Streams acidification

Since SO2 and NO2 are criteria pollutants, their emissions are regulated. In addition, for the purposes of abating acid deposition in the United States, the 1990 Clean Air Act Amendments require that nationwide SO2 and NO emissions be reduced by approximately 10 million and 2 million t/yr, respectively, by the year 2000. Reasons for these reductions are based on concerns which include acidification of lakes and streams, acidification of poorly buffered soils, and acid damage to materials. An additional major concern is that acid deposition is contributing to the die-back of forests at high elevations in the eastern United States and in Europe. 

In some sensitive lakes and streams, acidification has completely eradicated fish species, such as the brook trout, leaving these bodies of water barren. In feet, hundreds of the lakes in the Adirondacks surveyed in the NSWS have aridity levels indicative of chemical conditions unsuitable for the survival of sensitive fish species. 

Baldigo B. P. and Murdoch P. S. (1997) Effect of stream acidification and inorganic aluminum on mortality of brook trout Salvelinus fontinalis) in the Catskill mountains. New York. Can. J. Fish Aquat. Sci. 54, 603-615. 

Jenkins A., Cosby B. J., Perrier R. C., Walker T. A. B., and Miller J. D. (1990) Modelling stream acidification in afforested catchments—an assessment of the relative effects of acid deposition and afforestation. J. Hydrol. 120, 163-181. 

Norton S. A., Wagai R., Navratil T., Kaste J. M., and Rissberger F. A. (2000) Response of a first-order stream in Maine to short-term in-stream acidification. Hydrol. Earth Syst. Sci. 4, 383-391. 

In 1987 Dr. Ken Simmons tested rainbow trout in the waters of Whetstone Brook in MA. He discovered that when the pH was 5.97, the trout did not spawn. Along with other scientists, he started an experiment to reduce the acidity of the stream by adding calcium carbonate, or limestone, in measured amounts. The calcium carbonate reacts with acid but is not toxic to the environment and does not risk raising the pH too much. The experiment caused the pH to rise to 6.54 over a three-year period. As a result the population of trout in the treated area increased and their health improved. According to Dr. Simmons, this is not a permanent solution, but rather a band-aid approach to the problem of stream acidification by acid rain. 

Whitehead, P.G., Neale, R. Paricos, P. (1987) Modelling stream acidification in upland Wales. In Systems Analysis in Water Quality Management (ed. Beck, M.B.). Pergamon, Oxford. 

The acid chloride obtained as described above was dissolved in dry acetone (10 ml) and added in a steady stream to a stirred solution of 6-aminopenicillanic acid (1.08 g, 5 mmol) in a mixture of N sodium bicarbonate (15 ml) and acetone (5 ml). After the initial reaction the reaction mixture was stirred at room temperature for 45 minutes, then washed with ether (3 X 25 ml). Acidification of the aqueous solution with N hydrochloric acid (11 ml) to pH 2 and extraction with ether (3 x 15 ml) gave an ethereal extract which was decolorized with a mixture of activated charcoal and magnesium sulfate for 5 minutes. 

The liberated bromine is carried by a stream of air into an alkaline solution of sodium carbonate where it dissolves as a mixture of bromide and bromate [the analogy of reaction (79)]. This last step serves to concentrate the product, and free bromine is obtained by subsequent acidification of the solution, through the reaction... 

There are many ways the acidification of lakes, rivers and streams harm fish. Mass fish mortalities occur (during the spring snow melt) when highly acidic pollutants— that have built up in the snow over the winter—begin to drain into common waterways. Such happenings have been well documented for salmon and trout in Norway. 

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