The Scheldt estuary revisited: occurrence and behaviour of particulate polychlorinated biphenyls and polycyclic aromatic hydrocarbons
van Zoest, R.; van Eck, G.Th.M. (1999). The Scheldt estuary revisited: occurrence and behaviour of particulate polychlorinated biphenyls and polycyclic aromatic hydrocarbons. Grontmij Advies & Techniek bv, adviesgroep Bodem: Houten. 12 + tabellen + figuren pp.
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Document type: Final report
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| Keywords |
Chemical compounds > Organic compounds > Hydrocarbons > Unsaturated hydrocarbons > Aromatic hydrocarbons
Pollutants > Hazardous materials > Chemical pollutants
Europe, Schelde R. [Marine Regions]
Marine/Coastal; Brackish water |
| Abstract |
Temporal and spatial variations in particulate PolyChlorinated Biphenyl (PCB) and Polycyclic Aromatic Hydrocarbons (PAH) concentrations were studied in the Scheldt estuary during a one-year period (May 1995-June 1996). This sampling campaign was arecurrence of a campaign held almost a decade ago. Both PCB and PAH concentrations in the Scheldt river were substantially lower in the 90's, but the Scheldt is still one of the most severely polluted rivers in the North Sea area. The annual input into the estuary was approximately 40 kg for total PCBs (sum of 8 congeners) and 3300 kg for total PAHs (19 compounds). The fraction transported to the North Sea is relatively small: 10-20 %.In the most recent sampling campaign the behaviour of particulate PCBs and PAHs found earlier was confirmed: as a result of the mixing of riverine with marine particulates the concentrations of the micropollutants generally decrease with increasing salinities, The quicker restoration of dissolved oxygen in the upper estuary gave rise to a more intense degradation of organic matter, and, probably as a result of cometabolism, degradation of low molecuiar weight PAH. Typical calculated half lives were 260 days for pyrene and 390 for fluoranthene. |
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