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1.
In this paper, size‐exclusion chromatography (SEC) was used to determine the metal concentration in different size fractions of a bog lake water. Two methods were applied: (a) preparative SEC with off‐line metal concentration analysis and (b) direct coupling of an analytical SEC system on‐line with an inductively‐coupled plasma mass spectrometer (ICP‐MS). In the preparative SEC measurements, maximum concentrations were found for different metal ions in different size fractions of the natural organic matter (NOM). Normalization of metal concentrations to dissolved organic carbon concentration (DOC) yielded two maxima in the high and in the very low molecular‐weight fractions. Whereas good recoveries were found for Al, Fe, and Ni, only 40% were obtained for Pb. This indicates that Pb formed labile complexes with NOM, and hence could strongly interact with the column material. In the experiments with the analytical SEC‐ICP‐MS system, the same trends were observed, but with even lower recoveries than in the preparative system. Sample preconcentration and storage were also investigated with respect to decrease in metal concentration. During the ultrafiltration preconcentration step Al and Fe were removed only to a small extent, whereas about half of the initial Pb was lost. This indicates that Al and Fe were mainly bound to high molecular‐weight fractions of NOM. In contrast to that, Al and in particular Fe were removed from solution more than proportionally with respect to DOC because of aggregation of the NOM during storage, whereas Pb and Ni were concentrated relative to the DOC.  相似文献   

2.
Phytoremediation, a plant‐based and cost‐effective technology for the cleanup of contaminated soil and water, is receiving increasing attention. In this study, the aquatic macrophyte Eleocharis acicularis was examined for its ability to take up multiple heavy metals and its potential application for phytoremediation at an abandoned mining area in Hokkaido, Japan. Elemental concentrations were measured in samples of E. acicularis, water, and soil collected from areas of mine tailing and drainage. The results reveal that Pb, Fe, Cr, Cu, Ni, and Mn accumulation in the plants increased over the course of the experiment, exceeding their initial concentrations by factors of 930, 430, 60, 25, 10, and 6, respectively. The highest concentrations of Fe, Pb, Zn, Mn, Cr, Cu, and Ni within the plants were 59500, 1120, 964, 388, 265, 235, and 47.4 mg/kg dry wt., respectively, for plants growing in mine drainage after 11 months of the experiment. These results indicate that E. acicularis is a hyperaccumulator of Pb. We also found high Si concentrations in E. acicularis (2.08%). It is likely that heavy metals exist in opal‐A within cells of the plant. The bioconcentration factors (BCF: ratio of metal concentration in the plant shoots to that in the soil) obtained for Cr, Cu, Zn, Ni, Mn, and Pb were 3.27, 1.65, 1.29, 1.26, 1.11, and 0.82, respectively. The existence of heavy metals as sulphides is thought to have restricted the metal‐uptake efficiency of E. acicularis at the mine site. The results of this study indicate that E. acicularis shows great potential in the phytoremediation of mine tailing and drainage rich in heavy metals.  相似文献   

3.
Frequent heavy rainfalls during the East Asian summer monsoon drastically increase water flow and chemical loadings to surface waters. A solid understanding of hydroclimatic controls on watershed biogeochemical processes is crucial for water quality control during the monsoon period. We investigated spatio‐temporal variations in the concentrations and spectroscopic properties of dissolved organic matter (DOM) and the concentrations of trace metals in Hwangryong River, Korea, during a summer period from the relatively dry month of June through the following months with heavy rainfall. DOM and its spectroscopic properties differed spatially along the river, and also depended on storm and flow characteristics around each sampling time. At a headwater stream draining a forested watershed, the concentrations (measured as dissolved organic carbon (DOC)), aromaticity (measured as specific UV absorbance at 254 nm), and fulvic acid‐ and protein‐like fluorescence of DOM were higher in stormflow than in baseflow waters. DOC concentrations and fluorescence intensities increased along the downstream rural and urban sites, in which DOC and fluorescence were not higher in stormflow waters, except for the ‘first flush’ at the urban site. The response of DOM in reservoir waters to monsoon rainfalls differed from that of stream and river waters, as illustrated by storm‐induced increases in DOM aromaticity and fulvic‐like fluorescence, and no significant changes in protein‐like fluorescence. The results suggest that surface water DOM and its spectroscopic properties differentially respond to changes in hydroclimatic conditions, depending on watershed characteristics and the influence of anthropogenic organic matter loadings. DOC concentrations and intensities of spectroscopic parameters were positively correlated with some of the measured trace metals (As, Co, and Fe). Further research will be needed to obtain a better understanding of climate effects on the interaction between DOM and trace metals. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

