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1.
Silva L. F. F. Machado W. Lisboa Filho S. D. Lacerda L. D. 《Water, air, and soil pollution》2003,145(1-4):67-77
The Hg accumulation in sedimentary environments of a mangrove ecosystem in Sepetiba Bay, SE Brazil, was investigated. These environments include sediments of a mangrove forest, the main tidal creek that drains the forest, and the bare seaward-edge mud flat adjacent to forest and tidal creek. Maximum Hg concentration peaks in sediments from the mud flat (184 ng g-1), tidal creek (98 ng g-1), and mangrove forest (60 ng g-1) correspond to enrichment factors of 6.1, 3.3, and 2.0 above the estimated average background level, respectively. Average inventories of Hg excess (background-corrected) concentrations were substantiallydifferent between environments, decreasing from mud flat sediments (5.2 mg m-2) to creek sediments (3.3 mg m-2)to mangrove forest sediments (0.9 mg m-2). Mercury concentration profiles indicated a consistently higher accumulation of Hg in surface layers of mud flat and tidal creeksediments, whereas mangrove forest sediments showed a higher Hgaccumulation in root-rich subsurface layers, in agreement with an enrichment of Fe and organic matter contents. While Hg distribution in mud flat and tidal creek sediments appears to belargely affected by contamination, its distribution in mangrove forest substrate appears to be greatly affected by root-sedimentinteractions. Mercury levels in the study site were comparable tothose observed in coastal sediments under moderate Hg contamination at local and regional scales. Results indicate thatsedimentary environments surrounding the mangrove forest retain most of the anthropogenic Hg reaching the ecosystem. Since tidal waters have been previously demonstrated as the main source of metals to the site, it is suggested that the Hg retention in mudflat sediments precede and may avoid a higher Hg accumulation inlandward environments. 相似文献
2.
Katia N. Suzuki E. C. Machado W. Machado A. V. B. Bellido L. F. Bellido J. A. Osso Jr. R. T. Lopes 《Water, air, and soil pollution》2012,223(7):3887-3892
Microcosm experiments on the behaviour of Se, Cr and Co were carried out with mangrove sediments from Sepetiba Bay, Brazil. Three 8-cm length sediment cores were covered with tidal water spiked with 75Se, 51Cr and 60Co to evaluate its behaviour within the sediments. Two cores retained almost all activities (99?C100?%) within the uppermost centimetre layer, while the third core presented a deeper penetration of all radiotracers, displaying a second activity peak at the 3?C4-cm depth interval, which evidenced benthic fauna bioturbation influence. This influence extended the diffusion into depths in which mangrove rhizosphere can retain the elements, suggesting increased retention efficiency. This mechanism of retention enhancement was proposed in addition to previous conceptual models describing trace elements behaviour in mangrove sediments. Increased bioturbation and rhizosphere development will probably increase this effect, while mangrove plant cover losses may promote a less efficient retention of elements recently diffused from tidal water. 相似文献
3.
Veronica Bianchi Grazia Masciandaro David Giraldi Brunello Ceccanti Renato Iannelli 《Water, air, and soil pollution》2008,188(1-4):323-333
Metal (Cu, Mn, Ni, Zn, Fe) concentrations in marine sediment and zooplankton were investigated in Izmir Bay of the Eastern Aegean Sea, Turkey. The study aimed to assess the levels of metal in different environmental compartments of the Izmir Bay. Metal concentrations in the sediment (dry weight) ranged between 4.26–70.8 μg g?1 for Cu, 233–923 μg g?1 for Mn, 14.9–127 μg g?1 for Ni, 25.6–295 μg g?1 for Zn, 12,404–76,899 μg g?1 for Fe and 38,226–91,532 μg g?1 for Al in the Izmir Bay. Maximum metal concentrations in zooplankton were observed during summer season in the inner bay. Significant relationships existed between the concentrations of certain metals (Al, Fe, Mn and Ni) in sediment, suggesting similar sources and/or similar geochemical processes controlling such metals. Higher concentrations of Cu, Zn and percent organic matter contents were found in the middle-inner bays sediments. Based on the correlation matrix obtained for metal data, organic matter was found to be the dominant factor controlling Cu and Zn distributions in the sediment. In general, mean Cu and Zn levels in the bay were above background concentrations in Mediterranean sediments. Zooplankton metal concentrations were similar to sediment distributions. 相似文献
4.
