The biogeochemical cycling of trace metals in the water column of Lake Sammamish, Washington: Response to seasonally anoxic conditions

Limnology and Oceanography
By: , and 

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Abstract

Total acid‐soluble and dissolved Cd, Co, Cr, Cu, Ni, Pb, and Zn concentrations in the water column of a seasonally anoxic lake (Lake Sammamish, Washington) were measured on a monthly basis during the course of a year. These data, in conjunction with Fe, Mn, sulfide, and nutrient data, are used to assess the biochemical processes controlling the distribution of trace metals in the lake and how the importance of these processes varies with time. Thermodynamic calculations are used to examine changes in dissolved metal speciation in the bottom waters during the year and to assess the saturation state of metal‐sulfide phases. Spatial and temporal changes in the redox conditions of the bottom waters result in increases in dissolved Co and Ni concentrations, peaks in particulate Co profiles, decreases in dissolved Cu and Cr concentrations, and significant changes in dissolved metal speciation during stagnation. The redox‐driven cycling of Fe and Mn in the hypolimnion has a dramatic effect on Co distributions, a slight effect on Ni concentrations, and virtually no effect on Cd, Cu, Cr, and Zn concentrations. Biological uptake and regeneration processes result in a correlation between Zn and silicate concentrations throughout the water column, and it appears that biological cycling may also influence the distribution of Cd. During the sulfidic phase of stagnation dissolved Cd concentrations in the bottom waters may be controlled by metal‐sulfide precipitation, Cr(VI) is probably reduced to more particle‐reactive Cr(III) and removed by settling particles, and Cu(II) is most likely reduced to Cu(I) and precipitated as a metal‐sulfide phase.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The biogeochemical cycling of trace metals in the water column of Lake Sammamish, Washington: Response to seasonally anoxic conditions
Series title Limnology and Oceanography
DOI 10.4319/lo.1992.37.3.0529
Volume 37
Issue 3
Year Published 1992
Language English
Publisher American Society of Limnology and Oceanography
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center
Description 20 p.
First page 529
Last page 548
Country United States
State Washington
County King County
Other Geospatial Lake Sammamish