Consulta: creatorFacets:"Baeyens, W.F.J."
Registros recuperados: 32
Data/hora: 16/06/2024 10:16:38

Behaviour of heavy metals in a mud flat of the Scheldt estuary, Belgium
Provedor de dados: 27
Autores: Panutrakul, S.; Baeyens, W.F.J.
The Ballasplaat intertidal mud flat in the Scheldt estuary has been polluted by Cd and Pb and also high amounts of organic matter as a result of suspended matter deposition. The degree of pollution is, however, not uniform over the mud flat due to varying physico-chemical conditions (essentially variable redox profiles). Measurements of the redox profile, and the metal concentrations in the pore water, the total sediment and the fraction &lt;63 µm combined with sequential extraction results and enrichment factors can explain the behaviour of Cd, Pb, Fe and Mn in the sediments. In a strong anoxic sediment, where sulphate reducing bacteria are active, the heavy metals are trapped as poorly soluble metal complexes while in an oxic or suboxic sediment metals...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cadmium Chemical reactions Estuaries Iron Lead Manganese Marine pollution Mud flats Physicochemical properties Sediment chemistry Sediment pollution Sediments ANE; Netherlands; Westerschelde; Ballastplaat.
Ano: 1991
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3112

Distribution of particulate trace elements in the Northeastern Atlantic
Provedor de dados: 27
Autores: Dauby, P.; Baeyens, W.F.J.; Biondo, R.; Bouquegneau, J.-M.; Chou, L.; Collette, O.; Dehairs, F.A.; Elskens, M.; Frankignoulle, M.; Loijens, M.; Paucot, H.; Wollast, R.
From 1989 to 1992, five cruises were conducted in an area covering the English Channel, the Celtic Sea and the Gulf of Biscay. During these campaigns, suspended matter was collected by different techniques in order to analyze the spatial and vertical distribution of several particulate trace elements in relation to the global biogeochemical cycle of carbon. It appears that horizontal distribution varies strongly from one element to another and is mainly influenced either by  anthropogenic and terrigenous inputs or by scavenging processes. On the other hand, the vertical distribution seems mainly linked to the primary production. In parallel to these trace element measurements, experiments were carried out to estimate the transfer rates of these elements...
Tipo: Info:eu-repo/semantics/article
Ano: 1993
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2680

Effect of organic complexation on the behaviour of dissolved Cd, Cu and Zn in the Scheldt estuary
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Goeyens, L.; Monteny, F.; Elskens, I.
Samples from the Scheldt estuary have been assayed for dissolved Cd, Cu and Zn using differential pulse anodic stripping voltammetry, either as total (after UV irradiation) or labile concentrations. Under these experimental conditions, labile concentrations ranged between 51-65% of total Cu, 16-66% of total Zn and 53-91 % of total Cd. The metal-organic interactions were assessed by evaluating (a) the distribution coefficient K&lt;sub&gt;d&lt;/sub&gt; for the distribution of the metals between the liquid phase (complexation) and their binding to particulate matter, and (b) the competitive effect exerted by inorganic complexing ligands using a multi-element interaction model. The proportion of organically bound metals (strong and labile) was estimated, in...
Tipo: Info:eu-repo/semantics/article
Ano: 1998
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7051

Boundary conditions for heavy metals at the air-sea interface
Provedor de dados: 27
Autores: Dehairs, F.A.; Dedeurwaerder, H.; Dejonghe, M.; Decadt, G.; Gillain, G.; Baeyens, W.F.J.; Elskens, I.
During 1980 and 1981 the aerosol burden as well as the wet and dry atmospheric fall-out of Cu, Cd, Pb, Zn, Fe and Mn to the sea have been studied in the Belgian coastal area. Atmospheric Cu, Zn and Cd are observed to be introduced into the sea mainly by wet fall-out, while Fe, Mn and also Pb have a dry and wet fall-out of similar magnitude. Of these elements, Cu, Zn and Cd have the highest washout factors. Furthermore, for all elements, excepted Mn, discrepancies exist between washout factors above land and sea, with values up to 5 times larger above the sea.On the scale of the North Sea, atmospheric fall-out of Cu, Zn, Pb and Cd exceeds by one order of magnitude the combined input of the rivers Scheldt, Rhine and Meuse, while fall-out of Fe and Mn is of...
Tipo: Info:eu-repo/semantics/article
Ano: 1982
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=10065