Cristian Mugnai Rosa M. Bertolotto Federico Gaino Christian Tiberiade Luca G. Bellucci Silvia Giuliani Stefania Romano Mauro Frignani Sonia Albertazzi Davide Galazzo 《Water, air, and soil pollution》2010,211(1-4):69-77
Due to its remarkable sediment pollution caused by past industrial activities, the Mediterranean coastal area facing the town of Cogoleto (near Genoa) has been declared of “national interest”. Seven sediment cores were analysed to provide information on history and trend of heavy metal inputs, with a particular focus on Cr. Grain-size compositions and 210Pb chronologies account for a strong influence of terrigenous inputs near the coast and the mouth of the Lerone Creek (draining the industrial settlement), with sand contents and accumulation rates varying from 40.3% and 0.7 cm year?1 near shore to 2.5% and 0.1 cm year?1 offshore. Heavy metal concentrations are high, notably Cr and Ni, and to a lesser extent, Ag, Hg, Pb, Cu and Zn. Cr, that shows past values up to 3,642 µg g?1, presents only minor recent decreases. In the area, it has both natural and anthropogenic sources and their relative contributions were distinguished on the basis of Cr/Ni ratios. These are 1–1.5 in soils and rocks of the Lerone Creek catchment area but reach very high values (up to 10) in marine sediments due to the anthropogenic contribution. The anthropogenic influence is higher near the creek mouth, gradually decreases offshore and is negligible at the most distal site (ca. 2.9 km from the coast). 相似文献
5.
Phosphorous dynamics within Lake Sirio (NW Italy) were investigated, considering both water and sediments. The total phosphorus (TP) concentration in the water is about 79 μg l?1 after the winter mixing, that is in homogeneous conditions; then TP content increases up to an average of 360 μg l?1 in late autumn in the deep hypolimnium (30–45 m). This deep lake portion accounts for only 1/12 of the water volume. Close to the water-sediment interface, TP concentrations up to 530 μg l?1 are observed. Sediment sampled at depths of 20 and 33 m contains less than 2,000 mg kg?1 of TP, whereas cores from the deepest sediments (46 m) display TP values of 2,000–4,000 mg kg?1 at the water-sediment interface, increasing with depth to 16,000 mg kg?1 at about 60–100 cm. In these deep sediments the main chemical form is the Al–Fe–Mn bound P (about 90% in the high TP cores) and Fe and Mn are also highly enriched (3 and 9 times more than in the shallow sediments respectively). The P–Fe association is confirmed by SEM-EDS and XRD analyses. The vertical distribution of the P content in the water column is consistent with its release from sediments, but in this hypothesis an unrealistic P release rate from 8.1 to 3.0 g m?2y?1 was estimated. A more complex model is therefore proposed, involving a process of P concentration in the sediments of the central (deepest) part of the lake, and a short term sediment-water exchange. The TP vertical variability and speciation in the cores suggests a change in the sediment retention capacity, connected to the lake shift to more eutrophic conditions. 相似文献
6.
Lacerda L. D. Rezende C. E. Aragon G. T. Ovalle A. R. 《Water, air, and soil pollution》1991,57(1):513-520
Water, Air, & Soil Pollution - The export and import of Fe and Cr through a mangrove tidal creek and their further accumulation in bottom sediments were studied in a mangrove forest at the... 相似文献
7.
