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  • 101
    Electronic Resource
    Electronic Resource
    Selenium associations in estuarine sediments: Redox effects (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 275-282 
    Details
    ISSN: 1573-2932
    Keywords: selenium ; sediment ; estuaries ; sequential extraction ; redox potential
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Selenium (Se) is a contaminant of concern in environments affected by discharges from smelting and coal-burning industries. Experiments hate been performed to investigate the phase associations of selenium in contaminated sediments under a range of controlled redox conditions. In this study, Se sediment associations were examined using the BCR sequential extraction technique after stabilisation at different redox states. It was shown that although most of the sediment-bound Se is associated with the operationally-defined “organic sulfide” fraction, as the measured redox potential of the system is increased. more Se moves into the “exchangeable” and “iron manganese oxy hydroxide” fractions. In these fractions. contaminants can be expected to be more bioavailable. As the mass of Se absorbed to sediments is typically at least an order of magnitude higher than the mass dissolved in porewaters. significant Se exposure may result from oxidative shifts in Se associations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02406867
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  • 102
    Electronic Resource
    Electronic Resource
    Bottom sediments in a humic lake with artificially increased calcium content: Sink or source for phosphorus? (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 457-464 
    Details
    ISSN: 1573-2932
    Keywords: sediment ; phosphorus ; fractionation ; release ; humic lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Lake Flosek (north-eastern part of Poland) is a small shallow and without outflow lake which has been limed in 1970. The concentration of Ca was increased from 3–4 mg L−1 to 17 mg L−1 in the water and from 0.2–0.3% dry weight to 0.9–1.7% dry weight in sediments (5 cm upper layer) due to CaCO3 addition to the lake. In the spring-summer seasons of 1992 and 1993, an experimental study was conducted in Lake Flosek to assess the capacity of bottom sediments to uptake and release mineral phosphorus. The rate of phosphorus exchange between sediments and near-bottom water was experimentally measured under conditions of high (100%), and of reduced (10%) oxygen saturation in near-bottom water. To determine the component of sediments responsible for the uptake of most phosphorus, the proportions of phosphorus forms in sediments were analysed. Sediments of Lake Flosek showed a slight tendency to release phosphates. The rate of this process was similar under high (100%) and low (10%) oxygen saturations ranging from - 0.161 to + 0.200 mg P m−2 d−1. This is much lower (by 1–2 orders of magnitude) than reported from other harmonic, non-humic lakes. In the total phosphorus pool, the highest content of phosphorus was found in the organic and residual phosphorus fractions (over 70% of the total phosphorus in sediments). The largest part of the readily extractable phosphorus was found in the fraction bound to AI and humic substances (41%). Both these fractions determine a weak exchange of phosphorus between sediments and water. No difference in P-release related to P-fraction compound was found in the cores taken from three sites in the lake.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02406885
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  • 103
    Electronic Resource
    Electronic Resource
    An Assessment of Heavy Metal Pollution in the Sediments Along the Albanian Coast (1999)
    Springer
    Water, air & soil pollution 111 (1999), S. 235-250 
    Details
    ISSN: 1573-2932
    Keywords: atomic absorption spectroscopy ; background level ; heavy metal ; lognormal distribution ; normalization ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract An evaluation is presented of heavy metal pollution, based on statistical analysis of metal concentrations in the sediments from an area along the Albanian Coast. This includes a detailed description of levels of the most important pollutants. Examination of lognormal metal distribution plots indicates that the curve inflections may be operationally used as a threshold between polluted and unpolluted areas. Fe is used for mineralogical normalization of the data. The normalization procedure identifies the most polluted areas. It is clearly demonstrated that some industrial activities such as mining, harbour and chlor-alkali plant, notably affect the heavy metals concentration in the sediments. An evaluation of bakcground levels for the sediments of the Adriatic Albanian coast is also carried out.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005086208998
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  • 104