General description of the Scheldt estuary
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Van Eck, B.T.M.; Lambert, C.; Wollast, R.; Goeyens, L.
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...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: ANE; Netherlands; Westerschelde.
Ano: 1998
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7040

Distribution, transport and fate of Bi, Cu, Cd, Hg, Pb, Sb and Zn in the Belgian coastal marine environment. Part IV: The river Scheldt as a transport route of heavy metals to the sea
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Wartel, S.; Dehairs, F.A.; Decadt, G.; Bogaert, M.; Gillain, G.; Dedeurwaerder, H.
Tipo: Info:eu-repo/semantics/article
Ano: 1982
URL: http://www.vliz.be/imisdocs/publications/286409.pdf

Preparation method for solid samples with low nitrogen content for spectrometric nitrogen-15 analysis
Provedor de dados: 27
Autores: Goeyens, L.G.; Stichelbaut, L.W.; Post, E.J.; Baeyens, W.F.J.
A new procedure for the conversion of bound nitrogen into nitrogen gas, applicable to solid material, is described. It embodies two main stages: the catalytic ammonification of the sample and the consecutive transformation of ammonium to molecular nitrogen by the modified Dumas method. The first step of the preparation is carried out in a quartz reactor, filled with granular nickel, at a temperature of 700°C, the ammonia gas produced being trapped in sulphuric acid. In the second step, this solution is neutralised, dried and subjected to the Dumas combustion.The addition of reagents does not influence the results of the measurements. Spectrometric &lt;sup&gt;15&lt;/sup&gt;N percentage abundances are converted into mass spectrometric "true"...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Emission spectroscopy.
Ano: 1985
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3279

Biogeochemical behaviour of Cd, Cu, Pb and Zn in the Scheldt estuary during the period 1981-1983
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Elskens, M.; Gillain, G.; Goeyens, L.
Cu, Zn, Cd and Pb have been analysed in suspended matter and water samples from the Scheldt estuary, collected during five cruises between May 1982 and May 1983. In order to evaluate the overall metal behaviour in the estuary, continuous longitudinal profiles of the total, the particulate and the dissolved metal concentrations are discussed in relation to various specific physico-chemical parameters. By means of correlation and multi-regression techniques, several estuarine processes could be identified which dominate and/or control the behaviour of the individual trace metals in three distinct areas of the Scheldt estuary. The behaviour of the four selected metals was found to show some common features, but is besides this also characterised by many...
Tipo: Info:eu-repo/semantics/article
Ano: 1998
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7043

Improvement of the semiautomated headspace analysis method for the determination of methylmercury in biological samples
Provedor de dados: 27
Autores: Lansens, P.; Baeyens, W.F.J.
An improvement in the extraction step in the method of Decadt et al. for determining methylmercury in biological tissues is described. The methylmercury is released from the tissue by use of sulphuric acid as the cleaving agent and immediately converted to the iodide form by iodoacetic acid. These reaction steps take place in a closed headspace vial. The methylmercury iodide is then headspace-injected into a gas-chromatograph and detected with a microwave-induced plasma detector. Quantitation is accomplished by standard addition. Analysis of one sample takes less than 15 min. The detection limit of the method is 20 ng methylmercury per gram biological tissue when 50 mg of tissue are taken.
Tipo: Info:eu-repo/semantics/article
Ano: 1990
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3091

Accumulation of suspended barite at mesopelagic depths and export production in the Southern Ocean
Provedor de dados: 27
Autores: Dehairs, F.A.; Baeyens, W.F.J.; Goeyens, L.
Tipo: Info:eu-repo/semantics/article
Ano: 1992
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=10162