Sumit Sen Brian E. Haggard Indrajeet Chaubey Kristofor R. Brye Thomas A. Costello Marty D. Matlock 《Water, air, and soil pollution》2007,179(1-4):67-77
Phosphorus (P) release from bottom sediments can be a significant source to the overlying water column, potentially maintaining and enhancing algal growth and eutrophic conditions in lakes and reservoirs. Thus, the objectives of this study were to: (1) measure P flux under aerobic and anaerobic conditions from intact sediment cores collected at Beaver Reservoir, northwest Arkansas, (2) evaluate the spatial variability in measured sediment P flux under aerobic and anaerobic conditions along the reservoir, and (3) compare external and internal P loads to Beaver Reservoir. Six intact sediment cores were collected at three sites representing the lacustrine, transitional, and riverine zones during June 2003, September 2003 and February 2004 and incubated for 21 days in the dark at ~22°C. Three cores from each site were incubated under aerobic conditions and anaerobic conditions. Water samples were collected from the overlying water column in each core daily for the first five days and every other day thereafter and analyzed for soluble reactive phosphorus (SRP). Water removed from the core was replaced with filtered lake water, maintaining a constant overlying water volume of 1 l. Sediment P flux under anaerobic conditions (<0.01–1.77 mg m?2 day?1) was generally greater than that measured under aerobic conditions (<0.01–0.89 mg m?2 day?1). Some spatial variability existed in sediment P flux where P flux was generally greatest at the sites in the riverine and transitional zones. Maximum sediment P flux was observed under anaerobic conditions in cores collected from the transitional zone during September 2003. Average sediment P flux under aerobic conditions (0.09 mg m?2 day?1) and anaerobic conditions (0.31 mg m?2 day?1) was greater than the external P flux (0.05 mg m?2 day?1) estimated from the Beaver Reservoir tributaries. Results showed that the annual internal P load (7 Mg year?1) from bottom sediments in Beaver Reservoir was less than 10% of the annual external P load (~81 Mg P year?1). The internal P load was significant, but it would not currently be cost effective to manage this P source given the large surface area of Beaver Reservoir. 相似文献
8.
Annie Melinda Paz-Alberto Arnel B. Celestino Gilbert C. Sigua 《Journal of Soils and Sediments》2014,14(1):251-258
Purpose
Coal-fuelled power plants can discharge hazardous materials, particularly heavy metals such as lead (Pb). An alternative way of reducing Pb concentration from contaminated sediments is through phytoremediation. Presently, there are few research findings on the phytoremediation potential of mangroves on metals like Pb. The study was conducted to survey and identify mangroves that thrive near the coal-fired power plant and to assess the phytoremediation potential of mangroves on Pb in sediment.Materials and methods
The study sites were located in the mangrove ecosystems of Sitio Oyon and Sitio Asinan in Masinloc, Zambales, Philippines. The first stage of our study was to survey and identify the mangrove species. The second stage was to assess the levels of Pb in the sediments, water, and tissues of mangrove trees. The diversity assessment of the mangrove species was done through the use of 10?×?12 m quadrat technique. Water and sediment samples from each mangrove ecosystem were collected using composite sampling methods.Results and discussion
Three mangrove species were identified in the study sites: Avicennia marina, Rhizophora stylosa, and Sonneratia alba. The order of importance of the mangrove trees in the two sampling locations, based on an importance value index (IVI), were as follows: SA (IVI?=?171.20)?>?AM (77.79)?>?RS (51.01). The total uptake of Pb from sediments near the power plants varied significantly (p?≤?0.001) among the three mangrove species. S. alba had the highest Pb uptake of 48.4 kg ha?1 followed by A. marina (23.1 kg ha?1), and R. stylosa (2.4 kg ha?1). These three mangrove species have the potential to phytoremediate Pb in the sediment.Conclusions
The three mangrove species present in the coastal ecosystem near the electric power plant—A. marina, R. stylosa, and S. alba—were potential phytoremediators of sediment Pb. The present study indicated that the mangroves possess beneficial characteristics that remove Pb from contaminated sediments in areas directly affected by coal-fired power plants, and thus have potential phytoremediation properties. 相似文献9.
