首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
To investigate the influence of mangrove reforestation on heavy metal accumulation and speciation in intertidal sediments, core sediments from a restored mangrove forest and adjacent mud flat in Yifeng Estuary (southeastern China) were analyzed. The chemical speciation of heavy metals (Pb, Zn, Cu, Cr and Ni) was determined according to a sequential extraction procedure. Special attention was paid to the upper 20 cm of sediment, in which metal accumulation was enhanced and speciation was obviously modified. Mangrove reforestation decreased the concentrations of all metals in the acid-soluble fraction and increased metal concentrations in the oxidizable fraction. Increased Pb, Zn and Cu concentrations and decreased Ni and Cr concentrations were observed in the reducible fraction. These results suggest that mangrove reforestation facilitated the accumulation of heavy metals in the upper sediment layers but decreased their bioavailability and mobility.  相似文献   

2.
太湖流域滆湖底泥重金属赋存特征及其生物有效性   总被引：1，自引：0，他引：1  
包先明  晁建颖  尹洪斌 《湖泊科学》2016,28(5):1010-1017
为了探讨太湖流域滆湖底泥重金属(Cd、Cr、Cu、Zn、Ni和Pb)的赋存特征及其生物有效性,对底泥重金属总量、形态以及生物富集量进行了分析.结果表明,6种重金属含量的空间分布表现为北部湖区最高,其次为南部湖区,中部湖区最低,重金属Ni、Cu、Zn和Pb含量显著高于沉积物背景值,分别是背景值的4.77、3.89、2.96和2.76倍,重金属总量与沉积物中的黏土成分含量具有显著相关性.采用三级四部提取法对重金属形态进行分析表明,6种重金属的生物有效态(弱酸结合态、可还原态和可氧化态之和)含量顺序为CdCuZnPbNiCr,其中Cd、Cu、Zn和Pb的生物有效态含量分别占总量的84.15%、78.47%、76.50%和64.29%.Cu和Zn在铜锈环棱螺中富集含量要显著高于其他金属元素.相关性分析表明,6种重金属中仅Cr和Pb的生物富集量与有效态含量具有显著相关性,这表明,重金属在生物体内的富集不仅与有效态含量有关,还与底泥重金属总量有关.因此,评价滆湖重金属的生态风险时需要综合考虑重金属的总量及生物有效态含量.  相似文献   

3.
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   

4.
The concentrations of Cr, Mn, Fe, Ni, Cu, Zn, and Pb metals in soil samples (N = 21) were determined by flame atomic absorption spectrometry. The modified Community Bureau of Reference (BCR) sequential extraction procedure (three‐step) was used in order to evaluate mobility, availability, and persistence of heavy metals in soil samples taken from an agricultural area in Erciyes University Campus. The operationally defined fractions isolated using the BCR procedure were: acid extractable, reducible, and oxidizable. The mobility sequence based on the sum of the BCR sequential extraction stages was: Mn (70.2%) > Pb (62.9%) > Ni (26.7%) > Cr (15.4%) > Zn (14.4%) > Cu (12.9%) > Fe (1.24%). Multivariate statistical analysis was used to define the possible origin of heavy metals in soils. Correlation analysis, principal component analysis (PCA), and cluster analysis (CA) were applied to the data matrix to evaluate the analytical results and to identify the possible pollution sources of heavy metals. PCA results revealed that the sampling area was mainly influenced from three sources, namely natural, airborne emissions from domestic heating and traffic.  相似文献   

