Effects of Acid Rain

T FIGURE 15.17 The Effscts of Acid Rain (a) Buildings, gravestones, and statues damaged by acid rain are a common sight in the northeastern United States and in many other industrialized nations, (b) Some species of trees are highly susceptible to the effects of acid rain. 

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M = Al, Ga, In, Tl). The solution chemistry of Al in particular has been extensively investigated because of its industrial importance in water treatment plants, its use in many toiletry formulations, its possible implication in both Altzheimer s disease and the deleterious effects of acid rain, and the ubiquity of Al cooking utensils.For example, hydrated aluminium sulphate (10-30 gm ) can be added to turbid water supplies at pH 6.5-7.5 to flocculate the colloids, some 3 million tonnes per annum being used worldwide for this application alone. Likewise kilotonne amounts of A1(OH)2.5C1o.5 in concentrated (6m) aqueous solution are used in the manufacture of deodorants and antiperspirants. 

The effects of acid rain are particularly severe in areas where the bedrock is granite or other materials incapable of neutralizing H+ ions. As the concentration of acid builds up in a lake, aquatic life, from algae to brook trout, dies. The end product is a crystal-clear, totally sterile lake. 

Effect of acid rain on a marble statue of George Washington in New York City. The... 

The human impact on the environment affects many areas of our lives and future. One example is the effect of acid rain on biodiversity, the diversity of living things. In the prairies that extend across the heartlands of North America and Asia, native plants have evolved that can survive even nitrogen-poor soil and drought. By studying prairie plants, scientists hope to breed food plants that will be hardy sources of food in times of drought. However, acid rain is making some of these plants extinct. 

Likens, G.E., Driscoll, C. T. and Buso, D. C. (1996). Long-term effects of acid rain response and recovery of a forest ecosystem. Science 272, 244—246. 

Explain how titration might be used to deter- 2. Explain how titration might be used for mine the effects of acid rain on the medical testing,... 

Buildings and statues constructed of marble are sensitive to the destructive action of acid rain. How can the same reactions that destroy marble be used to help reduce the harmful effects of acid rain pollution ... 

Environmental Effects of Acid Rain. Acid Rain Program, United States Environmental Protection Agency, http //www.epa.gov/airmarkets/acidrain/index.html... 

A trout fishery added limestone to their loch to combat the effects of acid rain. They managed to increase the pH of the water from 4 to 6. The concentration of H (aq)... 

A method sometimes used to counteract the effects of acid rain is the addition of a basic substance that wiii neutraiize the water s acidity, iime in the example shown here, to a body of water. (Martin Bond/Photo Researchers, inc.)... 

Higher pH of meltwater may act to lessen the effects of acid rain and snow. 

York and New England are devoid of fish due to the effects of acid rain. Indirect effects of the low pH values associated with acid rain also affect organisms. As noted in Table 13.1, one of the properties of an acid is the ability to dissolve certain metals. This has a profound effect on soil subjected to acid rain. Acid rain can mobilize metal ions such as aluminum, iron, and manganese in the basin surrounding a lake. This not only depletes the soil of these cations disrupting nutrient uptake in plants, but also introduces toxic metals into the aquatic system. 

The detrimental effects of acid rain are a major reason why legislation such as the Clean Air Act places strict limitations on sulfur and nitrogen emissions. It is also a reason why low sulfur coal is preferred over high sulfur coal. To reduce sulfur dioxide emissions, industry also uses a technique call scrubbing. Industrial scrubbers employ a variety of physical and chemical processes to remove sulfur dioxide from emissions. Another technique used to combat acidification of lakes is to treat these systems with lime. The lime acts to neutralize the acid, but such techniques are usually costly and are only a temporary remedy for combating the problem. 

The effects of acid rain can be seen in lakes and streams, in forests, and on all kinds of structures. The lowered pH kills fish eggs, fish, and many other organisms that live in lakes and streams. In forests, the acid can kill the leaves and needles of trees. It damages the soil by depleting it of nutrients, which stunts plant growth. Acid rain also eats away at the surfaces of buildings and other structures. Structures made of marble and other calcium-containing stone are particularly sensitive to acid rain. 

