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1.
Metal pollution study on sediments of North Bay of Bengal sediments presented in this paper is based on existing Lithostratigraphy of upstream,mineralogy and geochemical analysis of 42 sediment samples.The statistical analysis identifies the metal pollution as well as its apparent source in the off shore regions.Samples were analyzed for grain size,organic content and heavy metals(Fe,Mn,Cr,Cu,Ni,Pb,Cd,Zn and Co) using the sequential extraction method to evaluate geochemical processes and pollution load.In an effort to surmise anthropogenic input,several approaches including classification by quantitative indexes such as enrichment factor,contamination factor,degree of pollution,pollution load index and geo accumulation index,were attempted.Metal speciation results indicate high%of Cd in exchangeable fraction of Mahanadi transect sediments where as a considerable amount of oxidizable fraction of Cr was detected at Dhamra.Quantitative indexes place North Bay of Bengal under moderately polluted zone due to high level of Cd.Normalization of metals to Fe indicated relatively high enrichment factors for Cd and Cr.Factor analysis identified seven possible types of geochemical associations where sediment pH plays a major role for the heavy metal mobility.The higher Cd concentration in exchangeable fraction as well as the higher EF for Cd and Cr present in sediment may pose a risk of secondary water pollution under slightest disturbance in the geo-chemistry of sediments.Comparison study with available data of near costal zones and upstream stratigraphy revealed that open cast mining,overburden dumping,mineral based industrial effluents were the major source of pollution for catchment area contamination.Bay of Bengal is likely to face a serious threat of metal pollution with the present deposition rates unless rigorous pollution control norms are applied.  相似文献   

2.
Baseline levels of a number of trace metals have been determined in samples of water and sediment from Baffin Bay. Concentrations of Cr, Mn, Fe, Ni, Cu and Cd in the waters of Baffin Bay are generally lower than those observed in eastern Canadian coastal waters, levels being close to reported open ocean concentrations. Nearshore sediment samples, analysed for Cr, V, Mn, Ni, Co, Cu, Zn, Hg and Pb, display comparable concentrations to unpolluted muds in eastern Canadian coastal regions. Concentrations of these elements in the deep sediments of central Baffin Bay closely resemble levels in Atlantic Ocean deep-sea clays.  相似文献   

3.
Dil Deresi stream is a highly contaminated stream passing through the most heavily industrialized area of Izmit Bay. In this research, surface sediments in the <63-microm fraction collected from 34 sites at western part of Izmit Bay, Northeastern Marmara Sea, Turkey were analyzed by ICP-AES for Al, As, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sn and Zn. Metal concentrations were compared with the marine sediment quality standards (SQS) and literature data to assess the pollution status of the sediments. Enrichment factors (EFs) were calculated to assess whether the concentrations observed represent background or contaminated levels. The analysis revealed three groups of elements: (1) Sn is the most enriched element; (2) As, Cd, Pb and Zn are minor enriched elements; and (3) Co, Cr, Cu, Fe, Mg, Mn and Ni are at background concentrations. The distribution maps of the concentrations and enrichment factors for all heavy metals were also produced as a contour plot based on Geographic Information System (GIS) technology.  相似文献   

4.
The concentration and areal distribution of selected trace metals (Cu, Zn, Pb, Cd, Mo, Ni, Mn and Hg) in surficial sediments of Saint John Harbour, New Brunswick, Canada, were studied to determine the extent of anthropogenic input and to estimate the effects of dumping dredged material in the outer harbour. Hg and Cd are of especial concern, since the disposal of dredge material containing these two elements is regulated under the Ocean Dumping Control Act.The concentrations of all metals are low: Cu 16, Zn 53, Pb 24, Cd 0.16, Mo 3, Ni 16, Mn 296 and Hg 0.04 μg g?1. Hg and Cd levels in sediments are well below the permissible limits of 0.75 and 0.6 μg g?1, respectively, set by the Ocean Dumping Control Act.The mean concentrations of trace elements are similar to the low mean values in the unpolluted Bay of Fundy. There is an overall decline in concentrations of metals in the sediments from the inner to the outer harbour. Comparison of the metal levels in the sediments from different areas within the harbour indicate that there is a detectable anthropogenic input in the Courtenay Bay area. Trace metal levels at the dumpsite are significantly lower than in the Courtenay Bay area, where the bulk of the dredged material originates.  相似文献   