5.
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   

6.
The concentrations of 45 elements, and the content of organic substances, amorphous inorganic substances and minerals were determined in 26 samples of Elbe River bottom sediments to determine the correlation between the element composition and the grain size in the ￡ \le 4, 4--8, 8--16, 16--32, 32--63 7m and bulk samples ￡ \le 63 7m fractions. The purpose of this study was to obtain information about the role of particle size and their mineral composition as a control of element concentrations in sediments, the potential remobilization of elements under changing environmental conditions, and the chemical speciation of the large excess concentrations of elements in this system.¶About 22--56% of the estimated element yield was associated with sediments with a grain size of less than 4 7m and 82--97% of the element yield was found in the fraction smaller than 32 7m. Sequential extraction carried out for 20 potentially reactive elements in the ￡ \le 63 7m bulk samples and the ￡ \le 4 7m fraction showed the increased importance of exchangeable ions in the order Mn = Ni < Mg < Sr < Cu < Zn < Ca < K < Cd < Na < Mo, reducible fractions Zn < Sr < Mo < Co < Cu < Ni < Pb < Mn < Cr < Be < V = Fe < As < Ag, oxidizable chemical phases As = Ca < Cd < K < Sr < Fe = Mn < Zn = Mg < Mo < Co = Ag < Pb < Li < Cu = V < Ni < Cr = Na < Be with small concentrations from lithogenic phases Mn < As < Pb < Sr < Zn = Cu = Na < Be < V < Ni < Cr < Fe < K < Mg < Li. The major accumulative phases were identified for the individual elements.  相似文献   

7.
Freshwater lakes are one of the most vulnerable ecosystems to environmental contamination. This study was initiated to assess the spatial distribution, fractionation, ecological risk of selected potentially toxic metals (Pb, Zn, Cu, Cr, and Ni) in bottom sediments of the Zarivar lake, the second largest freshwater lake in Iran. The results revealed that Pb, Zn and Cu had the high spatial variability (coefficient of variation >50) across the sampling sites and their maximum concentrations (197.5 for Pb, 198.7 for Zn and 185.6 mg/kg for Cu) were observed in sampling sites from the northern, western and eastern margins of the lake. Cr and Ni with average concentrations of 28.3 and 31.38 mg/kg respectively, exhibited low spatial variability (coefficient of variation <20) and their concentrations did not vary significantly among the sampling sites. Based on the redundancy analysis (RDA), sediment organic matter was strongly correlated with Pb, Zn and Cu while Fe2O3 and Al2O3 showed a positive correlation with Ni and Cr. The calculated average enrichment factor (EF) and geoaccumulation index (Igeo) showed that the contamination level of metals can be arranged in the following order of Pb> Cu > Zn > Cr > Ni. Results from the modified five-step sequential extraction analysis indicated that 40 % of total Pb and Zn were associated with the reducible fraction, 45 % of Cu with the oxidizable fraction and more than 80 % of total Ni and Cr were retrieved from the residual fraction. It was also noticed that Pb, Zn and Cu were more incorporated into the non-residual fractions in the sites with a higher total concentration of these metals, suggesting that both total concentration and fractionation behavior of metals were influenced by their potential sources in the study area. Ecological risk assessment using the potential ecological risk index (PERI) and the modified potential ecological risk index (MPERI) showed that sediments from the eight sampling sites pose a moderate to considerable risk whereas the other sites had low ecological risk level. In comparison to sediment quality guidelines (SQGs), the effects range low (ERL) and probable effect level (PEL) values for Pb, Cu and Zn were exceeded at some sampling sites while Ni and Cr concentrations were found to be below or close to their SQGs values at all the sampling sites. Pb was generally identified as the contaminant of most concern in the study area. Taking into account the results obtained from the fractionation study and the source contribution estimate, it can be inferred that the Pb, Zn and Cu with the average contribution of 79, 54 and 64 % respectively, were mainly derived from anthropogenic sources whereas Ni and Cr with the estimated contribution of 80 and 89 % were predominately from the lithogenic source.  相似文献   