Anthropogenic Heavy Metal Pollution in the Surficial Sediments of the Keratsini Harbor, Saronikos Gulf, Greece 总被引:1,自引:0,他引:1
Stavroula Galanopoulou Andreas Vgenopoulos Nikolaos Conispoliatis 《Water, air, and soil pollution》2009,202(1-4):121-130
The contents of ten elements [Cd, Pb, W, Zn, Mn, As, Se, Cr, Cu, and organic carbon (Corg)] have been determined in the surficial sediments of Keratsini harbor, Saronikos Gulf, Greece. The contamination of the sediments was assessed on the basis of geoaccumulation index and to corresponding sediment quality guidelines (SQGs) effects range low/effects range median. The results revealed highly elevated Cd, Pb, W, Zn, As, Se, Cr, Cu, and Corg values (Cd, 190–1,763 mg kg?1; Pb, 521–1,263 mg kg?1; W, 38–100 mg kg?1; Zn, 409–6,725 mg kg?1; Mn, 95–1,101 mg kg?1; As, not detectable–1,813 mg kg?1; Se, not detectable–58 mg kg?1; Cr, 264–860 mg kg?1; Cu, 195–518 mg kg?1; and Corg, 0.69–4.41%). The enrichment of metals in the sediments results from the contribution of the central Athens sewage outfall through which the waste of the Attica basin ends up in Keratsini harbor as well as from industrial and ship contaminants. 相似文献
10.
Investigation of Nitrification and Denitrification in the Sediment of Wastewater Stabilization Ponds
Chema Keffala Marcello Galleguillos Ahmed Ghrabi Jean-Luc Vasel 《Water, air, and soil pollution》2011,219(1-4):389-399
Kinetic studies of nitrification and denitrification were carried out on reconstituted cores of sediments taken from wastewater stabilization ponds. This study aims to quantify the nitrification and denitrification in the sediment and to offer kinetic models to describe the processes. Sediment cores were collected, and laboratory studies were performed. The result showed that nitrification and denitrification processes are absent in the water column of stabilization ponds of the Bertrix (Belgium) wastewater treatment plant. On the contrary, nitrification and denitrification rates measured on 18 cores of sediment are, respectively, in the range of 0.12?C1.56 g N-NH 4 + /m2 day and 0.1?C1.2 g N/m2 day. In order to describe nitrification and denitrification processes, two kinetic models were developed using the Monod standard equation. 相似文献
11.
Historical Profiles of Trace Element Concentrations in Mangrove Sediments from the Ba Lat Estuary,Red River,Vietnam 总被引:1,自引:0,他引:1
Nguyen Tai Tue Tran Dang Quy Atsuko Amano Hideki Hamaoka Shinsuke Tanabe Mai Trong Nhuan Koji Omori 《Water, air, and soil pollution》2012,223(3):1315-1330
Historical profiles of trace element concentrations were reconstructed from two mangrove sediment cores collected within the
Ba Lat Estuary (BLE), Red River, Vietnam. Chronologies of sediment cores were determined by the 210Pb method, which showed that each respective sediment core from the south and north entrances of BLE provided a record of
sediment accumulation spanning approximately 100 and 60 years. The profiles of Pb, Zn, Cu, Cr, V, Co, Sb, and Sn concentrations
markedly increased from the years of the 1920s–1950s, and leveled out from 1950s–1980s, and then gradually decreased from
1980s to present. The profiles of Cd and Ag concentrations increased from 1920s–1940s, and then decreased from 1940s to present.
The profile of Mo concentrations progressively increased from 1920s–1980s, then decreased to present. The Mn concentrations
failed to show a clear trend in both sediment cores. Results from contamination factors, Pearson’s correlation, and hierarchical
cluster analysis suggest that the trace elements were likely attributed to discharge of untreated effluents from industry,
domestic sewage, as well as non-point sources. Pollution Load Index (PLI) revealed levels higher than other mangrove sediment
studies, and the long-term variations in PLI matched significant socioeconomic shifts and population growth in Vietnam. Geoaccumulation
Index showed that mangrove sediments were moderately polluted by Pb and Ag, and from unpolluted to moderately polluted by
Zn, Cu, and Sb. The concentrations of Pb, Zn, Cu, Cr, and Cd exceeded the threshold effect levels and effect range low concentrations
of sediment quality guidelines, implying that the sediments may be occasionally associated with adverse biological effects
to benthic organisms. 相似文献
12.
