Geochemical processes in muddy and sandy tidal flat sediments

Baeyens, Willy; Panutrakul, Suwanna; Elskens, Marc; Leermakers, Martine; Navez, Jacques; Monteny, F.

doi:10.1007/bf02431011

Cited by 21 publications

(12 citation statements)

References 5 publications

(1 reference statement)

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“…-Coprecipitation and adsorption on ironhydroxides: a coupling between sedimentary redox processes and enrichment of iron and manganese in North Sea suspended matter has been reported by Dehairs et al (1989). A similar study was carried out on Scheldt sediments by Panutrakul & Baeyens (1991) and Baeyens et al (1991), and they observed reprecipitation of iron and manganese oxyhydroxides at the oxic/suboxic interface in the sediments. Zwolsman (1992) confirms the enrichment of iron and manganese in the suspended matter of the high turbidity zone in the Scheldt by typical pore water gradients across the sediment-water interface in that area of 421 mM cm ,1 for Fe and 45 mM cm ,1 for…”

Section: Upstream Estuary: the Geochemical Filtersupporting

confidence: 53%

“…-Oxidation of resuspended metal sulphides: in the reduced sediments in zone 2-10 psu, the oxidisable fraction (metal sulphides and metals bound to the organic matter) constitutes a major fraction according to the general accepted sequential extraction schemes (Panutrakul & Baeyens, 1991;. Due to the strong tidal action and the presence of fine muddy sediments, metal sulphides can be resuspended.…”

Section: Upstream Estuary: the Geochemical Filtermentioning

confidence: 99%

See 1 more Smart Citation

General description of the Scheldt estuary

Baeyens¹,

Eck²,

Lambert

et al. 1998

Trace Metals in the Westerschelde Estuary: A Case-Study of a Polluted, Partially Anoxic Estuary

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A general description of the Scheldt estuary, including the hydrology, the sediment transport, the productivity and the biodegradation with respect to their influence on the trace metal behaviour in the Scheldt estuary, is given.The river basin can be divided in several sections according to their morphological, hydrodynamical and sedimentary properties. The zone from km 78 to 55, which corresponds roughly with the salinity zone from 2 to 10 psu, is the zone of high turbidity, high sedimentation and of oxygen depletion, especially in the summer period. That area is called the geochemical filter because the solid/dissolved distribution of the trace metals is controlled by redox, adsorption/desorption, complexation and precipitation/coprecipitation processes. The sedimentation rate in that area is estimated at 280 Mkg y ,1 .In the downstream estuary the phytoplankton activity increases due to the restoration of oxygen and to the much lower turbidity values. That area is called the biological filter because incorporation of trace metals by the plankton communities lowers the trace metal concentrations during the productivity period, while transformation of metal species, especially observed with mercury, occurs during that period too.

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Section: Upstream Estuary: the Geochemical Filtersupporting

confidence: 53%

Section: Upstream Estuary: the Geochemical Filtermentioning

confidence: 99%

General description of the Scheldt estuary

Baeyens¹,

Eck²,

Lambert

et al. 1998

Trace Metals in the Westerschelde Estuary: A Case-Study of a Polluted, Partially Anoxic Estuary

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“…However, the differences in concentrations of PCBs in sediments are not only due to anthropogenic impacts, but also to the organic content and grain size of the sediment. It is well-known that sediments having a high organic matter content but also a high proportion of the fine grain size fraction (< 2 μm) accumulate far higher amounts of pollutants than sandy sediments (Baeyens et al, 1991). The findings from this study revealed that high concentrations of PCB congeners were related to organic matter, silt and fine sand.…”

mentioning

confidence: 47%

Characterization of polychlorinated biphenyls in surface sediments of the North End Lake, Port Elizabeth, South Africa

Kampire

Rubidge

Adams

2017

WSA

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The distribution and concentrations of 6 indicator polychlorinated biphenyl (PCB) congeners, nos. 28, 52, 101, 138, 153 and 180, were determined in surface sediments from the North End Lake in Port Elizabeth, South Africa. Forty-two surficial sediment samples were collected from different locations covering the region that receives the majority of the industrial waste, urban effluents and runoff and thus expected to be contaminated with different degrees of contamination. The analysis was achieved by gas chromatography-mass spectrometry (GC/MS) using the internal standard method. The total PCB concentrations in the samples ranged from 1.60 to 3.06 ng·g -1 dry weight (dw). The concentrations of congener profiles showed significant differences. Generally, the highest PCB concentrations were associated with high organic matter contents and small grain size. The highly chlorinated PCBs dominated with regards to the levels in sediments. PCB 138 was the major contributor to the total PCBs and was detected at 100% of sites. This study provided a snapshot of the PCB contamination status in the North End Lake sediments, and allowed for a comparison between the investigated system and other systems worldwide.

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“…1-5 mL of the solution was transferred to a purging bottle, 1 mL 10% (w/v) SnCI2 was added and the sample solution was then purged with argon during 3 minutes at a flow rate of 500 mL/min. Mercury vapour was trapped onto a gold-coated sand column (Baeyens and Leermakers, 1989). The gold column was then heated to 450 ~ for 2 minutes and the mercury vapour was swept into the atomic absorption detector at a flow rate of 300 mL/min and measured by cold vapour atomic absorption spectrometry (CVAAS), using a Kipp Analytica Mercury Vapour Monitor (Kipp Analytica).…”

Section: Methodsmentioning

confidence: 99%

Total mercury and methylmercury in sediments and in the polychaeteNereis diversicolor at Groot Buitenschoor (Scheldt estuary, Belgium)

Muhaya¹,

Leermakers²,

Baeyens³

1997

Water Air Soil Pollut

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Abstract. Total mercury (Hg) and methylmercury (MeHg) concentrations were determined in sediments and in the polychaete worm Nereis diversicotor at 13 stations of a brackish water intertidal nmdflat of the Scheldt estuary. Hg and MeHg concentrations in sediments ranged from 144 to 1192 ng g-~ dw and from 0.8 to 6 ng g-~ dw, respectively. Both Hg and MeHg concentrations increased with an increase of organic matter (OM) content and fine grain fraction. In contrast, Hg accumulation hy N. diversicolor was significantly (p < 0.05) higher at stations with sandy sediments (mean value: 125 ng g-i dw) than at stations with muddy sediments (mean value, 80 ng g-~), probably because Hg availability for bioaccumulation at muddy stations was reduced by high OM content of the muddy sediments. MeHg accounted for an average of 0.7% of the total Hg in sediments and 18% of the total Hg in N. divelwicolor. Seasonal variations significantly affected Hg concentrations in sediments and MeHg in N. divezwicotor. Total Hg concentrations in sediments were significantly (p < 0.05) higher in autumn and winter than in spring and summer whereas MeHg concentrations were lowest in winter compared to the other seasons. On the other hand, total Hg concentrations in the worms were lowest in spring whereas MeHg concentrations were significantly (p < 0.01) higher in spring and summer than in autumn and winter.

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Geochemical processes in muddy and sandy tidal flat sediments

Cited by 21 publications

References 5 publications

General description of the Scheldt estuary

General description of the Scheldt estuary

Characterization of polychlorinated biphenyls in surface sediments of the North End Lake, Port Elizabeth, South Africa

Total mercury and methylmercury in sediments and in the polychaeteNereis diversicolor at Groot Buitenschoor (Scheldt estuary, Belgium)

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