8.
The purpose of this study was to assess the chemical partitioning of selected heavy metals(Fe,Mn,Cu,Zn,Pb,Cr,Co and Ni) in 10 surface sediments at Tirumalairajan River Estuary in the southeastern coast of India.A five-step sequential extraction technique was used to assess the environmental status of heavy metals.Most of metals were considered to be immobile due to the high availability in the residual fraction of heavy metals.The sediments of Tirumalairajan River estuary had not been polluted by heavy metals,and they didn’t pose any high ecological risk.The seasonal variations of heavy metals were slightly higher in summer than in monsoon season.Factor analysis was also carned out to understand the associations of metals in different fractions with sand,silt,clay,organic matter,pH,salinity and other metals.The relationship between the Q-mode and R-mode cluster analyses was useful for identifying the pollution levels in both seasons.It was proved that the enrichment of heavy metals was related with geogenic and anthropogenic sources.The information on total metal concentrations in sediments was not sufficient for assessing the metal behavior in the environment,but the sequential extraction technique was more effective in estimating the environmental impact of contaminated sediments.  相似文献   

9.
By means of the analysis of sediments cored in the small river Gurk (Carinthia/Austria), the input of Ag, Cd, Ce, Cr, Hg, La, Mo, Ni, V, and W from a chemical industrial plant could be detected. To estimate the actual load, and to obtain data for comparison with other sites, both unsieved fine sediments and sediments sieved to 20 μm were investigated from the same cores. Environmental mobilities of toxic heavy metals (Co, Cr, Cu, Ni, Zn) have been shown by sequential leaching following Tessier/Förstner. In the last step, HNO3 leaches a purely geogenic fraction, which is fairly constant along the investigated river. Whereas the additional Cr from the input of the chemical plant is mainly found in the oxalate-leachable fraction, short-time-load to unpolluted sediments in the laboratory is found mainly in hydroxylamine/acetic acid. Both is due to the high affinity of Cr to Fe- and Mn-oxides. Adsorption/desorption experiments reveal that the low carbonate content of the Gurk sediments increases the importance of Fe/Mn-oxides for the sorption of Cr compared to other samples containing carbonate. The Ni-load was primarily found in weak-acid-leachable and oxalate-leachable fractions. Similarly, the oxalate-leachable fraction is dominant for adsorption of other metals and phosphorus. Other interelement relationships among the amounts leached, which are attributable partly to carbonate-, silicate-, organic or coating phases, have been found by means of factor analyses together with marker fractions for each type.  相似文献   

10.
苏州河网区河道沉积物重金属的污染特征   总被引：5，自引：0，他引：5  
分析测定了苏州河网区河道底泥十个剖面样点60个样品中Cu、Pb、Zn、Cr、Al、Fe、K、Mn、有机质、TP、TN、粒度、pH及含水量,采用地累积指数、生态风险指数和相关分析等方法研究其重金属污染特征.结果表明:Cu和Zn处于中或中-强度污染,Pb处于无-中污染,没有Cr污染;垂直分布特征显示:Cu和Zn污染逐年变化较为一致,Pb污染有逐年加重趋势;重金属潜在生态风险处于轻微污染状态;相关性分析显示,有机质是影响其分布的重要因素,Mn、Cr、Cu、Zn、Pb五种重金属相关性显著;通过与国内外河流、水库和湖泊沉积物中重金属含量比较,苏州河网区河道重金属的累积受多种因素影响.  相似文献   

11.
抚仙湖沉积物重金属时空变化与人为污染评价   总被引：11，自引：3，他引：8  
分析了抚仙湖表层沉积物及沉积短岩芯中10种金属元素含量,结合沉积年代学,定量研究了Cr、Cu、Ni、Pb、Zn的污染特征及时空变化规律;参考沉积物质量基准与潜在生态风险指数法探讨了表层沉积物重金属的潜在生态风险.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,近岸地区重金属含量总体上高于湖心区;Pb、Zn含量自1980s中期以来逐渐增加,而Cr、Cu、Ni含量呈下降趋势.重金属富集系数与聚类分析结果表明,抚仙湖沉积物主要重金属污染元素为Pb、Zn,污染开始于1980s中期,并逐渐加重.表层沉积物中Pb、Zn富集系数分别为1.6~4.1和1.4~2.6,已达到弱—中等污染程度,北部湖区污染程度略高于南部湖区;除此之外,北部湖区近岸区域Cr污染程度也略高于其他湖区.除了大气沉降来源之外,抚仙湖沉积物重金属污染还可能与入湖河流输入有关.单因子生态风险指数表明,表层沉积物中Cr、Cu、Ni、Pb、Zn具有较低的潜在生态风险;而综合潜在生态风险指数表明,表层沉积物中重金属具有中等程度的潜在生态风险,这与根据沉积物质量基准所获得的评价结果一致.  相似文献   