4.
The effect of land reclamation on the migration and accumulation of heavy metals and some pollutants in small rivers is determined. The study was conducted in the Middle Amur lowland in different phases of hydrological regime and at different extent of floodplain inundation. The formation of the hydrological regime in small rivers in this area is governed by the irregular annual runoff distribution. The seasonal character of flood periods requires water samples to be taken before spring flood (April) and after floods have passed (September–October), and at various extent of floodplain inundation. The field studies of water-courses were carried out in 2009–2014. The water samples were analyzed to determine the concentrations of heavy metals (iron, manganese, copper, nickel, cobalt, lead and zinc), suspended substances, organic carbon (total, dissolved, and suspended), humic and fulvic acids, and volatile organic compounds. The mobility of heavy metals in surface watercourses was shown to reflect the effect of drainage and surface runoff from soil horizons, an increase in the concentrations of suspended and organic compounds, especially, fulvic acids, which enhance their geochemical mobility. During floods, an increase in heavy metals washout from floodplain soils and the dilution of their concentrations causes the formation of a single-type concentration series of heavy metals. In addition, the processes of pollutants migration show an effect of changes in the geomorphological characteristics of floodplain–channel complexes and a decrease in flow velocity in watercourses in the areas where land reclamation was applied. Thus, all factors mentioned above lead to a decrease in water pollution index in the river.  相似文献   

5.
Dissolved Zn, Cu and Cd concentrations in interstitial waters collected from a lacustrine mine tailings deposit indicate that the tailings are not releasing heavy metals to the overlying lake water at present, and there is no evidence to suggest that significant oxidation is occurring in the deposit. The lake waters are enriched in metals from surface drainage, however, while pore waters in natural sediments are heavy-metal-depleted. Diffusion into the natural sediments therefore tends to buffer the lacustrine metal load, but only to a very limited extent.  相似文献   

6.
The X-ray fluorescence analysis is an important means for the determination of the heavy metal concentrations in sewage sludges and for the evaluation of their usability in agriculture. Analysis devices from the GDR were used for that. For the investigations there was used as the zero sample a sludge which was not loaded with heavy metals, homogeneous and constantly dried at 105 °C. The drying bed sludge samples were treated with different heavy metal solutions with different concentrations. Preparation of samples, measuring conditions and general spectra are described. The measuring results of tests up to 100 g heavy metal in 1 kg dry substance are critically evaluated. The analysis of a sewer sludge sample takes only about ten minutes. There are determined: Cr, Ni, Cu, Zn, Mo, Cd, Hg and Pb.  相似文献   