5.
Gao X  Li P 《Marine pollution bulletin》2012,64(8):1529-1536
Surface sediments from intertidal Bohai Bay were sampled for the geochemical and environmental assessment of six trace metals (Cd, Cr, Cu, Ni, Pb and Zn). Results indicate that sediment grain size plays an important role in controlling the distribution and fractionation of them. Metal concentrations in clayey silt sediments are all clearly higher than in sand and silty sand ones. Cd and Pb in clayey silt sediments are more mobile than in sand and silty sand ones. Two sediment quality guidelines and two geochemical normalization methods (index of geoaccumulation and enrichment factor) were used to judge the potential risk and accumulation of metals. According to the mean probable effects level quotient, the combination of studied metals may have a 21% probability of being toxic. The sediments with high fraction of clay and silt have been contaminated by trace metals to various degrees, among which Cr contributes the most to contamination.  相似文献   

6.
The distribution of trace metals in Florida Bay sediments   总被引：1，自引：0，他引：1  
The distribution of trace metals based on surface sediments collected at 40 stations across Florida Bay was done in June, November and February 2000-2001. Concentrations of Sc, V, Ba, Cd, Cr, Co, Cu, Pb, Mn, Ni, Zn, Al and Mg were determined by ICP-MS, and the total Fe was determined by spectrophotometry. Organic carbon (OC), nitrogen (N), and calcium carbonate (CaCO3) were also measured. Eleven of 13 metals showed a similar distribution pattern for the various months studied. Maximum concentrations of metals were lower than those found in most estuarine systems and were concentrated in the north-central and western zones of the Bay. The Mn and Fe concentrations, unlike the other metals, gradually decreased from north (Everglades) to south (Florida Keys). Some metals (Ni, Zn, Cu, Cr, Pb and Ba) associated with petroleum use showed high concentrations at stations near the Tavernier marina. Florida Bay sediments are predominately CaCO3 (65.9-92.5%). The greatest value for OC (5.5%) and the lowest value of CaCO3 (65.9%) were found in the western zone. Trace metal distribution patterns are similar to the OC and N in the sediments. There was a strong correlation between most metals (V>Cu>Ni>Cr>Al>Co>Ba>Zn>Pb>Mg) and the percentage of OC. The maximum C/N values (9-12) were observed at the stations with the highest OC, where dense colonies of seagrass are found and most of the metals are concentrated. All metals except Mg, Mn and Co showed a strong correlation with Al and the fine fraction of the sediments (aluminosilicates) associated with continental input and river runoff.  相似文献   

7.
Natural variation in concentrations of Cd, Co, Cu, Ni, Pb, and Zn in sediments of Cleveland Bay can be modelled by linear regression by using the concentration of Al recovered by strong acid digestion as an independent variable. Samples that exceed the upper 95% prediction interval of regression models are classified as enhanced. Enhancement of trace metals occurs in the intertidal zone and near-shore sediments of western Cleveland Bay, in sites that are characterized by high accumulation rates of fine grained terrigenous sediment. There is a strong positive relationship between increasing enhancement of Cu and Pb and the recovery of these metals by weak HCl digestion, which suggests that for these metals the modelled enhancement is environmentally meaningful. In contrast, at least 60%, and generally greater than 80% of Cd is recovered by weak HCl digestion irrespective of modelled enhancement, and suggests that the statistically modelled enhancement of Cd may be more meaningful than weak HCl soluble concentrations.  相似文献   