《Communications in Soil Science and Plant Analysis》2012,43(15-16):2033-2045
Abstract Soils under the main mangrove (Rhizophora racemosa and Avicennia germinans) forest in the Niger Delta, Nigeria, were characterized, and their capacities to retain heavy metals were examined by using soil column leaching experiments, using 20 mg L?1 Cu, 50 mg L?1 Zn, 20 mg L?1 Cd, and 100 mg L?1 Mn solutions. At the end of the leaching experiments, soil samples from each column were divided into two layers (0–5 cm and 5–10 cm) and analyzed for total metal retained. The fractionation of heavy metals in the surface soil samples (0–5 cm) was investigated by the sequential extraction technique. The study showed that the soils were influenced by tidal flow and characterized by the presence of very fine textured, thin (0–5 cm) to moderately thick (10–15 cm) layer of alluvium (mud) on the surface. The fibric soil material beneath the surface mud varies in thickness from about 70 to 100 cm, and beyond the histic layer is the plastic, very sticky, massive clay. In situ, the soils were neutral in reaction (pH 7.0–7.2), but became strongly acid (pH 3.3–4.8) upon drying. They are saline, high in soluble salts, highly reduced, with CEC that is low in the fibric layer, but high in the mineral, clayey subsoil horizon. The soils are saturated with water for much more than 30 days in a year and have fiber content that is more than 40 cm thick, with the fibric sphagnum constituting more than three‐fourths by volume to a depth greater than 90 cm. The soils, classified as Typic Sphagnofibrists, sequestered considerable amounts of copper (Cu), zinc (Zn), cadmium (Cd), and manganese (Mn) with most of the metals retained in the surface soils. The anthropogenic heavy metals were mostly adsorbed probably to the negatively charged sites of organics and clay. These loosely bound metals may be desorbed and reenter the aqueous phase, thus becoming a secondary source of metal pollution. 相似文献
13.
Rute Cesário Holger Hintelmann Nelson J. O’Driscoll Carlos E. Monteiro Miguel Caetano Marta Nogueira Ana M. Mota João Canário 《Water, air, and soil pollution》2017,228(7):257
Mercury (Hg) dynamics was evaluated in contaminated sediments and overlying waters from Tagus estuary, in two sites with different Hg anthropogenic sources: Cala Norte (CNOR) and Barreiro (BRR). Environmental factors affecting methylmercury (MMHg) production and Hg and MMHg fluxes across sediment/water interface were reported. [THg] and [MMHg] in solids (0.31–125 μg g?1 and 0.76–201 ng g?1, respectively) showed high variability with higher values in BRR. Porewater [MMHg] (0.1–63 ng L?1, 0.5–86% of THg) varied local and seasonally; higher contents were observed in the summer campaign, thus increasing sediment toxicity affecting the sediment/water Hg (and MMHg) fluxes. In CNOR and BRR sediments, Hg availability and organic carbon were the main factors controlling MMHg production. Noteworthy, an upward MMHg diffusive flux was observed in winter that was inverted in summer. Although MMHg production increases in warmer month, the MMHg concentrations in overlying water increase in a higher proportion compared to the levels in porewaters. This opposite trend could be explained by different extension of MMHg demethylation in the water column. The high concentrations of Hg and MMHg and their dynamics in sediments are of major concern since they can cause an exportation of Hg from the contaminated areas up to ca. 14,600 mg year?1 and an MMHg deposition of up to ca. 6000 mg year?1. The results suggest that sediments from contaminated areas of Tagus estuary should be considered as a primary source of Hg for the water column and a sink of MMHg to the sedimentary column. 相似文献
14.