7.
Amount and composition of dissolved organic matter (DOM) were evaluated for multiple, nested stream locations in a forested watershed to investigate the role of hydrologic flow paths, wetlands and drainage scale. Sampling was performed over a 4‐year period (2008–2011) for five locations with drainage areas of 0.62, 3.5, 4.5, 12 and 79 ha. Hydrologic flow paths were characterized using an end‐member mixing model. DOM composition was determined using a suite of spectrofluorometric indices and a site‐specific parallel factor analysis model. Dissolved organic carbon (DOC), humic‐like DOM and fluorescence index were most sensitive to changes with drainage scale, whereas dissolved organic nitrogen, specific UV absorbance, Sr and protein‐like DOM were least sensitive. DOM concentrations and humic‐like DOM constituents were highest during both baseflow and stormflow for a 3.5‐ha catchment with a wetland near the catchment outlet. Whereas storm‐event concentrations of DOC and humic DOM constituents declined, the mass exports of DOC increased with increasing catchment scale. A pronounced dilution in storm‐event DOC concentration was observed at peak stream discharge for the 12‐ha drainage location, which was not as apparent at the 79‐ha scale, suggesting key differences in supply and transport of DOM. Our observations indicate that hydrologic flow paths, especially during storms, and the location and extent of wetlands in the catchment are key determinants of DOM concentration and composition. This study furthers our understanding of changes in DOM with drainage scale and the controls on DOM in headwater, forested catchments. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

8.
We investigated the effects of ditch blocking on fluvial carbon concentrations and fluxes at a 5‐year, replicated, control‐intervention field experiment on a blanket peatland in North Wales, UK. The site was hydrologically instrumented, and run‐off via open and blocked ditches was analysed for dissolved organic carbon (DOC), particulate organic carbon, dissolved carbon dioxide, and dissolved methane. DOC was also analysed in peat porewater and overland flow. The hillslope experiment was embedded within a paired control‐intervention catchment study, with 3 years of preblocking and 6 years of postblocking data. Results from the hillslope showed large reductions in discharge via blocked ditches, with water partly redirected into hillslope surface and subsurface flows, and partly into remaining open ditches. We observed no impacts of ditch blocking on DOC, particulate organic carbon, dissolved carbon dioxide or methane in ditch waters, DOC in porewaters or overland flow, or stream water DOC at the paired catchment scale. Similar DOC concentrations in ditch water, overland flow, and porewater suggest that diverting flow from the ditch network to surface or subsurface flow had a limited impact on concentrations or fluxes of DOC entering the stream network. The subdued response of fluvial carbon to ditch blocking in our study may be attributable to the relatively low susceptibility of blanket peatlands to drainage, or to physical alterations of the peat since drainage. We conclude that ditch blocking cannot be always be expected to deliver reductions in fluvial carbon loss, or improvements in the quality of drinking water supplies.  相似文献   

9.
An assessment of metal contamination in surface sediments of the Jiaozhou Bay, Qingdao, one of the rapidly developing coastal economic zones in China, is provided. Sediments were collected from 10 stations and a total of 15 heavy metals were analyzed. Concentrations of metals show significant variability and range from 210 to 620 ppm for Ti, 2.7 to 23 ppm for Ni, 4.2 to 28 ppm for Cu, 5.2 to 18 ppm for Pb, 12 to 58 ppm for Zn, 0.03 to 0.11 ppm for Cd, 5 to 51 ppm for Cr, 1.5 to 9.9 ppm for Co, 5.3 to 19 ppm for As, 12 to 32 ppm for Se, and 19 to 97 ppm for Sr. Based on concentration relationships and enrichment factor (EF) analyses, the results indicate that sediment grain size and organic matter played important roles in controlling the distribution of the heavy metals in surface sediments of the Jiaozhou Bay. The study shows that the sediment of the Jiaozhou Bay has been contaminated by heavy metals to various degrees, with prominent arsenic contributing the most to the contamination. The analysis suggests that the major sources of metal contamination in the Jiaozhou Bay are land‐based anthropogenic ones, such as discharge of industrial waste water and municipal sewage and run‐off. Notably, the elevated heavy metal concentrations of the Jiaozhou Bay sediments could have a significant impact on the bay's ecosystem. With the rapid economic development and urbanization around the Jiaozhou Bay, coastal management and pollution control should focus on these contaminant sources, as well as provide ongoing monitoring studies of heavy metal contamination within the bay.  相似文献   

