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Lars-Göran Danielsson Bertil Magnusson Stig Westerlund Kerong Zhang 《Estuarine, Coastal and Shelf Science》1983,17(1):73-85
The concentrations of the trace metals Cd, Cu, Fe, Ni, Pb and Zn in the Göta River estuary have been investigated. The following metal fractions have been determined: acid-leachable, dissolved, labile and particulate.The estuary represents a salt wedge type estuary and is situated in a densely populated region of Sweden. The metal concentrations found for the dissolved fraction is in the range of what can be considered as background levels for freshwater. It is difficult to evaluate any estuarine processes other than conservative mixing for Cd, Cu, Ni and Zn. The dissolved levels in the freshwater end member are Cd, 9–25 ngl?1; Cu, 1·1–1·4 μgl?1; Fe, 20–75 μg l?1: Ni, 0·7–0·9 μg l?1: Pb 0·09–0·2 μg l?1; and Zn, 6–7 μg l?1:The results from the acid-leachable fraction show that at high suspended load the particles sediment in the river mouth. The trace metal levels in this fraction are subject to large variations. 相似文献
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Lars-Göran Danielsson David Dyrssen Anders Granéli 《Geochimica et cosmochimica acta》1980,44(12):2051-2065
Analytical data for the Atlantis II and Discovery deeps in the Red Sea are given. The data were collected in March and June 1976 during the 22nd cruise of R/V Akademik Kurchatov in the Indian Ocean. On board analyses were performed of density, chlorinity, Mg, Ca, Sr and trace elements. The salinity, calculated from the density, is related to the chlorinity by S = 1.67 Cl + 4.02. The Ca-salinity relation is linear for both deeps showing that intermediate waters are formed by mixing of the brines with Red Sea water (RSDW). The hot brine (62°C) in the Atlantis II deep contains approx. 80 mg/kg of Fe and Mn while the warm brine (45°C) in the Discovery deep has a very low concentration of Fe and approx. 50 mg/kg of Mn. Mixing of RSDW containing 2 ml/l of oxygen with the anoxic deep brines causes precipitation of hydrous Mn(IV) and Fe(III) hydroxides. These two processes occur at different depths in the two deeps due to the formation of the warm (48–49°) intermediate brine in the Atlantis II deep. The oxidation-hydrolysis reactions proposed are supported by alkalinity-depth profiles and measurements of pH. These reactions also explain most of the trace element distributions and the composition of the SiO2-Fe(III) hydroxide slurry recovered by some water samplers in the Atlantis II deep. 相似文献
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Lars-Göran Danielsson 《Marine Chemistry》1980,8(3):199-215
Results of trace-metal analyses of water samples obtained during a cruise with the Soviet R.V. “Akademik Kurchatov” in the Indian Ocean are presented. The determinations were performed on board with atomic absorption spectrophotometry after a two-stage dithiocarbamate—Freon extraction procedure. Trace-metal concentrations found are in the same range as those found recently for similar open-ocean areas by other workers. The values for lead and zinc are probably high due to contamination. Vertical profiles indicate biogenic processes as controlling factors for the increase of cadmium, copper and nickel concentrations with depth. Iron shows an irregular depth distribution as a result of large random variations in concentration. 相似文献
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Baltic surface water was sampled at a fixed position at intervals of a few hours. The trace metal concentrations were measured by graphite furnace AAS after extraction. The mean concentrations found were (ng l?1): Cd, 30 ± 2.7; Cu, 800 ± 48; Fe, 358 ± 165; Ni, 820 ± 49; Pb, 16 ± 4.5; Zn, 900 ± 160. The variability in the trace metal concentrations is of the same order of magnitude as the precision of the method. Thus, no spatial variations in trace metal concentrations were found. 相似文献
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Lutz Brügmann Lars-Göran Danielsson Bertil Magnusson Stig Westerlund 《Marine Chemistry》1985,16(1):47-60
Lead has been determined in 105 water samples from the north east Atlantic and from the North Sea. Rigorous precautions were applied to avoid contamination during sampling and analysis.Two different analytical methods were used: ASV and AAS. Determinations with ASV were carried out on board, directly after sampling. After two months storage, acidified samples were analysed by AAS after freon dithiocarbamate extraction and nitric acid back extraction. Particulate lead was determined by AAS after an acid digestion.The profiles of lead concentration versus depth show around 160 pM at the surface and around 20 pM at the bottom, both in the Atlantic and in the Norwegian Sea. The shapes of the profiles are different, however, depending on the hydrography of the area sampled. The profiles from the north east Atlantic coincide with a recently published profile from the north west Atlantic. Moreover, these profiles have lead concentrations about a factor of three higher than those in the Pacific.Considering the high lead input to the North Sea, the lead concentrations found there are remarkably low, probably because of scavenging effects in estuaries leading to a short residence time in the water column. The dominant lead input in offshore regions is from the atmosphere. The highest lead levels are found in the northern North Sea, around 300 pM in surface water.In the Atlantic, particulate lead is a minor part of the total lead whereas in the North Sea the particulate fraction is larger, up to 40%. 相似文献
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Emma Bosson Jan-Olof Selroos Martin Stigsson Lars-Göran Gustafsson Georgia Destouni 《Hydrogeology Journal》2013,21(1):225-237
This study simulates and quantifies the exchange and the pathways of deep and shallow groundwater flow and solute transport under different climate and permafrost conditions, considering the example field case of the coastal Forsmark catchment in Sweden. A number of simulation scenarios for different climate and permafrost condition combinations have been performed with the three-dimensional groundwater flow and transport model MIKE SHE. Results show generally decreasing vertical groundwater flow with depth, and smaller vertical flow under permafrost conditions than under unfrozen conditions. Also the overall pattern of both the vertical and the horizontal groundwater flow, and the water exchange between the deep and shallow groundwater systems, change dramatically in the presence of permafrost relative to unfrozen conditions. However, although the vertical groundwater flow decreases significantly in the presence of permafrost, there is still an exchange of water between the unfrozen groundwater system below the permafrost and the shallow groundwater in the active layer, via taliks. ‘Through taliks’ tend to prevail in areas that constitute groundwater discharge zones under unfrozen conditions, which then mostly shift to net recharge zones (through taliks with net downward flow) under permafrost conditions. 相似文献
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