In 1972, Likens et al. identified acid precipitation in eastern North America. G. E. Likens and F. H. Bormann (1974) demonstrated its regional distribution in the eastern United States and indicated that the transformation of nitrogen oxides (NO
x), as well as sulfur dioxide (SO
2), adds to precipitation acidity. D. W. Schindler and his colleagues (1985) performed a whole lake acidification in Canada and documented the adverse decline of the lake food web at pH levels as high as 5.8. The issue of acid rain or deposition has generated a vast amount of knowledge and understanding of atmospheric and watershed processes, and research in the field continues today.
Formation and Trends
The formation of acidic deposition is largely from the combustion of fossil fuels and the smelting of sulfide ores. Minor natural sources exist such as the formation of hydrochloric and sulfuric acid from gaseous volcanic eruptions.
There are well over 100 gaseous and aqueous phase reactions that can lead to acid formation and more than fifty oxidizing agents and catalysts may be involved. However, in the simplest terms sulfur in fuels is oxidized to SO 2, and SO 2 in the atmosphere is further oxidized and hydrolyzed to sulfuric acid.
This is a free page. This page contains 178 words. This
article contains 2,882 words (approx. 10 pages at 300
words per page).
Read the rest of this Article with our Acid Rain Access Pass.