10.
The production of biosolids in three Spanish wastewater treatment plants (WWTPs) has been investigated. Biosolids produced from the treatment of urban wastewater in Spain are usually intended for agricultural use. The reliable production of biosolids mainly depends on both the quantity of suspended solids and the organic load influent to the treatment systems. The quality of the generated biosolids was independent of both the amount of treated water and the treatment process applied, with 20 to 25% dried matter, and 60 to 75%, 7% and 4% of organic matter, N and P, respectively, of the total matter. The biosolids contained ca. 11 to 19 g/kg of total metals in the dry matter, with Fe, Zn, Cu and Mn representing 97% of all of the metals present, and Hg being the minority metal. Such biosolids had the ability to concentrate the organic matter and metals from the wastewater up to 417 and 869 times, respectively, and thus, can be used in agricultural practice.  相似文献   

11.
The distribution of trace metals in alluvial sediments depends on their natural background concentrations, and on the dynamics of contemporary depositional and erosional (mainly flood‐induced) processes. Geological and geochemical investigations were carried out in the valley of Vistula River near Magnuszew (central Poland). Sediment samples were collected from a depth of 35 cm and comprise sediments of all defined geomorphological features. Identification and geological interpretation of the morphodynamic sediment features was supported by aerial photographs and high‐resolution satellite images. These studies revealed that the distribution of trace metals is closely linked to the morphogenesis of the alluvial floodplain. The highest concentrations of Cu, Co, Zn, V, Cr and Ni were observed in crevasse‐splays deposits. By contrast, Sr, Pb and As were concentrated in deposits which fill oxbow lakes (partly infilled with organic deposits). The lowest concentrations of trace metals were detected in flood sediments deposited within erosional troughs. The geomorphological and sedimentological history of the fluvial features explains the pattern of heavy metal distribution on the current floodplain surface. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

12.
A suite of 36 surface sediment samples, taken between 10 and 100 m water depth in Mejillones Bay (Northern Chile), were analyzed for mineralogy, grain size, total organic carbon, Al, and heavy metal content (Cd, Zn, Ni, Mn, V, Mo). Quartz and feldspars were the main lithogenic minerals and carbonate the predominant biogenic mineral. Sediments were fine sands in the shallow zone and organic silt in the deeper zone.

Enrichment Factor and Factor Analysis approach showed that the presence of Mn in the marine sediment of Mejillones is due to a partial influence of continental input, while all other metals are not supported by lithogenic debris. Although all metals showed high concentrations in the marine sediment of Mejillones Bay, comparison between metal concentration in surface sediments and preindustrial levels in this bay, show that present values agree with natural levels.  相似文献   


13.
A suite of 36 surface sediment samples, taken between 10 and 100 m water depth in Mejillones Bay (Northern Chile), were analyzed for mineralogy, grain size, total organic carbon, Al, and heavy metal content (Cd, Zn, Ni, Mn, V, Mo). Quartz and feldspars were the main lithogenic minerals and carbonate the predominant biogenic mineral. Sediments were fine sands in the shallow zone and organic silt in the deeper zone. Enrichment Factor and Factor Analysis approach showed that the presence of Mn in the marine sediment of Mejillones is due to a partial influence of continental input, while all other metals are not supported by lithogenic debris. Although all metals showed high concentrations in the marine sediment of Mejillones Bay, comparison between metal concentration in surface sediments and preindustrial levels in this bay, show that present values agree with natural levels.  相似文献   

14.
Phytoremediation is an environmental remediation technique that takes advantage of plant physiology and metabolism. The unique property of heavy metal hyperaccumulation by the macrophyte Eleocharis acicularis is of great significance in the phytoremediation of water and sediments contaminated by heavy metals at mine sites. In this study, a field cultivation experiment was performed to examine the applicability of E. acicularis to the remediation of water contaminated by heavy metals. The highest concentrations of heavy metals in the shoots of E. acicularis were 20 200 mg Cu/kg, 14 200 mg Zn/kg, 1740 mg As/kg, 894 mg Pb/kg, and 239 mg Cd/kg. The concentrations of Cu, Zn, As, Cd, and Pb in the shoots correlate with their concentrations in the soil in a log‐linear fashion. The bioconcentration factor for these elements decreases log‐linearly with increasing concentration in the soil. The results indicate the ability of E. acicularis to hyperaccumulate Cu, Zn, As, and Cd under natural conditions, making it a good candidate species for the phytoremediation of water contaminated by heavy metals.  相似文献   