Purpose
The main objective of this study was to evaluate the potential of a counter-current leaching process (CCLP) on 14 cycles with leachate treatment at the pilot scale for Pb, Cu, Sb, and Zn removal from the soil of a Canadian small-arms shooting range.Materials and methods
The metal concentrations in the contaminated soil were 904?±?112 mg Cu kg–1, 8,550?±?940 mg Pb kg–1, 370?±?26 mg Sb kg–1, and 169?±?14 mg Zn kg–1. The CCLP includes three acid leaching steps (0.125 M H2SO4?+?4 M NaCl, pulp density (PD)?=?10 %, t?=?1 h, T?=?20 °C, total volume?=?20 L). The leachate treatment was performed using metal precipitation with a 5-M NaOH solution. The treated effluent was reused for the next metal leaching steps.Results and discussion
The average metal removal yields were 80.9?±?2.3 % of Cu, 94.5?±?0.7 % of Pb, 51.1?±?4.8 % of Sb, and 43.9?±?3.9 % of Zn. Compared to a conventional leaching process, the CCLP allows a significant economy of water (24,500 L water per ton of soil), sulfuric acid (133 L H2SO4 t–1), NaCl (6,310 kg NaCl t–1), and NaOH (225 kg NaOH t–1). This corresponds to 82 %, 65 %, 90 %, and 75 % of reduction, respectively. The Toxicity Characteristic Leaching Procedure test, which was applied on the remediated soil, demonstrated a large decrease of the lead availability (0.8 mg Pb L–1) in comparison to the untreated soil (142 mg Pb L–1). The estimated total cost of this soil remediation process is 267 US$ t–1.Conclusions
The CCLP process allows high removal yields for Pb and Cu and a significant reduction in water and chemical consumption. Further work should examine the extraction of Sb from small-arms shooting range. 相似文献15.
Fingerprinting sediment sources in the outlet reservoir of a hilly cultivated catchment in Tunisia 总被引:1,自引:1,他引:1
Abir Ben Slimane Damien Raclot Olivier Evrard Mustapha Sanaa Irène Lefèvre Mehdi Ahmadi Mouna Tounsi Cornelia Rumpel Abdallah Ben Mammou Yves Le Bissonnais 《Journal of Soils and Sediments》2013,13(4):801-815
Purpose
Approximately 74 % of agricultural soils in Tunisia are affected by water erosion, leading to the siltation of numerous human-made reservoirs and therefore a loss of water storage capacity. The objective of this study was to propose a methodology for estimating the relative contributions of gully/channel bank erosion and surface topsoil erosion to the sediment accumulated in small reservoirs.Materials and methods
We tested an approach based on the sediment fingerprinting technique for sediments collected from a reservoir (which has been in operation since 1994) at the outlet of a catchment (Kamech, 2.63 km2). Sampling concentrated on the soil surface (in both cropland and grassland), gullies and channel banks. A total of 17 sediment cores were collected along a longitudinal transect of the Kamech reservoir to investigate the origin of the sediment throughout the reservoir. Radionuclides (particularly caesium-137, 137Cs) and nutrients (total phosphorus, total nitrogen and total organic carbon (TOC)) were analysed as potential tracers.Results and discussion
The applications of a mixing model with 137Cs alone or 137Cs and TOC provided very similar results: The dominant source of sediment was surface erosion, which was responsible for 80 % of the total erosion within the Kamech catchment. Additionally, we showed that the analysis of a single composite core provided information on the sediment origin that was consistent with the analysis of all sediment layers in the core. We demonstrated the importance of the core sampling location within the reservoir for obtaining reliable information regarding sediment sources and the dominant erosion processes.Conclusions
The dominance of surface erosion processes indicates that conservation farming practices are required to mitigate erosion in the agricultural Kamech catchment. Based on the results from 17 sediment cores, guidelines regarding the number and location of sampling cores to be collected for sediment fingerprinting are proposed. We showed that the collection of two cores limited the sediment source apportionment uncertainty due to the core sampling scheme to <10 %. 相似文献16.