The impact of the Scheldt input on the trace metal distribution in the Belgian coastal area (results of 1981-1983 and 1995-1996)
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Elskens, I.; Van Ryssen, R.; Leermakers, M.
Offshore fluxes of Cu, Zn, Cd, Pb and Hg were calculated based on residual flow patterns and salinity gradients along the Belgian coast. The residual flow lines along the Belgian coast are more or less parallel to the coast except the area where the north-easterly flowing water mass coming from the Channel encounters the south-westerly-oriented Scheldt outflow, forming a residual hydrodynamical front. From the steady-state salinity pattern, diffusion coefficients perpendicular to the residual flow were deduced; they ranged from 21 to 108 m² s-¹ . Offshore fluxes of dissolved and particulate trace metals based on diffusive and mixing processes are calculated. The steady state profiles of dissolved metals show a dilution effect in the coastal waters,...
Tipo: Info:eu-repo/semantics/article
Ano: 1998
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7055

Quantitative in-situ microanalysis of minor and trace elements in biogenic calcite using infrared laser ablation - inductively coupled plasma mass spectrometry: a critical review
Provedor de dados: 27
Autores: Vander Putten, E.; Dehairs, F.A.; André, L.; Baeyens, W.F.J.
Tipo: Info:eu-repo/semantics/article
Ano: 1999
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=10258

The leading role of ammonium in the nitrogen uptake regime of Southern Ocean marginal ice zones
Provedor de dados: 27
Autores: Goeyens, L.; Dehairs, F.A.; Tréguer, P.; Bauman, E.M.; Baeyens, W.F.J.
The nitrogen signature of marginal ice zones in the Southern Ocean often departs from the "classical" Antarctic nutrient profiles with high nitrate and low ammonium values in the surface layer. Weddell Sea marginal ice zones e.g. show enhanced nitrate depletions, amounting to similar to 500 mmol N m super(-2). Additionally, ammonium stocks in the upper layer can be up to 7% of the inorganic nitrogen pool. The corresponding nitrogen uptake regime suggests elevated nitrate assimilation during the early phase of the productive season and significantly reduced nitrate assimilation at a later stage. Absolute as well as specific nitrate uptake rates decrease by an order of magnitude when ammonium stocks exceed 1.7% of the total inorganic nitrogen. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Algal blooms Ammonium compounds Ice cover Marginal seas Nitrogen cycle Phytoplankton Primary production PS; Antarctic Ocean.
Ano: 1995
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=10188

The biogeochemical behaviour of Cd, Cu, Pb and Zn in the Scheldt estuary: results of the 1995 surveys
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Parmentier, K.; Goeyens, L.; Ducastel, G.; De Gieter, M.; Leermakers, M.
Cd, Cu, Zn and Pb concentrations in both dissolved and particulate phase were assessed during 1995. Data Quality Assurance was an integral part of this study and involved all major steps of the analysis procedure such as sampling, sample handling, preconcentration and determination. Desorption and redox processes clearly control the dissolved Cu and Cd profiles. Mobilisation of dissolved Zn is small and essentially restricted to the low salinity area and the late spring survey. Dissolved Pb shows the clearest dilution pattern. The parameters representative of these processes (dissolved oxygen and salinity) also correlate very well with the particulate metal profiles. In addition, the plankton activity (expressed by the chlorophyll-&lt;i&gt;a&lt;/i&gt;...
Tipo: Info:eu-repo/semantics/article
Ano: 1998
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7046

Determination of methylmercury in natural waters by headspace gas chromatography with microwave-induced plasma detection after preconcentration on a resin containing dithiocarbamate groups
Provedor de dados: 27
Autores: Lansens, P.; Meuleman, C.; Leermakers, M.; Baeyens, W.F.J.
A method for the determination of methylmercury at ng 1&lt;sup&gt;-1&lt;/sup&gt; levels in natural waters is described. Methylmercury present in a sample is first preconcentrated on a column of a resin containing dithiocarbamate groups and eluted quantitatively with acidic thiourea solution. Methylmercury in the effluent is then converted to the iodide by addition of sulphuric acid and iodoacetic acid and determined by headspace gas chromatography with microwave-induced plasma detection. The adsorption properties of the resin are discussed.
Tipo: Info:eu-repo/semantics/article
Ano: 1990
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3092