The two photographs in (a) show the same obelisk before and after the effects of acid rain, (b) Many forests downwind from heavily industrialized areas, such as in the northeastern United States and in Europe, have been noticeably hard-hit by acid rain. 

Hutterman, A.and D. Godbold Effects of Acid Rain on Forest Processes. John Wiley Sons, Inc, New York, NY, 1994. 

Among the many dramatic effects of acid rain are the extinction of fish from acidic lakes throughout parts of the northeastern United States, Canada, and Scandinavia, the damage to forests throughout much of central and eastern Europe, and the deterioration everywhere of marble buildings and statuary. Marble is a form of calcium carbonate, CaC03, and, like all metal carbonates, reacts with acid to produce C02. The result is a slow eating away of the stone. 

Lead content of petrol limited to 0.4 gl 1 Introduced to control the transboundary effects of acid rain and to limit emission of acidifying pollutants Air quality limit values and guide values for sulphur dioxide and suspended particles Limit value for lead in the air... 

Money has been made available to solve the problem of acid rain. Attempts are being made to clean gases being released from power stations and to look into ways in which the effects of acid rain can be reversed. The table below and Figure 12.5 (p. 199) give some data about the emission of sulfur dioxide. 

Taylor FB, Symons GE. 1984. Effects of acid rain on water supplies in the Northeast. J Am Water Works Assoc 76 34-42. 

Growing concern over environmental effects of acid rain has resulted in increased Interest in development of pre-combustion removal of sulfur from coal. Physical coal cleaning processes are effective for pyritic sulfur removal but do little to reduce the organic sulfur content of coal This paper reports the removal of organic sulfur from coal, employing ethyl or methyl alcohols as the solvent/ reactant. The process is based on the observation that, under supercritical conditions, reactions occur that selectively remove organic sulfur from the coal matrix. 

In recent years, the effects of acid rain on lake water, heavy metals contaminated soils and structural materials have been widely discussed (1). Sulfur and nitrogen contained in fossil fuels are released into the atmosphere by combustion. Sulfur and nitrogen oxides dissolve in rain drops as bisulfite, sulfite and nitrite ions. These components are further oxidized into sulfate and nitrate ions. Since these species lower pH, it is important to accurately determine them in rain water. However, these ions are difficult to analyze because they rapidly oxidize in the presence of catalysts such as ferric and manganous ions. Light, temperature, and pH also affect the oxidation rate of S(IV). 

Metals may become locked up in the bottom sediments of aquatic systems by chemical reactions, where they may remain for many years. However, metal solubility increases if the pH falls and they become more mobile. In fact, one of the knock-on effects of acid rain is the transport of metals to lower levels in the soil profile, where they may damage deep-rooted plants and contaminate groundwater. A... 

AP+ become predominant (through dissolution of Fe(OH)3, etc.) the toxic effects of acid rain involve the leaching of such metal ions into the water. Correspondingly, the widespread nature of iron deficiency is related to the precipitation of the moderately acidic Fe + ion at the pHs found in the intestine. 

The damaging effects of acid rain can be seen by comparing these photos of a decorative statue on the Field Museum in Chicago. The photo on the left was taken c. 1920 the photo on the right was taken in 1990. Recent renovation has since replaced the deteriorating marble. 

One harmful effect of acid rain is the deterioration of structures and statues made of marble or limestone, both of which are essentially calcium carbonate. The reaction of calcium carbonate with sulfuric acid yields carbon dioxide, water, and calcium sulfate. Because calcium sulfate is marginally soluble in water, part of the object is washed away by the rain. Write a balanced chemical equation for the reaction of sulfuric acid with calcium carbonate. 

An effect of acid rain in streams is to increase the amount of filamentous algae. It is doubtful, however, that it is a case of direct action resulting from the composition of the water, rather than being due to a decrease in herbivorous animals. As acidification increases, the number of animal species in the water decreases. There is a sharp reduction in herbivorous insects, while in the case of carnivorous insects no such dramatic result can be seen. 

In some cases the effects of acid rain can be partly offset by the hardness of water. One can take as an example the harmful effect of acid rain on mollusks tests, less evident in lakes containing harder water. 

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