    Electronic Resource
    Electronic Resource
    Sorption Kinetics and Transformation of DDT in Sediment (1999)
    Springer
    Water, air & soil pollution 110 (1999), S. 57-66 
    Details
    ISSN: 1573-2932
    Keywords: DDT ; kinetic ; organic pollutant ; sediment ; sorption ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The overall objective of this study was to investigate the sorption kinetics of DDT in sediment under similar experimental conditions employed in corresponding toxicity studies for bentic organisms. A batch of aerated Schoonrewoerdse Wiel sediment, initially spiked with DDT, was sampled over a period of seven days. Concentrations of DDT, DDD and DDE were determined in both the solid and the solution phase in the sediment/water system after separation by centrifugation. It was found that the extractable amount of DDT decreased with increasing contact time. This can partly be explained in terms of transformation of DDT into DDD. Furthermore, the present applied extraction procedure seems to be less effective with increasing contact time, indicating an increase in binding strength of DDT with the sediment material. Finally, on the basis of DDT, DDE and DDD concentrations in both the solid phase and the solution phase, partition coefficients were calculated, which appeared to be independent of the contact time. This points at a very rapid equilibrating between DDT in pore water and in the extractable forms adsorbed at the solid phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005087429581
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  • 105
    Electronic Resource
    Electronic Resource
    Metal Pollution by Old Lead-Zinc Mines in Urumea River Valley (Basque Country, Spain). Soil, Biota and Sediment (1998)
    Springer
    Water, air & soil pollution 107 (1998), S. 303-319 
    Details
    ISSN: 1573-2932
    Keywords: base metal mining ; biota ; metal pollution ; sediment ; soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Soil, aquatic biota (moss: Brachythecium rivulare; aquatic macrophytes: Juncus effusus, Potamogeton crispus; fish: Salmo trutta fario, Anguilla anguilla, Phoxinus phoxinus, Chelon labrosus) and sediment samples from the Urumea river valley were analysed for metals by acid digestion and atomic absorption spectroscopy. The sediments show the presence of metal pollution (Cd: 2.5–24 mg kg-1; Pb: 125–1,150 mg kg-1; Zn: 125–2,500 mg kg-1) because mining and industrial wastes. A selective retention of dense minerals in dam sediments contributes to the load of metal, but interstitial water analysis (Cd: 〈0.02–0.1 mg L-1; Pb: 0.3–1.0 mg L-1; Zn: 〈0.05–0.6 mg L-1) shows that precipitation equilibrium controls their mobilisation. Biota samples show evidence of metal accumulation, moss reaching 1,100 mg kg-1 in lead and 6,800 mg kg-1 in zinc. Soil from the valley is polluted by both, river carried material and industrial sources (Cd: 1.0–4.0 mg kg-1; Pb: 26–1,120 mg kg-1; Zn: 105–1,390 mg kg-1/math〉), but they are used, indistinctly, for farming and pasture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004925922786
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  • 106
    Electronic Resource
    Electronic Resource
    Biogeochemistry of Iron and Sulfur in Sediments of an Acidic Mining Lake in Lusatia, Germany (1998)
    Springer
    Water, air & soil pollution 108 (1998), S. 231-247 
    Details
    ISSN: 1573-2932
    Keywords: bacterial sulfate reduction ; iron reduction ; sediment ; pore-water chemistry ; acidic mining lake ; stable sulfur isotopes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Chemical, microbiological and stable isotope analyses of sediments from an acidic mining lake were used to evaluate whether biogeochemical processes, such as iron and sulfate reduction, are extant, because such processes can potentially generate alkalinity. Sediment cores were sliced in cm intervals to achieve a high resolution for spatial distribution of organic and inorganic components. Iron, sulfur, carbon, nitrogen and phosphorus as well as the most probable number (MPN) of iron reducing bacteria, the amount of lipid phosphate and the stable isotope compositions of various sedimentary sulfur compounds were measured. Accumulation of degradable organic material, reduced mass fractions of iron, enhanced concentrations of lipid phosphate, high concentrations of DOC and ferrous iron in the pore water and a drastic change of sulfur isotope ratios in the upper 3 cm of the sediment all indicated a highly reactive zone of biogeochemical transformations. The data provide clear evidence for iron and sulfate reducing processes in the sediments that result in an increase of pH with depth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005195617195
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  • 107
    Electronic Resource
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    Nitrogen and Phosphorus Levels in Sediments from Tropical Catatumbo River (Venezuela) (2000)
