Mobilization of major trace elements at the water-sediment interface in the Belgian coastal area and the Scheldt Estuary
Baeyens, W.; Gillain, G.; Hoenig, M.; Dehairs, F. (1986). Mobilization of major trace elements at the water-sediment interface in the Belgian coastal area and the Scheldt Estuary, in: Nihoul, J.C.J. (Ed.) Marine interfaces ecohydrodynamics: proceedings of the 17th International Liège Colloquium on Ocean Hydrodynamics. Elsevier Oceanography Series, 42: pp. 453-485. dx.doi.org/10.1016/S0422-9894(08)71059-6
|
| Available in | Authors |
|
Document type: Conference paper
|
| Authors | | Top |
- Baeyens, W., more
- Gillain, G.
- Hoenig, M., more
- Dehairs, F., more
|
|
|
| Abstract |
In a shallow coastal area such as the Belgian coastal waters, a quite large amount of suspended matter reaches the bottom where a part of it is mobilized and released into the overlying water. Heterotrophic bacterial degradation of POM (Particulate Organic Matter), which is essentially limited to the first centimeters of the sediments, is the process, which is responsible for that mobilization. The presence or absence of dissolved iron and manganese depends on the redox state, anoxic or oxic, respectively. of the sediment. The behaviour ofstrontium in the first centimeters seems to be almost independent of POM degradation as well as redox conditions. The percentages of excess' Cu, Zn and Cd remobilized during the transition from suspended matter to the first centimeters of the bottom sediments are very high (100. 80 and 70% respectively) and independent of the type of sediment, suggesting POM is their carrier. Pb is more reluctant to mobilization and shows a higher mobilization percentage in anoxic sediments, suggesting that dissolution of Fe and Mn phases also releases a significant part of the solid Pb content. Epibenthic fluxes of Cd, Cu, Pb and Zn have been estimated in two different ways: (1) by considering a similar behaviour between the metal and POM for which remobilisation rates are known and (2) by using vertical pore water data profiles. Both estimates agree fairly well for Cu, Zn and Cd, but they differ significantly for Pb. |
|