Investigation of headspace and solvent extraction methods for the determination of dimethyl- and monomethylmercury in environmental matrices
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Leermakers, M.; Molina, R.; Holsbeek, L.; Joiris, C.R.
Aqueous distillation is a common initial step in the determination of monomethyl mercury (MMHg) in a variety of matrices. However, recently it was observed that during distillation, MMHg may be generated from inorganic mercury and induce in some cases significant analytical errors. Therefore we investigated a number of alternative analytical techniques for the determination of MMHg in sediments and biological tissues: (1) headspace-GC-AFS and some variants; (2) acid extraction-solvent extraction-GC-AFS; (3) acid extraction-solvent extraction-GC-ECD. Methods (2) and (3) showed MMHg generation when an inorganic Hg spike was added to the sediment sample. The headspace method yielded MMHg results in agreement with the reference values for biological and...
Tipo: Info:eu-repo/semantics/article
Ano: 1999
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=6829

Nitrogen cycling and budget in Belgian coastal waters: North Sea areas with and without river inputs
Provedor de dados: 27
Autores: Mommaerts, J.-P.; Pichot, G.; Ozer, J.; Adam, Y.A.; Baeyens, W.F.J.
The coastal sea off Belgium has been extensively studied for a number of years on a multidisciplinary basis. Thus the stocks within the system's various compartments as well as the carbon or nitrogen fluxes between them resulting from biological activity at several trophic levels have been measured. Further, the tidal and residual circulations have been investigated and modeled in addition to the erosive properties of the flow. There are strong differences between the more coastal part of this area and the open sea. In particular, inputs from rivers and channels seem to exert an influence beyond what could normally be expected in coastal areas.Adequate modelling of the nitrogen cycle in such a diverse environment demanded a fine approach, including a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrogen cycle River inflow ANE; Belgium; Belgian Coast ANE; North Sea; Southern Bight.
Ano: 1984
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3333

Trace metals in the eastern part of the North Sea: 1: Analyses and short-term distributions
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Gillain, G.; Decadt, G.; Elskens, I.
Advanced analysis procedures for dissolved and particulate trace metals in sea water have been developed and tested in international intercalibration exercises. Since these tests gave evidence that reliable data could be produced with such methods, trace metal distributions in the coastal waters of the eastern North Sea were studied.The spatial distributions of most dissolved and particulate trace metals are, at least qualitatively, similar. Their concentrations decrease with distance from the coast and the mouth of the Scheldt estuary ( particulates much stronger than dissolved species). The salinity gradient is similar (but opposite) to the trace metals and turbidity gradients. The five trace metals studied can be subdivided into two groups on the basis...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Analytical techniques Coastal zone Dissolved chemicals Quantitative distribution Salinity Suspended particulate matter Trace metals Turbidity ANE; North Sea.
Ano: 1987
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3284

Determination of methylmercury in biological samples by semiautomated headspace analysis
Provedor de dados: 27
Autores: Decadt, G.; Baeyens, W.F.J.; Bradley, D.; Goeyens, L.
Gas-liquid distribution coefficients of methylmercury halides dissolved in water or benzene have been assessed by using a headspace injection system coupled to a gas chromatograph-microwave-induced plasma system. Vapor concentrations decreased in the following order: CH&lt;sub&gt;3&lt;/sub&gt;HgI &gt; CH&lt;sub&gt;3&lt;/sub&gt;HgBr &gt; CH&lt;sub&gt;3&lt;/sub&gt;HgCl. To transform all methylmercury iodide, iodoacetic acid (IAc) is used as the liberating agent. Methylmercury iodide degradation is prevented by the addition of sodium thiosulfate (0.05 M). The results obtained with internal standard addition are not influenced by other volatile compounds including other mercury compounds. The method has been applied to a series of biological samples. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Analytical techniques; Chemical analysis; Mercury compounds.
Ano: 1985
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3198