8.
The trace metal distribution in the sediments of Laucala Bay, a coastal lagoon with a barrier reef and significant freshwater input, adjacent to Suva, the capital of Fiji (150,000 people), was studied from the point of view of assessing the significance of anthropogenic sources relative to natural ones. Surface sediments from 25 sites in the Bay were analysed for particle size distribution, organic carbon and major (Si, Al, Fe, Ca, Mg) and trace metal (Mn, Zn, Cu, Pb, Cd, Hg) contents. Suspended sediments from one site and shellfish samples from five sites were also analysed. The sediments were found to be mostly of terrigenous origin. Particle size distribution, organic carbon and major elemental composition of the sediments were generally related to location within the Bay. A significant natural source of trace metals in the sediments is the suspended solids transported into the Bay by rivers. The spatial distribution of trace metals could not be fully explained by the particle size distribution and mineral composition of the sediments. Contributions from anthropogenic sources were also suspected, but the degree of enrichment from such sources is not great at the present time.  相似文献   

9.
巢湖沉积物重金属富集特征与人为污染评价   总被引：15，自引：6，他引：9  
本文分析了巢湖主要入湖河流河口区表层沉积物及西部湖心区沉积岩芯中Al、Fe、Ni、Cr、Cu、Zn、Pb、Li、V等金属元素变化特征,采用地球化学方法对金属元素变化的"粒度效应"进行矫正,并以Li、V为参照元素对矫正结果进行检验;参考历史沉积物,对河口区及西部湖心区沉积物重金属人为污染特征进行分析;结合沉积岩芯210Pb年代结果,估算西部湖心区近150a来Ni、Cr、Cu、Zn、Pb等重金属元素的人为污染贡献量.结果表明,河口表层沉积物重金属污染具有显著的空间差异,南淝河河口重金属人为污染最重,其中Ni、Cr、Cu、Zn、Pb的人为污染贡献量分别为12.2、32.2、25.3、479.9和76.0 mg/kg,分别占总含量的35%、37%、64%、92%和77%;其次是柘皋河河口,主要重金属污染元素为Cu、Zn和Pb,人为污染贡献量达57.6、57.0和19.5 mg/kg,分别占总含量的73%、47%和36%;而派河、白石山河、杭埠河等河口表层沉积物中重金属元素人为污染程度较弱.巢湖西部湖心区主要污染元素为Cu、Zn、Pb,人为污染开始于1950s,1980年以来其人为污染贡献量显著增加,平均为16.2、245.6、47.8 mg/(m2.a),分别占各元素沉积通量的23%、61%和37%;Ni人为污染开始于1980s初期,人为污染贡献量平均为12.6 mg/(m2.a),占其沉积通量的13%左右;Cr基本未受人为污染影响.西部湖心区沉积岩芯及南淝河河口表层沉积物中重金属污染程度均表现为Zn>Pb>Cu,而且南淝河河口沉积物重金属污染程度显著高于西部湖心区.结合主要入湖河流径流量与河口沉积物重金属污染特征,认为巢湖西部湖心区重金属污染主要通过南淝河输入,来自合肥等城市的废水是主要的污染源.  相似文献   

10.
Sediment from twelve stations was sampled from the Tupilipalem Coast, southeast coast of India, and the presence of a set of heavy metals was established including iron (Fe), manganese (Mn), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn) and cadmium (Cd). The heavy metals were assessed by factor analysis, the results of which showed positive and/or negative correlations among Fe, Mn, Cr, Cu, Ni, Pb, Zn, and Cd. Factor analysis also indicated that heavy metals in the sediments of the study area have different natural and anthropogenic sources. Similarly, a sediment pollution assessment was done using the Geoaccumulation Index (Igeo), Enrichment Factor (EF), and Pollution Load Index (PLI). The Geoaccumulation Index indicated that the surface sediment of the Tupilipalem Coast was extremely contaminated with Fe, Mn, Cr, Cu, Ni, Pb, and Zn. The calculation of enrichment factors showed a significant enrichment with respect to Pb, Zn, and Cd and a moderate enrichment with Cr, Cu, and Ni. The falling trend of average contents’ enrichment factors is Cd> Pb> Zn> Cu> Cr> Ni> Mn> Fe. The PLI values of the Cd show higher (>1) values due to the influence of distinct external sources like agricultural runoff, industrial activities, and other anthropogenic inputs. Ninety two percent of heavy metals under study showed the highest concentrations at station TP-5 where the Buckingham Canal and other agricultural and aquacultural effluents connect with the Bay of Bengal. This location is the second inlet which is periodically closed and it seemed that these parts of the study area are heavily affected by anthropogenic pollution.  相似文献   

