The river Weser: Processes affecting the behaviour of metals and organochlorines during estuarine mixing
Duinker, J.C.; Hillebrand, M.T.J.; Nolting, R.F.; Wellershaus, S. (1982). The river Weser: Processes affecting the behaviour of metals and organochlorines during estuarine mixing. Neth. J. Sea Res. 15(2): 170-195
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, meer
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| Auteurs | | Top |
- Duinker, J.C.
- Hillebrand, M.T.J.
- Nolting, R.F.
- Wellershaus, S.
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| Abstract |
Measurements of dissolved and particulate suspended metals and organochlorine compounds were made along with studies on hydrographic and sedimentation-resuspension processes in the fresh water and the estuarine mixing zone of the tidal river Weser during typical spring tide conditions. The position of the mixing zone was 20 km upstream of its normal position as result of the extremely low river discharge in the dry summer of 1976. Concentrations of Cd, Zn, Cu, Pb, Mn and Fe in solution in the mixing zone increased by contributions from interstitially dissolved components during resuspension of bottom sediments. We interpret variations in the contents of metals in seston (weight to weight) in terms of varying contributions of different fractions that had different sedimentation and resuspension characteristics (i.e. different settling velocities in situ ) as well as different chemical composition. A wide range of PCB components with high and low degree of chlorination was present in solution and in suspension. Suspended particles were the most important carriers for components with higher degrees of chlorination. Concentrations of individual PCB components in fresh water varied between a few picograms per litre and the nanogram per litre range. The only compounds present in the estuary and the Wadden Sea above the detection limit in 1 litre samples were α- and -hexachlorocyclohexane in the low- and sub-ng.l-1 range. |
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