Stefano Covelli Elisa Petranich Leonardo Langone Andrea Emili Alessandro Acquavita 《Journal of Soils and Sediments》2017,17(7):1972-1985
Purpose
Previous research conducted in the Marano and Grado lagoon (northern Adriatic Sea) has shown that this environment has been affected by trace metal contamination, especially by mercury (Hg), from both industrial (the chlor-alkali plant) and mining activities (Idrija mine, Slovenia). Sediment cores were collected from two different saltmarshes of this lagoon environment to evaluate the degree of the anthropogenic enrichments and the geochronology of Hg accumulation.Materials and methods
Core subsampling was performed by cutting 1-cm thick slices at discrete intervals. Mercury determination was done differently from the other parameters in that the two long cores were subsampled at 1-cm intervals to obtain continuous concentration profiles. Samples were completely decomposed, using a mixture of mineral acids in a closed microwave system before being analysed for trace metal content using ICP-OES. Total Hg content in the solid phase was determined by DMA-80. 137Cs was measured via gamma spectrometry. 210Pb activity was measured via alpha-counting of its daughter, 210Po, assuming secular equilibrium between the two isotopes.Results and discussion
In saltmarsh sediments, Fe, Co, Li, Sc and V show no enrichment at both sites thus suggesting that they are essentially lithogenic elements. Conversely, enrichments are minimal (EF = <2) for As, Cd, Cr, Ni, Pb and Zn and moderate (EF = 2–5) for Cu and Mn and also for Pb and Zn but only in some levels of the sedimentary sequences. An exception is Hg, as expected due to the long-term input proceeding from the historical mining activity which has especially affected the eastern sector of the lagoon.Conclusions
The core collected from the saltmarsh in the eastern lagoon (Grado) displays a better time resolution during the last century although the Hg background level has not been reached. Conversely, the core collected in the western sector (Marano) has recorded a longer and more complete history of Hg contamination, from the beginning of the peak of Hg extraction activity at the Idrija mine (1850). Both saltmarshes still receive Hg inputs and the sediment accumulation rates in the upper section appear to have increased over the last 10–20 years (from 0.30 to 0.45 cm year?1 at Marano and from 0.30 to 0.74 cm year?1 at Grado). Many of these morphological structures suffer erosive processes thus representing a potential source of contaminants associated with sediments, in particular Hg. Conservation and monitoring of saltmarshes should be taken into consideration also from this environmental point of view.17.
Mercury Partitioning in Surface Sediments of the Upper St. Lawrence River (Canada): Evidence of the Importance of the Sulphur Chemistry 总被引:1,自引:0,他引:1
João Canário Laurier Poissant Nelson O`Driscoll Jeff Ridal Tania Delongchamp Martin Pilote Philipe Constant Jules Blais David Lean 《Water, air, and soil pollution》2008,187(1-4):219-231
An intensive survey of mercury speciation was performed at a site on the Upper St. Lawrence River near Cornwall, Ontario, Canada with a history mercury contamination in sediments. Surface sediments were collected every 1.50 h. Total mercury (Hgtotal), methylmercury (MeHg), organic carbon, inorganic and organic sulphur were determined in the solid fraction. Dissolved Hgtotal, MeHg and dissolved organic carbon (DOC) were measured in pore waters. Concentrations of Hgtotal in the upper layers (first 5 cm) were high, ranging from 1.42 to 25.8 nmol g?1 in solids and from 125 to 449 pM in pore waters. MeHg levels were also high, ranging from 4.34 to 34.1 pmol g?1 in solids and from 40 to 96 pM in pore waters. This amounts to up to 1.4% of Hgtotal present as MeHg in solids and 64% in pore waters. A daily pattern for Hgtotal was observed in the solid fraction. The MeHg distribution in solids and pore waters was not correlated with Hgtotal or DOC, suggesting that the concentrations of MeHg are probably more influenced by the relative rates of methylation/demethylation reactions in the sediment–water interface. Acid volatile sulphide levels and DOC were inversely correlated with organic sulphur (Sorg) levels suggesting that both parameters are involved in the rapid production of Sorg. A positive correlation was also observed between Hgtotal and Sorg in solids (R?=?0.87, p?<?0.01) illustrating the importance of organic sulphur in the retention and distribution of Hg in the solid fraction of the sediments. The results suggest that variations of Hgtotal concentrations in Upper St. Lawrence River surface sediments were strongly influenced by the formation/deposition/retention of organic sulphur compounds in the sediment–water interface. 相似文献
18.