    Springer
    Water, air & soil pollution 117 (2000), S. 27-37 
    Details
    ISSN: 1573-2932
    Keywords: eutrophication ; nitrogen ; phosphorus ; river ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Nitrogen (N) and phosphorus (P) concentrations were determined in sediment samples along the bed of Catatumbo river in both Colombian and Venezuelan territories until the river outlet in Maracaibo lake. Total phosphorus was determined by digestion with HCl followed by analysis using the ascorbic acid method and total nitrogen was done using the standard microkjeldahl method plus nitrate-nitrite. Ammonium, orthophosphate and nitrate were determined using standard methods after extraction steps. The mean concentrations along the river bed were found in an interval of 0.035 and 1.492 mg g-1 dry sed. for nitrogen and 0.027 and 1.039 mg g-1 dry sed. for phosphorus at 95% confidence level. The mean molar ratio N/P in the river bed was 4.42 and 3.46 for river outlet zones in the lake, which indicates that nitrogen is the limiting nutrient. For comparison with previous results of lake sediments from sites near the river outlet it was concluded that Catatumbo river is a significant source of nutrients to the Maracaibo Lake system because sediment nutrients concentrations from Catatumbo river were higher than the ones in Maracaibo Lake. Statistic studies showed significant differences between countries, zones and similar behaviour in the river bed as related to the affluent rivers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005189710803
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  • 108
    Electronic Resource
    Electronic Resource
    Trace Metals in Marine Algae and Sediment Samples from the Bosphorus (2000)
    Springer
    Water, air & soil pollution 118 (2000), S. 27-33 
    Details
    ISSN: 1573-2932
    Keywords: algae ; Bosphorus ; sediment ; trace metals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Concentration of As, Cr, Fe, Zn, Co, Sb, Pb, Cd and Cu weredetermined in sediment and algae samples collected from theBosphorus in Turkey. Certain algae species were chosen among thegreen, brown and red algae species at three sampling stations.Element analyses were carried out by atomic absorptionspectrophotometry and instrumental neutron activation analysis. The locations having the highest metal concentrations insediments were as follows: As at Poyraz; Cr, Zn, Sb at RumeliFeneri and Fe, Co at Garipçe. In genral, the accumulation ofmost of the metals showed no direct correlation with algaespecies. On the other hand, C. verticillatus and C. barbataspecies of brown algae showed ability to accumulate arsenic.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005149500870
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  • 109
    Electronic Resource
    Electronic Resource
    Runoff and Sediment Attenuation by Undisturbed and Lightly Disturbed Forest Buffers (2000)
    Springer
    Water, air & soil pollution 122 (2000), S. 121-138 
    Details
    ISSN: 1573-2932
    Keywords: Soil erosion ; sediment ; water pollution ; forestry ; logging ; buffer strips
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A runoff plot experiment found that ten metre undisturbed forest buffers removed80–90% of runoff and over 95% of sediment produced by logging skid tracks. The study was carried out on 21º slopes in a native forest in eastern New South Wales, Australia. The experiment included three replicates of four treatments including undisturbed control, skid track, skid track + undisturbed buffer and skid track + disturbed buffer. Skid track and control plots were 20 m long by 5 m wide. Buffer plots consisted of a 20 m by 5 m skid track directing runoff to a 10 m by 5 m naturally vegetated buffer that was either undisturbed or lightly disturbed. Runoff and sediment yields from plots were monitored over two successive summers. Undisturbed buffers greatly reduced overland flow and decreased sediment yields from around 100 Mg ha1 to less than 0.5 Mg ha-1. Differences in both runoff and sediment yield between undisturbed buffer and control treatments were minimal and not statistically significant. Disturbed buffers achieved similarly large reductions in runoff and sediment yield in two out of three replicates. The third replicate yielded as much or more runoff and sediment than the skid track plots suggesting that disturbance increased the risk of buffer failure. The peak rate of outflow from buffer plots was generally not related to peak buffer inflow until a threshold inflow of 1.6 L s-1 was reached, after which peak outflow and peak inflow were linearly related.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005283403178
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  • 110
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    Speciation of As(III) and As(V) in some Ghanaian Gold Tailings by a Simple Distillation Method (2000)