15.
A Full-Scale Porous Reactive Wall for Prevention of Acid Mine Drainage   总被引：3，自引：0，他引：3  
The generation and release of acidic drainage containing high concentrations of dissolved metals from decommissioned mine wastes is an environmental problem of international scale. A potential solution to many acid drainage problems is the installation of permeable reactive walls into aquifers affected by drainage water derived from mine waste materials. A permeable reactive wall installed into an aquifer impacted by low-quality mine drainage waters was installed in August 1995 at the Nickel Rim mine site near Sudbury, Ontario. The reactive mixture, containing organic matter, was designed to promote bacterially mediated sulfate reduction and subsequent metal sulfide precipitation. The reactive wall is installed to an average depth of 12 feet (3.6 m) and is 49 feet (15 m) long perpendicular to ground water flow. The wall thickness (flow path length) is 13 feet (4 m). Initial results, collected nine months after installation, indicate that sulfate reduction and metal sulfide precipitation is occurring. Comparing water entering the wall to treated water exiting the wall, sulfate concentrations decrease from 2400 to 4600 mg/L to 200 to 3600 mg/L; Fe concentrations decrease from 250 to 1300 mg/L to 1.0 to 40 mg/L; pH increases from 5.8 to 7.0; and alkalinity (as CaCO3) increases from 0 to 50 mg/L to 600 to 2000 mg/L. The reactive wall has effectively removed the capacity of the ground water to generate acidity on discharge to the surface. Calculations based on comparison to previously run laboratory column experiments indicate that the reactive wall has potential to remain effective for at least 15 years.  相似文献   

16.
The blocking of drainage ditches in peat has been proposed as a possible mitigation strategy for the widely observed increases in dissolved organic carbon (DOC) concentrations from northern peatlands. This study tested the hypothesis that drain‐blocking could lead to lower DOC concentrations by measuring the DOC export from a series of small peat‐covered catchments over a period of 2 years. Six catchments were chosen: two were pristine that had never been drained; three where drains had been blocked (one in 1995, and two in 2003); and a control peat drain catchment where the drain was left unblocked throughout the study. In the case where drains were blocked as part of thus study, the drains were observed for 2 months before blocking and 2 years after blocking. The results show that: (i) high concentrations of DOC can come from water ponded in the drain; (ii) the DOC export (flux of DOC per area of catchment) from the six study catchments shows a high degree of positive correlation with both catchment size and water yield; (iii) distinctly lower DOC export with water yield was observed for the catchments containing higher‐order channels (>27 500 m2) as opposed to single drain catchments (>7500 m2); (iv) drain‐blocking resulted in a statistically significant decrease in DOC export (average was 39%) but the effect upon DOC concentration explained only 1% of the variance in the data. The results suggest that drain blocking works by decreasing the flow from the drain, not by changing the production of DOC in the peat. The change in export with catchment size implies a considerable removal of DOC from large catchments. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

