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Arsenic in Lake Lansing, michigan
Author(s) -
Batterson Ted R.,
McNabb Clarence D.
Publication year - 1983
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620020101
Subject(s) - anoxic waters , arsenic , environmental chemistry , arsenite , arsenate , sediment , environmental science , sodium arsenite , phosphate , dry weight , aeration , macrophyte , chemistry , geology , oceanography , biology , botany , paleontology , organic chemistry
Lake Lansing was treated with sodium arsenite for macrophyte control in 1957. Two 2.5‐m cores from deep portions of the basin showed the historical consequence of this treatment. Maxima of 330–340 μg As g −1 dry weight occurred at a depth interval of 0.15–0.30 m; background was 17–20 ppm As. An arsenic mass balance budget for the lake for June 1978 to June 1979 showed it lost more arsenic than it received. Internal loading of the water from the sediments was occurring; > 85% of the area of surficial sediments had concentrations two to six times background. From laboratory experiments, we hypothesize Fe 3+ controls arsenic concentration over aerobic sediments; As(III) increases in anoxic water with conversion of Fe 3+ to Fe 2+ and As(V) to As(III) at the sediment surface. As(III) in water diminishes during prolonged anoxia by reaction with S 2− . As(III) and Fe 2+ are oxidized upon aeration of anoxic water, and As(V) is taken out of solution with ferric iron in a manner similar to phosphate. Arsenic concentrations observed in the lake over an annual cycle fit these expectations.