12.
40年来江苏石梁河水库重金属污染的沉积记录   总被引：1，自引：1，他引：0  
根据石梁河水库沉积物粒度和重金属元素(Cu,Cr,Zn,As和Pb)含量的分析,结合137Cs放射性比活度精确定年,研究了石梁河水库沉积速率和重金属的污染变化特征,并利用地累积指数法评价了重金属的污染程度.结果表明:石梁河水库 40年来平均淤积速率为3.85cm/a,Cu,Cr和zn地累积指数一直小于1,处于轻微污染;As污染水平变化较大.现处于低水平的轻度污染;Pb污染水平自柱底始持续恶化,目前地累积指数大于1,且有污染加剧趋势.  相似文献   

13.
利用富集因子和Hakanson潜在生态风险指数法,结合年代学结果,对长江中下游湖泊太白湖、龙感湖、巢湖和西氿沉积物中重金属元素Co、Cr、Cu、Ni、Pb、Zn的富集程度进行了评价,并比较分析了上述重金属的潜在生态风险.结果表明,太白湖和龙感湖沉积物中各重金属富集程度均较低;巢湖沉积物中Co、Cr、Ni的富集程度接近中等水平,而Cu、Pb、Zn的富集已经达到中等水平;西氿沉积物中Co的富集非常低,Cr、Ni富集水平较低,Pb达到中等富集,Cu、Zn达到较高的富集水平.对4个湖泊沉积物中重金属的综合污染程度进行比较:巢湖西氿龙感湖太白湖.各湖泊沉积物中单一元素的潜在生态风险都较低,但是,根据多元素潜在生态评价指数,各湖泊沉积物中重金属存在明显不同的潜在生态风险:巢湖西氿龙感湖太白湖.总体上看,太白湖和巢湖沉积物重金属污染以及潜在生态风险自1965年以来一直在加重,而龙感湖和西氿沉积物在表层有下降的趋势.这种差异与各个湖泊流域内人类活动的方式和强度密切相关.巢湖和西氿流域内城市化、工业化发展迅速,人类活动导致大量重金属元素进入湖泊,给湖泊带来明显的污染;而龙感湖和太白湖流域人类活动主要以农业活动为主,人类活动对重金属的贡献相对较小.  相似文献   

14.
This study aimed to evaluate the spatial and temporal distribution of heavy metals (Cd, Cr, Cu, Co, Fe, Pb, Ni, V, and Zn) in the sediments of Bayan Lepas Free Industrial Zone of Penang, Malaysia. Ten sampling stations were selected and sediment samples were collected during low tide (2012 ? 2013). Metals were analyzed and the spatial distribution of metals were evaluated based on GIS mapping. According to interim sediment quality guidelines (ISQG), metal contents ranged from below low level to above high level at different stations. Based on the geoaccumulation index (Igeo) of sediment, sampling stations were categorized from unpolluted to strongly polluted. The enrichment factor (EF) of metals in the sediment varied between no enrichment to extremely high enrichment. The potential ecological risk index (RI) indicated Bayan Lepas FIZ was at low risk.  相似文献   

