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Currently Skimming:

Predicting the Dispersion and Fate of Contaminated Marine Sediments
Pages 166-177

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From page 166...
... Once in the water column, contaminants may be transported by the threedimensional turbulent flow field away from the contaminated site while adsorbed onto the fine sediment particles ~ _ _ Thus' in order to quanticactve~y assess One tong-term rate or contaminants at a contaminated marine site (e.g., New Bedford Harbor, Massachusetts and Puget Sound, Washington) , it is essential to be able to perform a mass balance study for the fine sediments within the water body.
From page 167...
... The difficulties of comprehensive field studies and the deficiencies of some laboratory studies are discussed. The use of comprehensive models to assist the quantification of sediment dispersion processes is illustrated with a brief discussion of the laboratory studies of erosion and deposition using rotating annul)
From page 168...
... Although much research is still needed to understand the hydrodynamic processes, our current understanding on the estuarine circulation and advection process is much better compared to what we know about the other sediment dispersion processes. Numerous estuarine hydrodynamic and dispersion studies have been performed in the major estuaries in the United States and other countries.
From page 169...
... In shallow estuarine environments, turbulence may exist over the entire water column, including the bottom boundary layer and the surface boundary layer to enhance the mixing of various materials. Turbulent transport within the bottom boundary layer plays the important roles in affecting sediment erosion and deposition, while turbulent mixing throughout the water column can affect the flocculation and,settling of sediment particles .
From page 170...
... Comprehensive field data are needed in order to derive an erosion model and a deposition model for application with Eq.
From page 171...
... It is clear that comprehensive field monitoring in such an environment presents tremendous difficulties. Ideally, we would like to measure the vertical profiles of all the following parameters within the bottom boundary layer and the surficial sediments: mean velocity, turbulence, salinity, temperature, suspended sediment concentration, density, size distribution, settling velocity, benthos, pore pressure, and sediment composition.
From page 172...
... While measurement of turbidity and optical scattering at selected locations can be obtained with existing instruments, the accurate determination of suspended sediment concentration and particle size distribution is still unresolved and remains the topic of many researchers. Due to the difficulties of field measurements, erosion and deposition processes have been studied in laboratory using rotating annul)
From page 173...
... which compares 10 erosion models compiled in the form of E = a|~|0 where r is the dimensionless bottom stress. Curve is determined from Puget Sound field data by Lavelle et al., curves 3 and 4 are determined from laboratory experiments of Lake Erie sediments (Sheng and Lick, 1979)
From page 174...
... These models can then be combined with the circulation model, wave model, and bottom boundary layer model to produce an overall sediment dispersion model (Figure 7) , which may then be used for field validation and massbalance predictions.
From page 175...
... 2. A comprehensive field program at a contaminated marine site to allow monitoring of the extent of contamination and to allow development of field-based models of sediment dispersion processes: due to the availability of more advanced instrumentation and modeling technique, this study should yield results which are much more useful than previously possible under the DMRP program.
From page 176...
... 1988. Field Observations of the coastal bottom boundary layer under surface gravity waves.
From page 177...
... Paper presented at the Contaminated Marine Sediments Symposium, Marine Board, National Research Council. Tampa, May 31-June 2, 1988.


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