Carolina Melgar Violette Geissen Silke Cram Mikhail Sokolov Pedro Bastidas Luz E. Ruiz Suárez Francisco Javier Que Ramos Aaron Jarquín Sanchez 《植物养料与土壤学杂志》2008,171(4):597-604
The aim of this study was to investigate how long‐term Mancozeb application to banana plantations affects the occurrence of pollutants in drainage‐channel sediment and water under tropical conditions. We estimated the possible accumulation of Mancozeb's principal metabolite ethylenethiourea (ETU), as well as manganese (Mn) and zinc (Zn) as components in channel sediment and water. We took samples during the tropical‐rainfall season and the low‐rainfall season. For sediment samples, we determined the contents of ETU, Mn, and Zn. For water samples, we determined the concentration of ETU. Additionally, we took water samples from a runnel that is the receiving body of hydraulic flow from the system. In both seasons, ETU in the sediment was near the detection limit (0.01 mg kg–1) and did not show any accumulation. However, Mn in sediment at all sampling sites exceeded the threshold values for aquatic life of 630 mg kg–1 with values between 635 and 7256 mg kg–1. The Zn concentrations in sediment varied from 87 to 190 mg kg–1 and exceeded the threshold values for aquatic life of 98 mg kg–1 at several sites. Furthermore, we determined an accumulation of these heavy metals in the sediments of the banana‐planted zone in comparison with sediments in pasture reference sites. In contrast to the low concentration of ETU in sediment, its concentration in drainage and runnel water (5.9–13.8 μg L–1) exceeded the EU threshold value for drinking water (0.1 μg L–1) by up to nearly 140 times. However, the threshold value for aquatic life was not exceeded. We conclude that long‐term Mancozeb application does lead to a severe accumulation of Mn in sediments and of ETU in surface water. New strategies should be used to control black Sigatoka, including integrated methods of pest control so that long‐term negative effects on the environment can be avoided. 相似文献
19.
Martyna A. Rzętała 《Journal of Soils and Sediments》2016,16(10):2458-2470
Purpose
Cadmium (Cd) is considered a toxic element and its concentrations are relevant to human health and the environment. Therefore, the purpose of the study was to determine the extent to which the bottom sediments of water bodies (artificial lakes and ponds) in the Silesian Upland in southern Poland are contaminated with Cd; an attempt was also made to determine the factors that condition spatial differences in the concentration of this element between individual water bodies in the region.Materials and methods
Measurements of the Cd content in bottom sediments were carried out in 35 water bodies in southern Poland in 2011 and 2012. Depending on the surface area and morphometric characteristics, from two to nine samples representative in terms of sediment thickness were collected in each water body. Cadmium concentrations were determined for 92 0.25 g aliquots using the TD-ICP method.Results and discussion
Cadmium content in all samples (0.7–580.0 mg kg?1) was higher than the natural range of concentrations for this element in the Earth’s crust (0.1–0.3 mg kg?1) and the geochemical background for Poland (0.5 mg kg?1) and, with a few exceptions, was also higher than the preindustrial concentration (1.0 mg kg?1) and the regional geochemical background (2.5 mg kg?1). Adopting natural Cd concentrations in the Earth’s crust (0.1–0.3 mg kg?1) as the baseline for the geoaccumulation index (Igeo), the sediments examined can be classified as extremely and heavily contaminated (and moderately contaminated in a small number of cases). The assessment of sediment quality based on Igeo, with the regional geochemical background (2.5 mg kg?1) adopted as the baseline, results in non-contaminated and moderately contaminated sediments being dominant with a far smaller number of heavily and extremely contaminated ones.Conclusions
In the case of several water bodies, Cd concentrations were at record levels that have not been found anywhere else in the world. On the basis of the Igeo, sediments of varying quality were found—from virtually uncontaminated to extremely contaminated. The Igeo index as an indicator of the quality of bottom sediments is a measure that requires careful interpretation, especially when different concentration levels regarded as natural are used for determining its value.20.
Andreas Zehnsdorf Heinz Seidel Petra Hoffmann Uwe Schlenker Roland A. Müller 《Journal of Soils and Sediments》2013,13(6):1106-1112