A box-model of metal flows through the Scheldt estuary (1981-1983 and 1992-1995)
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Monteny, F.; Van Ryssen, R.; Leermakers, M.
The behaviour of Cu, Zn, Cd, and Pb in the Scheldt estuary was investigated in the periods 1981 to 1993 and 1995. The Hg behaviour was studied between 1992 and 1994. A box model was used to establish the relationship between the trace metal inputs and the fate of these pollutants in the Scheldt estuary. Annual budgets were calculated for particulate and dissolved trace metals. For Hg, seasonal budgets of the various species (inorganic Hg, methylmercury, Hg°) could also be calculated. These budgets allow an evaluation of the consistency of each individual flux or process, such as the inputs of the various metals into the North Sea, the sedimentation flux of particulate metals in the area of high turbidity, the evasional fluxes and the formation rates of...
Tipo: Info:eu-repo/semantics/article
Ano: 1998
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7059

Trace metals in the eastern part of the North Sea: 2. Flows of Cd, Cu, Hg, Pb and Zn through the coastal area
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Gillain, G.; Ronday, F.; Dehairs, F.A.
The residual flow lines of the Belgian coast are more or less parallel to the coast except in the area where the northeasterly flowing watermass coming from the Channel encounters the southwesterly-oriented Scheldt outflow. The result is a residual hydrodynamical front with, at the northern side, a less saline estuarine watermass, and at the southern side a more saline marine watermass. From the steady-state salinity pattern, diffusion coefficients perpendicular to the residual flow were deduced; they ranged from 21 to 108 m².s&lt;sup&gt;-1&lt;/sup&gt;.The steady-state profiles of dissolved metals versus salinity indicate a dilution effect in the coastal-estuarine watermass and almost constant concentration in the marine watermass. Offshore fluxes of Cd,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coastal zone Trace metals ANE; North Sea.
Ano: 1987
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3156

An automated method for the assessment of mercury adsorption rates on particulate suspended matter
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Decadt, G.; Dehairs, F.A.; Goeyens, L.
A continuous filtration system connected to a mercury auto-analyzer has been constructed for obtaining mercury adsorption rates on particulate suspended matter. The capabilities of this device have been demonstrated by carrying out a series of experiments under controlled physicochemical parameter conditions on samples of the Scheldt estuary. Duplicate measurements showed coefficients of variation ranging from 1 to 6 %. Depending on the physico-chemical conditions, the initial adsorption rate per unit of dissolved mercury concentration varied between 1.2 and 8.1 x 10&lt;sup&gt;-2&lt;/sup&gt; mn&lt;sup&gt;-1&lt;/sup&gt;.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Adsorption; Mercury; Methodology; Particulates; Suspended matter.
Ano: 1982
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3413

Particulate trace metals above the Southern Bight of the North Sea: 1. Analytical procedures and average aerosol concentrations
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Dedeurwaerder, H.
Heavy metal concentrations in total particulate suspended matter and size fractionated particulate suspended matter above the Southern Bight of the North Sea have been assessed. Most of the samples were collected from a light vessel; the total sampling period covered about 70 days at sea. Stringent precautions were taken during sampling, storage, handling and analysis of the samples. As a conclusion, we found that on a long-term basis the aerosol concentrations above the North Sea have a fairly homogeneous composition, but short-term variations probably resulting from point emissions were observed. The cascade impactor results indicated that Pb, Cu, Cd and Zu were carried by submicrometer aerosols, Na, Fe, Mn and Al by supermicrometer aerosols. Most of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aerosols Air pollution Atmospheric particulates Meteorology Seasonal variations Statistical analysis Trace metals Troposphere Winds ANE; North Sea; Southern Bight.
Ano: 1991
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3106