11.
Surface sediments collected from the Pearl River Estuary (PRE) and the Daya Bay (DYB) were analyzed for total metal concentrations and chemical phase partitioning. The total concentrations of Cr, Cu, Ni, Pb, and Zn in the PRE were obviously higher than those in DYB. The maximum concentrations of trace metals in DYB occurred in the four sub-basins, especially in Dapeng Cove, while the concentrations of these metals in the western side of the PRE were higher than those in the east side. Such distribution pattern was primarily due to the different hydraulic conditions and inputs of anthropogenic trace metals. The chemical partitioning of metals analyzed by the BCR sequential extraction method showed that Cr, Ni, and Zn of both areas were present dominantly in the residual fraction, while Pb was found mostly in the non-residual fractions. The partitioning of Cu showed a significant difference between the two areas.  相似文献   

12.
For a wide variety of substances aquatic systems are the medium of origin, or sinks in a longer or shorter lasting stay or even in geological periods. For surface sediments of Berlin waters and their surroundings this paper describes the enrichment and distribution of heavy metals (SM), which have a high priority under international aspects and a marked capability to geoaccumulation. From the 25 metals investigated Hg, Pb, Cu, Cd and Zn are of anthropogenic origin, all others are of geochemical provenience and correspond to background values. Some metals (Hg, Cd, Ni, Co, Cu, Cr and Pb) have specific concentration profiles with increasing depth of water and sediment. The study of correlation of SM in sediments demonstrates generally a strong relation to macroelements and between some metals themselves.  相似文献   

13.
分析了阳宗海柱状及表层沉积物中Al、Fe、Mn、Zn、Cr、Co、Ni、Cu、As、Cd、Pb等金属元素的含量,结合沉积年代学,研究了沉积物重金属污染的时空变化和潜在生态风险特征.结果表明,表层沉积物中重金属含量具有一定的空间差异性,As、Cd、Cu、Pb和Zn在中东部湖区含量较高,而Cr、Co、Ni含量高值位于南、北湖区的近岸区域;柱状沉积物中,1990s之前As、Cd、Cu、Pb和Zn含量较为稳定,1990s中后期以来,其含量逐渐增加,并在2009-2010年前后达到最大值,此后逐渐下降;而柱状沉积物中Cr、Co、Ni含量变化趋势与Al、Fe相似,总体上由下向上逐渐降低,这主要与沉积物质地(粒度)逐渐变粗有关.重金属富集系数表明,阳宗海沉积物中主要污染元素为As、Cd、Cu、Pb和Zn,1990s中后期污染程度快速增加,2009-2010年前后达到峰值,此后污染程度逐渐降低;表层沉积物中Cu为未污染至"弱"污染水平;Zn、Pb为"弱-中等"污染水平,As为"中等-强"污染水平,Cd为"弱-强"污染水平,中东部湖区污染程度高于其他湖区,这可能与该湖区缺少入湖径流、自然碎屑物质沉积速率较低以及砷污染事件等人为源的重金属贡献影响更为显著有关.生态风险评价结果表明,在2002-2010年前后沉积物重金属达到"中等-强"潜在生态危害,主要贡献因子是Cd和As,近年来其生态风险等级逐渐降低;表层沉积物中重金属在中东部湖区具有"中等"程度潜在生态危害,而其他湖区表层沉积物重金属具有较低程度的潜在生态风险.  相似文献   