    Springer
    Water, air & soil pollution 122 (2000), S. 317-326 
    Details
    ISSN: 1573-2932
    Keywords: arsenic ; distillation ; gold tailing ; neutron activation analysis ; sediment ; speciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract As(III) and As(V) in goldtailings and river-bedsediments from Obuasi were determined by distillationof arsenic as AsCl3. Results yielded 3750±426 mg kg-1 (45.2%) for As(V) and 3050±66 mg kg-1 (36.7%) for As(III) in the tailings. In the river-bed sediments, one spot yielded: As(III) 0 mg kg-1 (0%) and As(V) 1447±51 mg kg-1 (100%), whilst a second spot yielded: As(III) 0 mg kg-1 (0%) and As(V) 2976±51 mg kg-1 (100%). Using arsenic oxide standards, the recovery of As(III) and As(V) in the trioxide were 94.8 and 0.6% respectively. In a mixture of the two oxides, the recovery of As(III) was 87.6% with practically no interference from As(V). Total As content of the tailings was determined by neutron activation analysis (NAA) to be 8305±75 mg kg-1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005286832435
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  • 111
    Electronic Resource
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    Heavy Metal Concentration in Surficial Sediments from Anzali Wetland, Iran (1998)
    Springer
    Water, air & soil pollution 104 (1998), S. 305-312 
    Details
    ISSN: 1573-2932
    Keywords: heavy metals ; sediment ; analysis ; Anzali wetland ; Iran
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Concentrations of Cd, Pb, Cu, Zn and Ni were determined in surficial sediments from eleven sampling sites in Anzali wetland. Four different methods were tested to choose the most efficient procedure for determination of the metals. The measurement of the metal levels were performed using atomic absorption spectroscopy. In order to interpret analytical results, several statistical methods were applied. There were statistically significant differences among the accumulation of the metals in sediments, while differences were not be observed among the seasons. Sampling site eight showed the lowest similarity compared to others. Kurtzfassung. Gehalte an Cd, Pb, Cu, Zn und Ni wurden in den oberflächliche sedimenten von elf probestellen aus der Anzali Lagune gemessen. Vier verschiedene Methoden Wurden untersucht um das leistungsfähigste zu wählen. Die Messungen wurden mittles flammen-AAS vorgenommen. Zur Interpretation der Ergebnisse, mehrere statistische Methoden wurden angewendet. Es gab allgemein statistische Signifikanz Unterschiede zwischen der Akkumulation der Metalle in Sedimente. Beträchtliche Unterschiede zwischen den Jahrezeiten Konnten dagegen nicht festgestellt werden. Die Probestelle acht wies die geringste Ähnlichkeit mit den anderen auf.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004975925275
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  • 112
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    A Critical Evaluation of Sample Pretreatment for Storage of Contaminated Sediments to be Investigated for the Potential Mobility of their Heavy Metal Load (1998)
    Springer
    Water, air & soil pollution 103 (1998), S. 137-149 
    Details
    ISSN: 1573-2932
    Keywords: heavy metals ; pretreatment ; sediment ; speciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The identification of the geochemical forms of heavy metals in contaminated sediments gives information on their availability. This requires the use of a geochemical speciation procedure such as the one developed by Tessier et al. (1979). In addition to the imperfections of these protocols, their results can vary depending on the technique used for the preservation of sediments which must be suited to the materials studied and to particularities of the investigation. This study was carried out on superficial river sediments, seriously polluted by Cu, Cd and Pb. Compared to fresh sediment, none of the drying methods studied (freeze-drying, air-drying and oven-drying at 105 °C) completely preserve the distribution of Cu, Pb, Zn and Cd in the various geochemical fractions of the sediment. The modifications depend directly on the quantities of metals present in the various fractions of the sediment, the effects being more marked when the quantity is smallest. This results in a decrease in metals in the exchangeable fraction and in those bound to carbonates under the action of atmospheric oxygen and a corresponding increase in the other fractions. To minimize this, freeze-drying and air-drying are satisfactory techniques which enable preservation of sediments representative of the environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004952608950
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  • 113
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    Influence of Physical and Chemical Characteristics on Mercury in Aquatic Sediments (1999)
    Springer