17.
The aim of this study was to assess the level of heavy metals (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) contamination and enrichment in the surface sediments of the Seyhan River, which is the receiving water body of both treated and untreated municipal and industrial effluents as well as agricultural drainage waters generated within Adana, Turkey. Sediment and water samples were taken from six previously determined stations covering the downstream of the Seyhan dam during both wet and dry seasons and the samples were then analyzed for the heavy metals of concern. When both dry and wet seasons were considered, metal concentrations varied significantly within a broad range with Al, 7210–33 967 mg kg?1 dw; Cr, 46–122 mg kg?1 dw; Cu, 6–57 mg kg?1 dw; Fe, 10 294–26 556 mg kg?1 dw; Mn, 144–638 mg kg?1 dw; Ni, 82–215 mg kg?1 dw; Pb, 11–75 mg kg?1 dw; Zn, 34–146 mg kg?1 dw in the sediments while Cd was at non‐detectable levels for all stations. For both seasons combined, the enrichment factor (EF) and the geo‐accumulation index (Igeo) for the sediments in terms of the specified metals ranged from 0.56 to 10.36 and ?2.92 to 1.56, respectively, throughout the lower Seyhan River. The sediment quality guidelines (SQG) of US‐EPA suggested the sediments of the Seyhan River demonstrated “unpolluted to moderate pollution” of Cu, Pb, and Zn, “moderate to very strong pollution” of Cr and Ni. The water quality data, on the other hand, indicated very low levels of these metals suggesting that the metal content in the surface sediments were most probably originating from fine sediments transported along the river route instead of water/wastewater discharges with high metal content.  相似文献   

18.
Alia?a Bay is one of the most important maritime zones of Turkey where shipping activity, shipbreaking industry, steel works and petrochemical complexes exist together. Concentrations of heavy metals and organic carbon in sediment of the Alia?a Bay were investigated to evaluate an environmental risk assessment from metals contamination in 2009-2010. Comparison of the metal concentrations with average shale and Mediterranean background levels revealed that most of the samples from the Alia?a were polluted with Hg, Cd, Pb, Cr, Cu, Zn, Mn and Ni. It was found that Hg, Pb, Cu, Zn and Ni levels in Alia?a Bay exceeded the PEL values. Sediments, contaminated with Pb, Cr, Cu, Zn and Ni were considered as heavily polluted per the SQG.  相似文献   

19.
The impact of copper mining along the western coast of Marinduque Island was investigated. Historic input of mine tailings in the coastal region was traced through variations in heavy metal concentrations in Porites growth bands. Five samples were collected from three reefs showing different modes and extent of exposure to mine tailings. Baseline metal concentrations in Porites were established using a coral from a reef that is least exposed to contamination. The lowest mean values of Cu (0.7 microg/g), Mn (0.8 microg/g), and Zn (1.0 microg/g) were calculated from annual skeletal bands representing five years of growth. Conversely, a sample from a reef adjacent to an old tailings stockpile displayed consistently elevated metal values in its growth bands. Mean Cu, Mn, and Zn values for this coral are 3.1, 1.0 and 1.8 microg/g, respectively. Corals from the Ihatub reef showed a distinct metal concentration peak in their 1996 growth ring. These peaks coincide with a documented release of mine tailings in the Ihatub area during that year. Other metal peaks observed in coral samples correlate with years of high precipitation which may have resulted in increased sediment transport in the region. The metals are presumed to be mostly bound to the aragonite lattice of the coral skeleton, however, contribution from incorporated detrital materials to the observed metal signal (mainly of Fe) could not be easily discounted.  相似文献   

20.
Brown algae are often used as heavy metal biomonitors and biosorbents because they can accumulate high concentrations of metals. Cation-exchange performed by cell wall polysaccharides is pointed out as the main chemical mechanism for the metal sequestration. Here, we biochemically investigated if the brown alga Padina gymnospora living in a heavy metal contaminated area would modify their polysaccharidic content. We exposed non-living biomass to Cd and Pb and studied the metals adsorption and localization. We found that raw dried polysaccharides, sulfate groups, uronic acids, fucose, mannose, and galactose were significantly higher in contaminated algae compared with the control ones. Metal concentrations adsorbed by non-living biomass were rising comparatively to the tested concentrations. Electron microscopy showed numerous granules in the cell walls and X-ray microanalysis revealed Cd as the main element. We concluded that P. gymnospora overproduces cell wall polysaccharides when exposed to high metal concentrations as a defense mechanism.  相似文献   

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