2, after undergoing chemical reactions in the air, transforms into H 2 SO 4 when dissolved in rainwater. This is the main reason for the appearance of sulfate-type acid rain. Besides, statistical data show that the percentage of nitrate ions in total anions in acid rain is slightly higher than that in nonacid rain, although the percentage is less than 15% of the total anions (Wang et al., 1989). This implies that NO x is also a contributing factor to the formation of acid rain in China. Distribution Table 8.1 shows the average pH of rainwater in some cities...
