Acid rain extent

Acid Rain A National Sensitivity Assessment, Inland Waters Directorate, Environment Canada, Ottawa, Ontario, Fact Sheet and maps, 1988. Berden, M. Nilsson, S.I. Rosen, K. Tyler, G. Soil Acidification Extent, Causes, and Consequences, National Swedish Environmental Protection Board, Rept. 3292, 1987, pp 164. 

In the 20 years since the Brunddand report, great developments have taken place in industries toward sustainable practices. As a case in point, the problem of acid rain, an issue of concern in 1987, has improved to a large extent, thanks to catalytic pollution abatement both in stationary and automotive emissions. Catalysis for Green Chemistry and Engineering will continue to have a cracial role in improving the environmental performance of industry [25-27]. Nowadays, catalytic procedures are often implemented according to the green chemistry... 

Dust (especially from industrial activities) and salt spray will also exacerbate atmospheric corrosion (Section 16.4). In enclosed industrial premises, atmospheric corrosion could be minimized by preventing noxious emissions, filtering the air to remove particulate matter, and scrubbing the air with water to remove SO2 and other objectionable gases, although the humidity should itself be kept as low as possible (e.g., steam leaks should not be tolerated). On the global scale, however, the cost to the public of atmospheric corrosion could be substantially reduced by sharply limiting SO2 and, to a lesser extent, NO. emissions from power plants, smelters, automobiles, and other industrial functions. This is an aspect of the acid rain threat (Chapter 8) that is usually overlooked. 

Acids, and to a lesser extent bases, are part of our conversations, advertisements, and concerns. Headlines and television screens inform and persuade us about acid reflux, acid rain, cleaning compounds, and antacids (Figure 11.1). As you work your way through this unit and learn about acids and bases, you will find yourself looking at their presence in the world around you with a new awareness. 

Acid rain as a result of the burning of fossil fuels is an enormous environmental problem in sensitive areas. The situation has improved somewhat during recent years as a result of desulphuration of oil and the installation of scrubbers, etc. for removal of SO2, but the handling of NO (to a great extent produced from different transports) is more difficult. Furthermore, NO is produced through incorporation of atmospheric nitrogen during the combustion process. 

Synthetic acid rain samples have been allowed to percolate through pieces of coquina, the material of construction at Castillo de San Marcos National Monument, St. Augustine, Florida. Chemical analyses of the solutions are used to determine the extent of dissolution of the coqiuna, a limestone material, by acid rain. Because of the location of the Castillo on the Atlantic coast, the effect of salt spray on weathering of coquina appears to be as significant as the influence of acid rainfall. 

Not all v/oods i< y show a predisposition to invasion by disease pathogens and insects. As Scheffer and Cowling (51.) pointed out, woods do vary in the extent to which they will inherently resist heartwood decay. Certain types of oak and redwood are resistant to decay while some pines, birches and hickories are slightly or not resistant to heartwood decay. Two of the members of this slightly or not resistant decay category did show surface deterioration in work done by Banks et al. (49). It seems feasible that wood from these trees could be affected by acid rain and possibly other pollutants in combination with light and water. The result of this multiple factor interaction may then be impacted by insects or diseases. 

Finally, EPA must be granted under whatever resolution is ultimately chosen a high degree of flexibility to cope with the wide variations in the extent of knowledge concerning environmental effects and the characteristics of the control problem. All or nothing approaches will lead to acid rain-type impasses. The benefits of tailoring responses to the data at hand... 

Our principal sources of energy - fossil fuels - are all contaminated to some extent with sulfur compounds. When these fuels are burned, the sulfur compounds are burned to sulfur oxides, which are emitted to the atmosphere in the flue gas. In the atmosphere, these oxides are converted into the sulfur acids that are a principal cause of acid rain. 

Snlfur dioxide, and to a lesser extent nitrogen oxides, generated mainly from the bnming of fossil fuels and from the roasting of metal sulfides, causes acid rain. 

Important as a basis for developing general scientific understanding and at times consensus within Europe on the nature and extent of acid rain problem... 

In the biosphere, rain that is not lost back to the atmosphere by evaporation from the ground or from trees may pass deep underground, only to emerge at a much later date (Table 2.27) in a river or lake. Water coming into contact with rocks (and derived soils) reacts with primary minerals contained in them. The minerals dissolve to varying extents, and some of the dissolved constituents react with one another to form new, secondary minerals. Dissolution is mainly controlled by the water acidity provided from plant mineralization (humic acids), atmospheric carbonic acid and acid rain . The overall process is called chemical weathering (see Chapter 2.2.2.5, Eqs. 2.62 and 2.62 Berner and Berner 1996). 

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