Tight coupling between enrichment of iron and manganese in North Sea suspended matter and sedimentary redox processes: evidence for seasonal variability
Provedor de dados: 27
Autores: Dehairs, F.A.; Baeyens, W.F.J.; Van Gansbeke, D.
Suspended matter and sediments from the North Sea were analysed for Al, Fe and Mn. A seasonal variation of Mn and Fe over Al ratios is observed. For most of the year suspended matter is enriched in Mn and Fe relative to average soil composition. No enrichment, and even depletion, occurs during a short period of the year (April-May) coinciding with the occurrence of the spring phytoplankton bloom. Surface sediments from the Southern Bight show the inverse image, with Mn and Fe enrichment occurring only in April-May and no enrichment during the rest of the year. These observations suggest a tight coupling between: (1) the change of redox potential in surface sediments, as triggered by the advection of organic matter from the spring bloom; (2) the outflow of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ferromanganese oxides Iron compounds Manganese compounds Redox reactions Seasonal variations Sediment chemistry Suspended load ANE; North Sea.
Ano: 1989
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3010

Particulate trace metals above the Southern Bight of the North Sea: 2. Origin and behaviour of the trace metals
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Dedeurwaerder, H.
Ninety-six aerosol samples were collected in all seasons and wind conditions in the troposphere of the Southern Bight of the North Sea. About one third of these samples were collected with a six stage cascade impactor sampler. Considering that in each sample metals were analyzed, the data set we had to handle consisted of about 2000 results. In addition, wind directions and wind speeds are also included in this data set. To interpret all these results, we relied upon two methods: (1) enrichment factors were calculated and allowed us to identify some of the metal sources; (2) three factors resulted from a multivariate analysis method: in the first factor we only find Na, representing the marine component; the second factor includes Al (a crustal and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aerosols Air pollution Atmospheric particulates Meteorology Seasonal variations Statistical analysis Trace metals Troposphere Winds ANE; North Sea; Southern Bight.
Ano: 1991
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3109

Behaviour and speciation of mercury in the Scheldt estuary (water sediments and benthic organisms)
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Meuleman, C.; Muhaya, B.; Leermakers, M.
Surface waters, sediments and the polychaete &lt;i&gt;Nereis diversicolor&lt;/i&gt; were sampled in the Scheldt Estuary between 1990 and 1994. In surface waters particulate Hg (Hg&lt;sub&gt;p&lt;/sub&gt;) concentrations ranged from 350-1610 ng g-¹. They are essentially controlled by physical mixing of polluted fluvial particulates with relatively unpolluted marine particulates, but unaffected by seasonal changes. Dissolved Hg species, on the other hand, show large seasonal variations essentially controlled by the redox conditions in the estuary, as well as by bacterial and phytoplankton activity. Total dissolved (Hg&lt;sub&gt;TD&lt;/sub&gt;) concentrations ranged from 0.5 to 3.0 ng l-¹ with 10 to 90% as reactive Hg. High concentrations of...
Tipo: Info:eu-repo/semantics/article
Ano: 1998
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7047

Ammonium regeneration in the Scotia-Weddell Confluence area during spring 1988
Provedor de dados: 27
Autores: Goeyens, L.; Tréguer, P.; Lancelot, C.; Mathot, S.; Becquevort, S.; Morvan, J.; Dehairs, F.A.; Baeyens, W.F.J.
Tipo: Info:eu-repo/semantics/article
Ano: 1991
URL: http://www.vliz.be/imisdocs/publications/279128.pdf