14.
Metals in Sediments of the Upper Laguna Madre   总被引：2，自引：0，他引：2  
The Laguna Madre system is the largest hypersaline coastal basin in the United States. Surface sediments from 22 Upper Laguna Madre (ULM) sites were analyzed for grain size and metals (Cd, Cu, Ba, Cr, Mn, Ni, Pb, V, Zn, Fe, and Al) to assess the extent of contamination in the area. Sediments were found to consist mainly of sand texture. Clay and silts were minor constituents (<10%) of the sediments. Anomalies in metal concentrations were found at some sites and were related to probable sources, i.e., recreational and industrial activities. Concentrations of metals were normalized to grain size, Al, and Fe to distinguish natural and anthropogenic sources. Most metals showed positive correlations (p < 0.001) with Fe and Al, suggesting a natural variability of metal concentrations in sediments. Concentrations of metals, except Cd and Pb, at most sites were found to be below threshold concentrations thought to produce toxic effects in marine and estuarine organisms.  相似文献   

15.
The heavy metal inventory and the ecological risk of the tidal flat sediments in Haizhou Bay were investigated. Results show that the average concentrations of heavy metals in the surface sediments exceeded the environment background values of Jiangsu Province coastal soil, suggesting that the surface sediments were mainly polluted by heavy metals (Cd, Cr, Cu, Mn, Pb and Zn). In addition, the profiles of heavy metals fluxes can reflect the socio-economic development of Lianyungang City, and heavy metals inputs were attributed to anthropogenic activities. Cr, Cu, Pb and Zn were mainly present in the non-bioavailable residual form in surface sediments, whereas Cd and Mn were predominantly in the highly mobile acid soluble and reducible fractions. The ecological risk of the polluted sediments stemmed mainly from Cd and Pb. According to the Sediment quality guidelines (SQGs), however, the adverse biological effects caused by the heavy metals occasionally occurred in tidal flat.  相似文献   

16.
A survey on the metal concentrations (As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V, Zn) in beach water and sediments is reported from the tourist destination of Acapulco city on the Pacific coast of Mexico. The concentration of dissolved trace metals (DTMs) in beach water and acid leachable trace metals (ALTMs) in sediments indicated that they are anthropogenic in nature due to the increased tourist activities in the crowded beach locations. The statistical analysis indicates Fe and Mn play a major role as metal scavengers in both the medium (water and sediment) and the higher value of other metals is site specific in the study area, indicating that they are transported from the local area. Comparison results suggest that the beach water quality has deteriorated more than the sediments and special care needs to be taken to restore the beach quality.  相似文献   

17.
The Golden Horn is a heavily polluted water body in a large metropolitan area with a population of approximately 10 million. A 3-m long undisturbed core sample was collected in the Golden Horn, from research vessel RV Knorr, during the third leg of the joint Turkish--American Black Sea expedition in 1989. The core was sliced and dated using the 210Pb isotope technique. The bottom of the core corresponds to the year 1912. Each slice was analysed for major, minor and trace elements by inductively coupled plasma emission spectrometry (ICP). The masses of the measured elements can account for approximately half of the sediment mass. The lithophilic elements Li, K, Rb, Mg, Ca, Ba, Al, La, Ti, V, Mn, Fe, Co and Ni account for more than 90% of the elemental mass and do not show any change in their concentrations between 1912 and 1987. Although anthropogenic elements Mo, Zn, Cr, Cu, Ag, and Cd account for a minute fraction of the elemental mass, their concentrations increase along the core, signifying human influence on chemical composition of the Golden Horn Sediments. Lead was enriched at the bottom of the core suggesting pollution of Golden Horn sediments by this element even at the beginning of the century, but observed concentrations of the remaining anthropogenic elements, at the bottom of the core, can be explained by sedimentary material. Concentrations of pollution-derived elements do not change significantly between 1912 and 1950, but their concentrations increase sharply in the second half of the century. A factor analysis applied to the data set has shown that the inorganic fraction of the Golden Horn sediments includes crustal, marine and two anthropogenic components. One of the anthropogenic components is attributed to the discharges from an iron and steel plant. The second anthropogenic component, which accounted for a larger fraction of system variance, is due to discharges from industries, particularly metalwork plants.  相似文献   

