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Mechanisms of hydrogen ion neutralization in an experimentally acidified lake
Author(s) -
Cook R. B.,
Kelly C.A.,
Schindler D.W.,
Turner M. A.
Publication year - 1986
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1986.31.1.0134
Subject(s) - alkalinity , hypolimnion , sulfate , sulfuric acid , environmental chemistry , chemistry , anoxic waters , ammonium , inorganic chemistry , eutrophication , organic chemistry , nutrient
The experimental acidification of Lake 223 (Experimental Lakes Area, northwestern Ontario) with sulfuric acid in 1976–1983 allowed a detailed examination of the capacity of the lake to neutralize hydrogen ion. A whole‐lake alkalinity and ion budget for Lake 223 showed that 66– 81% of the added sulfuric acid was neutralized by alkalinity production in the lake. Nearly 85% of in situ alkalinity production was accounted for by net loss of sulfate through bacterial sulfate reduction, coupled with iron reduction and iron sulfide formation, in littoral sediments (60%) and in the hypolimnion (25%). Exchange of hydrogen ion for calcium and manganese in the sediments accounted for 19% of the alkalinity generated, while other cations were net sinks for alkalinity. Alkalinity input from the watershed of Lake 223 was very small, averaging about 5% of that produced in the lake. The seasonal production of 1,000 µ eq liter −1 alkalinity in the anoxic hypolimnion of this softwater lake could be attributed to bacterial sulfate reduction coupled with iron sulfide formation, ammonium production, and iron (II) production. Only the alkalinity produced from bacterial sulfate reduction coupled with iron sulfide formation remained throughout the annual cycle.