    Water, air & soil pollution 110 (1999), S. 347-362 
    Details
    ISSN: 1573-2932
    Keywords: lakes ; methyl mercury ; Newfoundland ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Given the variation observed in mercury in fish from natural lakes, it is difficult to determine what represents a background mercury level. Mercury in aquatic sediments is a potential source of this trace metal to biota, notably fish. Site specific factors, such as acidity and dissolved organic carbon have been shown to affect the mobilization of mercury and methylation of mercury. Methyl mercury is the most toxic form of this metal and the form most readily accumulated by biota. Thirty-four headwater lakes, selected for a range in pH, were sampled for sediment mercury levels as part of an investigation of the impacts of acid rain on insular Newfoundland lakes. Selected physical and chemical data were also collected on all of the study sites. Acidity was not found to be significantly related to sediment mercury concentrations despite the wide range in pH. Pearson correlation analysis indicated that sediment mercury level was positively correlated with WA:LA (watershed to lake area ratio). WA:LA was also correlated with Secchi depth and colour. Linear regression was used to estimate the parameters of a model relating sediment mercury to WA:LA. Watershed area to lake area ratio was more important than site specific factors in governing the concentration of sediment mercury in lakes without industrial input.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005007402287
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  • 114
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    Mobilisation of Heavy Metals in Contaminated Sediments in the River Meuse, The Netherlands (1999)
    Springer
    Water, air & soil pollution 116 (1999), S. 567-586 
    Details
    ISSN: 1573-2932
    Keywords: Complexation ; diffusion ; heavymetals ; mobilisation ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Due to seasonal variation in bottom-water temperature and degradation of organic matter, the depths of the redox boundaries fluctuate in sediments of the river Meuse. This is reflected by a non-steady state behaviour of heavy metals in the surface sediments. Levels of acid-volatile sulphides suggest that dissolved concentrations of heavy metals in the anoxic pore waters are determined by their respective sulphide phases. However, complexation with dissolved organic ligands may significantly increase dissolved concentrations of heavy metals. In most sediments studied, a distinct peak in dissolved concentrations of heavy metals is measured immediately below the sediment-water interface. This concentration peak may be attributed to degradation of organic matter and oxidation of sulphides. Dissolved concentration gradients indicate that upward diffusion of heavy metals from the sediment can contribute to concentrations in the surface water, although significant effects may be confined to specific locations. In addition, it is shown that release of heavy metals as dissolved species to the surface water is negligible compared to particulate-bound fluxes of heavy metals to the sediment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005146927718
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  • 115
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    Speciation and Concentrations of Mercury in Certain Coastal Marine Sediments (1998)
    Springer
    Water, air & soil pollution 103 (1998), S. 129-136 
    Details
    ISSN: 1573-2932
    Keywords: coastal pollution ; mercury ; methylation ; methyl mercury ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Concentrations of total mercury (Hg), methyl Hg and Hg(II) were determined in coastal marine sediments collected from the Baltic, South China and the Bering Seas. Methyl Hg concentrations in sediments were between 0.01 and 2 ng g-1 on a dry weight basis, accounting for only 〈1% of the total Hg concentrations. The percentage of Hg(II) (i.e. available Hg) in total Hg was between 5 and 13 suggesting that most of the Hg in sediments was bound as HgS and/or Hg-humic complexes. Relatively larger proportion of methyl Hg was found in less polluted freshwater sediments than in marine sediments. Methyl Hg concentrations in marine sediments were not found to be correlated with total Hg and/or Hg (II) concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004967112178
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  • 116
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    Influence of Sediment Preservation on Total Mercury and Methylmercury Analyses (1998)
    Springer
    Water, air & soil pollution 107 (1998), S. 277-288 
    Details
    ISSN: 1573-2932
