Associate environmental consultant, Dow Chemical Co., Midland, MI
Pages: 10 Published: Jan 1988
There is scant information concerning the chemical composition of the mud-water interface in shallow, aerobic, eutrophic bodies of water. A little more is known of this region in deep eutrophic lakes with periodically anaerobic hypolimnions. The object of this paper is to compare the composition of the mud-water interface in two such limnological systems and to demonstrate the effect this region exerts on the chemical life of lakes.
The shallow lake used as an example is the preserve of Lake Huleh, Israel, which is hypereutrophic and rarely contains water to a depth greater than 35 cm but has an area of 46.9 ha (116 acres). Linsley Pond, Connecticut, will be used as an example of a deeper (14.6 m) eutrophic lake which is thermally stratified except for the autumnal and vernal isothermal periods.
In a shallow aerobic pond such as the Huleh Preserve, elements that are sorbed by the mud fall into two groups: those that are sorbed and retained by the organic matter, and those that move in concert with the ferric hydroxide complex. Under anaerobic conditions such as those present in Linsley Pond much of the year, those same elements diffuse from the mud into the hypolimnion.
Those elements held most strongly in the surface waters, as contrasted to the mud-water interface in shallow aerobic systems such as the Huleh Preserve, diffuse from the reduced mud surface in anaerobic systems such as Linsley Pond.
Some elements diffuse from a reduced mud surface and under aerobic conditions attain equilibrium. These are rubidium, lithium, and aluminum.
Sodium, boron, silicon, chromium, nickel, and chlorine do not diffuse from a reduced mud surface. In aerobic systems chlorine attains equilibrium, while in the shallow Huleh Preserve the sodium concentrates in the surface water. Boron, silicon, chromium, and nickel in shallow systems become enriched in surface waters in contrast to the liquid or solid portion of the mud-water interface.
All elemental concentrations reported in this study represent the total amount detected. Speciation is not addressed. The cyclical nature of elemental concentrations noted in this study should provide a much-needed background for sediment quality criteria.
mud-water interface, elemental composition, eutrophication, ferric hydroxide complex, organic matter, aquatic toxicology
Paper ID: STP10281S