Estimates of dry and wet deposition and resuspension fluxes of several trace metals in the Southern Bight of the North Sea
Provedor de dados: 27
Autores: Dedeurwaerder, H.L.; Dehairs, F.A.; Decadt, G.; Baeyens, W.F.J.
In this study we have investigated air-sea exchanges in the Belgian coastal area located in the Southern Bight of the North Sea. Since 1980 the tropospheric aerosol contents for the trace elements Cd, Cu, Mn, Pb, Zn and for the reference elements Al , Fe, Na have been monitored on an intermittent basis from a maritime sampling platform (Light-Vessel West-Hinder; position: 51°23.5'N- 2°21.5'E, fig. 1). During 1981 sampling campaigns at sea were paralleled by sampling campaigns on land, in the coastal area (natural reserve De Blankaert, located at 20 Km inland), in order to allow for a better evaluation of the specific source or sink role of the sea. No major source of pollution exists between the maritime and the continental sampling sites. During these...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aeolian deposits Resuspension Trace metals ANE; North Sea; Southern Bight.
Ano: 1984
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3323

Dynamic patterns of dissolved nitrogen in the Southern Bight of the North Sea
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Mommaerts, J.-P.; Goeyens, L.; Dehairs, F.A.; Dedeurwaerder, H.; Decadt, G.
Spatial and temporal variations of dissolved inorganic nitrogen (DIN) have been assessed in onshore and offshore areas of the Southern Bight on the basis of several years' measurements. They indicate that both the residual flow lines and DIN isoconcentration lines run parallel with the coast except in the vicinity of important freshwater discharge points such as the Scheldt estuary. Evidence was found that the seasonal DIN oscillations are not created through fluctuations in input conditions at the lateral boundaries, despite considerable fluctuations in these inputs which include the English Channel (from 500 tons(t) N day&lt;sup&gt;-1&lt;/sup&gt; in June up to approximately 2000 t N day&lt;sup&gt;-1&lt;/sup&gt; in February) and also rivers such as the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dissolved organic nitrogen ANE; North Sea; Southern Bight.
Ano: 1984
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3310

Comparative study of different wet mineralisation digestion methods for the measurement of total mercury in biological samples
Provedor de dados: 27
Autores: Dehairs, F.A.; Decadt, G.; Baeyens, W.F.J.
Three botanical substrates and one milkpowder were mineralised and digested by the following methods in order to measure their total mercury content:  (1) HF/HNO&lt;sub&gt;3&lt;/sub&gt;-KMnO&lt;sub&gt;4&lt;/sub&gt;; (2) H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;/HNO&lt;sub&gt;3&lt;/sub&gt;-KMnO&lt;sub&gt;4&lt;/sub&gt;; (3) H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;/HNO&lt;sub&gt;3&lt;/sub&gt;- H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;; (4) H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;/HNO&lt;sub&gt;3&lt;/sub&gt;-UV irradiation/KMnO&lt;sub&gt;4&lt;/sub&gt;; (5) H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;/HNO&lt;sub&gt;3&lt;/sub&gt;/V&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;-catalyst...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Digestion; Mercury; Nutrients (mineral).
Ano: 1982
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3380

Distribution, transport and fate of Bi, Cu, Cd, Hg, Pb, Sb and Zn in the Belgian coastal marine environment. Part V: Interaction kinetics between dissolved inorganic mercury and estuarine suspended matter
Provedor de dados: 27
Autores: Baeyens, W.F.J.; Decadt, G.; Dehairs, F.A.; Goeyens, L.; Dedeurwaerder, H.; Gillain, G.
Tipo: Info:eu-repo/semantics/article
Ano: 1982
URL: http://www.vliz.be/imisdocs/publications/286410.pdf

Evolution of trace metal concentrations in the Scheldt estuary (1978-1995): a comparison with estuarine and ocean levels
Provedor de dados: 27
Autores: Baeyens, W.F.J.
Dissolved and particulate metal concentrations assessed in the Scheldt estuary in the period 1978-1995, yield a clear indication that the levels of all metals decreased significantly. A comparison with other estuaries classifies the Scheldt as being moderately polluted for all metals in the dissolved phase, but as being fairly high polluted in the particulate phase, especially for Cd. However, even the dissolved metal concentration fractions in the Scheldt are still between 10 to 50 times enriched compared to total metal concentrations in unpolluted seas and oceans.
Tipo: Info:eu-repo/semantics/article
Ano: 1998
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7067