    Keywords: freezing ; lyophilisation ; mercury ; methylmercury ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Estuarine and riverine sediments from fourlocations showing different sediment structures wereanalysed as fresh, thawed and lyophilised samples fortotal mercury (TotHg) and methylmercury (MeHg)concentrations, and results were compared to addresseffects of sample preservation on Hg speciation. TotHg was measured by cold vapour atomic absorptionspectrometry (CVAAS). MeHg was isolated bydistillation and ion-exchange and analysed by coldvapour atomic fluorescence spectrometry (CVAFS) afterpreconcentration on a gold trap. No loss of TotHg norMeHg due to lyophilisation was found. Concentrationsof TotHg and MeHg respectively ranged from 92 to 267ng g-1 dw and 1.1 to 2.9 ng g-1 dw in freshsamples, from 94 to 215 ng g-1 dw and 1.1 to 2.8ng g-1 dw in thawed samples, and from 100 to 256ng g-1 dw and 1.2 to 3.1 ng g-1 dw inlyophilised samples. Lyophilised samples showedbetter homogeneity and better MeHg analysisreproducibility compared with wet samples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019886606856
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  • 117
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    Phosphorus Retention Mechanisms in the Sediment of an Eutrophic Mining Lake (1998)
    Springer
    Water, air & soil pollution 108 (1998), S. 341-352 
    Details
    ISSN: 1573-2932
    Keywords: mining lake ; sediment ; phosphorus release ; phosphorus fractionation ; eutrophication ; phosphorus retention
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A small, highly eutrophic mining lake (Golpa IV) in eastern Germany with a continuous input of nutrients and metals was used to study the mechanisms of phosphorus (P) fixation in the sediment. The sediment (0-15 cm) is characterised by high contents of iron (96 mg g-1 DW), aluminium (37.3 mg g-1 DW) and sulphur (54.3 mg g-1 DW) and an extreme accumulation of some trace metals. Despite oxygen free conditions in the hypolimnion and intensive sulphate reduction in the sediment, high P retention rates could be calculated from dated sediment cores (1986-1995: 11 g P m-2 a-1). The lake has shown a rapid response to reduction of P loading. In some sediment layers unusually high total sediment P concentrations with more than 24 mg P g-1 DW were observed. More than 80% of total sediment P was bound in the BD-SRP and NaOH-SRP fractions (extraction scheme according to Psenner et al., 1984) which indicates that a substantial portion of deposited P is immobilised in an Fe or Al bound form. This corresponds well with the presence of oxidised Fe species at all sediment depths. Furthermore thermodynamic calculations indicate that vivianite precipitation is favourable in deeper anoxic sediment layers. The inventory or input of Fe or Al seems to be more important for the permanent P immobilisation in the sediment of the investigated mining lake than redox forced mobilisation processes (e.g. iron or sulphate reduction).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005130002600
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  • 118
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    Methyl Mercury Production and Distribution in River Water-Sediment Systems Investigated Through Radiochemical Techniques (2000)
    Springer
    Water, air & soil pollution 124 (2000), S. 113-124 
    Details
    ISSN: 1573-2932
    Keywords: bioturbation ; freshwater systems ; methylation ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The toxicological consequences of Hg releases to the environment are largely governed by the conversion ofinorganic Hg to the most toxic methylmercury (MeHg), that is biomagnified through aquatic food chains. To gain further insight on the biological and physico-chemical factors controlling MeHg production and distribution among freshwater sediments and water, we used a sensitive and specific radiochemical procedure, developed at the National Institute for Minamata Disease. Systems containing 203Hg2+-spiked sediment cores (0.7 μg total Hg g-1 d.w.) and overlying water, both from a pristine mountain stream in Southern Japan, were incubated for 21–38 days in different conditions. Inorganic Hg and MeHg in sediment and water were extracted in dithizone-benzene and measured after separation by thin-layer chromatography. The conversion of added Hg to MeHg was 3.0 to 13.7% in sediments, with a tendency for higher proportions in the top layers. Surprisingly, more MeHg was found in the sediment (11.3%) and water (66.5%) of a system bubbled with air than in one bubbled with nitrogen (4.2 and 44.1%). Artificially increased levels ofbioturbation reduced by half the MeHg concentrationsand % of added total Hg in sediment and water. In allsystems, 55–68% of total Hg and MeHg in water wereassociated to suspended particles 〉1μm. MeHgbioaccumulation factors (BFs) from water ranged270–8100 and from sediment, 0.2–5.7 (wet weight basis). BFs in relation to water where 3 times higher for MeHg than for total Hg.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005206109083
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