A time-dependent flow model for heavy metals in the Scheldt estuary
Related to:De Smedt, F.; Vuksanovic, V.; Van Meerbeeck, S.; Reyns, D. (1998). A time-dependent flow model for heavy metals in the Scheldt estuary, in: Baeyens, W.F.J. (Ed.) Trace metals in the Westerschelde Estuary: a case-study of a polluted, partially anoxic estuary. Developments in Hydrobiology, 128: pp. 143-155. https://dx.doi.org/10.1007/978-94-017-3573-5_9, more
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| Authors | | Top |
- De Smedt, F., more
- Vuksanovic, V., more
- Van Meerbeeck, S., more
- Reyns, D.
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| Abstract |
The main processes that determine the behaviour of heavy metals in the Scheldt estuary are tidal hydrodynamics, sediment transport, and sorption of heavy metals on suspended matter. The water quality model WASP is applied to simulate the spatial distribution of five heavy metals in the estuary, under average hydrodynamic and suspended sediment transport regimes. First, the hydrodynamical part of the model is constructed and the results are verified by comparison with measured water levels and flow velocities. Secondly, a salt transport model is set up in order to evaluate the hydrodynamical dispersive mixing characteristics. Thirdly, a suspended sediment transport model is constructed and finally a transport model for heavy metals. The simulated distributions of the sorbed amounts of heavy metals, suspended sediment and salinity in the estuary agree well with observations. The calculated profiles of dissolved and sorbed concentrations of heavy metals in the water column indicate an accumulation of heavy metals in the zone of the turbidity maximum, while closer to the sea the concentrations diminish due to mixing of the polluted fluvial sediments with unpolluted marine sediments and because of sediment deposition in the estuary. It can be concluded that only a small part of the heavy metals reaches the sea. |
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