15.
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   

16.
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   

17.
Sediment samples were collected from ten selected sites of the lower Meghna River estuary, and six heavy metals were analyzed with Atomic Absorption Spectrophotometry(AAS) to assess the contamination level and the metals' association with sediment grain size. The current results revealed that the mean concentrations of the studied metals were ranked in descending order of iron(Fe)(1.29 ? 103 mg/kg) zinc(Zn)(42.41 mg/kg) lead(Pb)(12.48 mg/kg) chromium(Cr)(10.59 mg/kg) copper(Cu)(6.22 mg/kg) cadmium(Cd)(0.28 mg/kg). The geo-accumulation, contamination, and pollution load indexes suggested that the lower Meghna river estuary was not contaminated by Fe, Zn, Pb, Cr, and Cu.The mean size of the sediment ranged from 28.92 to 126.2 mm, and the Pearson correlation coefficient showed a significant association between Fe and Pb(coefficient of determination, r2? 0.836; p 0.05),and no significant correlation was found between individual metals and grain size, indicating no or low influence on the metals distribution.  相似文献   

18.
Heavy metal (Hg, Pb, Cd, Cu, Cr, Ni, Co, Zn and Fe) concentrations, textural characters and mineralogical compositions have been determined on 246 surface sediment samples from the Northern Adriatic Italian sea area. The relationship between the heavy metals content and the pelite (< 63 μm fraction) percentage has been studied. All the metals resulted accumulated in the fine fraction with the following percentages (Hg, 95%; Zn, 86%; Pb, 82%; Cu, 79%; Cd, 74%; Ni, 70%; Cr, 65%; Co, 65% and Fe, 64%). The specific surface area has been measured on 44 samples and correlated to metal values. A fairly good (50% and more variation explained) linear correlation co-efficient has been found for Ni and Cu in the entire area, less significant correlation for other metals. In order to discriminate between natural and anthropogenic origin the metal concentrations on the whole sediment has been normalized on the basis of the pelite percentage. In the areal distributions drawn with the corrected values, zones contaminated by industrial discharges have been identified mainly in front of the lagoon of Venice.  相似文献   

19.
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   

20.
为识别表层沉积物重金属的来源以及量化源贡献,选取鄱阳湖丰水期表层沉积物为研究对象,测定14种重金属(V、Cr、Co、Ni、Cu、Zn、Sr、Mo、Cd、Sb、W、Pb、Hg和As)的含量,分析其污染及空间分布特征,并利用主成分分析法(PCA)和正定矩阵因子分解法(PMF)对沉积物重金属进行源解析.结果表明:除V和Cr外,Cd、Mo、Hg、Cu、Pb、Zn、W、Sr、As、Ni、Co和Sb的平均含量分别为江西省土壤背景值的5.7、2.2、1.9、1.8、1.5、1.5、1.4、1.3、1.3、1.2、1.0和1.0倍; Cd、Hg、Cu、Mo、Pb、Sr和Zn超出江西省土壤背景值的比例相对较高,分别为100%、100%、100%、100%、97%、97%和93%,所有沉积物样品中Cd含量超过农用地土壤污染风险筛选值的比例为51%; V、Cr、Co、Ni、Cu、Zn、Sr、Mo、Sb、W、Pb、Hg和As含量呈未污染至弱污染水平,而Cd含量属于中等污染水平,接近于重污染水平.总体而言,Cd的污染相对较严重.重金属的分布具有显著的区域特征,其中Cr、Cu、Zn、Sr、Pb、Hg和As的空间分布十分相似,表现为在赣江、抚河、信江和饶河入湖口附近区域含量较高,而Co、Ni、Mo和Sb明显在湖区南部、东北部和修水入湖附近这3个区域聚集,Cd和W的空间变异性相对较大,V的含量分布相对较均匀.PCA和PMF解析结果都表明鄱阳湖丰水期表层沉积物重金属受4种来源的共同影响,其中,矿业和工业活动的影响最大,相对贡献率为38%,其次是尾矿和废渣,相对贡献率为28%,再是农业活动,相对贡献率为19%,最后是自然来源的相对贡献率为14%.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号