18.
The particulate concentrations of 17 trace metals, Al, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Ag, Sb, Au, Hg, Pb and Th have been measured in the marine atmosphere (58 samples) and in the deep waters (35 samples) of the Tropical North Atlantic. For oceanic suspended matter, our results are similar to those in samples from the Atlantic and the Pacific Oceans collected during the GEOSECS Program. Based on these results, we have made a flux balance for the mixed layer between input via the atmosphere and removal through small and large particles. These data show that the primary flux of suspended aluminosilicates in the Tropical North Atlantic is attributable to the atmospheric input. Elements Sc, Th, Fe, V, Mn, Co and Cr show high correlation with Al in the marine atmosphere. Of these elements, Fe, Mn, V, Co and Cr are influenced by additional processes such as biological, in the marine environment. For elements Ni, Cu, Zn, Se, Ag, Sb, Au, Hg and Pb, we observe high enrichments (relative to average crustal material) in the marine atmosphere which may be due, at least partially, to the influence of anthropogenic sources. These metals also show similar enrichments in deep ocean suspended matter. Model calculations indicate that the atmospheric flux may not control the deep ocean particulate chemistry of Ni, Cu, Zn, Ag, Sb, Au and Hg. Hence it is likely that, for these elements, the enrichment in the ocean is due to processes within the marine regime, for example their involvement in the biological cycle of the ocean. For Se and Pb, the atmospheric source looks to be the dominant contribution to their particulate concentration in seawater. In the deep North Atlantic, particulate Pb appears to be mostly of anthropogenic origin, which is not the case for Se.  相似文献   

19.
This paper investigates the natural and anthropogenic processes controlling sediment chemistry in Admiralty Bay, King George Island, Antarctica, emphasizing the area affected by the Brazilian Antarctic Station Comandante Ferraz (Ferraz). Total and bioavailable concentrations of sixteen elements were determined in 32 sediment and 14 soils samples. Factor analysis allowed us to distinguish three groups of samples: (1) Ferraz sediments, with higher content of total trace metals and organic matter; (2) control sediments, with intermediate characteristics; (3) Ferraz soils, with higher bioavailability of most metals due to its oxidizing condition and low organic matter content. Major elements such as Fe, Al, Ca and Ti presented similar levels in all three groups. Enrichment factor calculations showed that paints, sewage and petroleum contamination enhanced metal concentrations in Ferraz surface sediments as follows: B, Mo, and Pb (>90%); V and Zn (70-80%); Ni, Cu, Mg, and Mn (30-40%). Despite evidence of contamination in these sediments, the low bioavailability, probably caused by iron-sulfide, indicates small environmental risks.  相似文献   

20.
太湖表层沉积物重金属元素的来源分析   总被引：42，自引：4，他引：38  
根据太湖MS岩芯重金属元素与Al的线性回归分析及元素/Al、V/Al比率散点图变化规律,讨论了太湖沉积物中重金属元素的来源特征。结果表明:20世纪20年代中期以前,重金属元素主要为自然来源;20年代中期—70年代中期,尽管沉积物中Al、Fe、Zn、Mn、V、Cr等重金属元素含量随沉积物粒度变粗而明显下降,但除Hg受到一定程度的人为污染之外,其它重金属元素仍以自然来源为主,物源有所变化;70年代末期以来,沉积物中重金属元素人为污染逐渐加重,Pb、Cu、Zn、Hg、As等元素既有流域母质来源,又受到一定程度的人为污染。  相似文献   

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