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1.
南京主要湖泊表层沉积物中重金属污染潜在生态风险评价   总被引:4,自引:0,他引:4  
为掌握南京城市湖泊表层沉积物中重金属的污染概况及其潜在生态风险,选取玄武湖、月牙湖、紫霞湖、琵琶湖和前湖5个主要湖泊为研究对象,应用电感耦合等离子体原子发射光谱法( ICP - AES)分析表层沉积物中Cd、Cr、Cu、Ni、Pb和Zn含量,并采用地累积指数法和潜在生态风险指数法对重金属污染风险和潜在生态危害进行评价.结果表明,湖泊表层沉积物中Cd、Cr、Cu、Ni、Pb和Zn含量分别为0.8~5.1、10.3 ~67.6、6.2 ~70.5、未检出~53.2、12.9 ~ 55.9和40.6 ~456.3 mg·kg -1.地累积指数法评价结果显示,6种重金属元素累积程度由高到低依次为Cd、Zn、Pb、Cu、Ni和Cr,其中Cd处于偏中等累积到重累积水平.潜在生态风险指数法评价结果显示,表层沉积物重金属污染最严重的是月牙湖,其次是前湖和紫霞湖,这3个湖泊都处于中等潜在生态风险状态,琵琶湖和玄武湖处于低潜在生态风险状态.  相似文献   

2.
滇池及其河口沉积物中重金属污染评价   总被引:6,自引:0,他引:6  
本文对滇池及其入湖河口表层沉积物中As、Pb、Cd、Cr、Cu、Zn和Hg等重金属含量进行了分析,并采用地质累积指数法和潜在生态风险指数法评价了其污染程度和生态危害.结果表明,滇池草海北部重金属含量最高,草海及其河口重金属污染强度明显高于外海及其河口;以"全国土壤环境质量标准"为依据,As和Cd是沉积物中主要的超标污染物.地质累积指数法评价结果表明,草海及其河口沉积物中Cd达到了"严重"污染程度,是主要重金属污染物,其他金属总体处于"中度"以下污染程度;外海及其河口所有重金属基本处于"清洁"到"偏中度"污染程度.潜在生态风险评价结果表明,草海及其河口沉积物总体上达到了"很强"的潜在生态危害程度,而外海及其河口大部分区域总体属于"低度"危害程度.Cd是最主要的潜在生态危害重金属污染物,其次是Hg、As、Pb和Cu,而Zn和Cr对潜在生态危害指数的贡献率很小,在整个研究区域产生的潜在生态风险均为"轻微".相关性和主成分分析结果表明,滇池表层沉积物中Cu、Pb、Zn、Cd、Hg和As可能有相似的污染来源,而Cr主要受地球化学成分影响.  相似文献   

3.
湘江长沙段沉积物重金属污染特征及其评价   总被引:4,自引:0,他引:4  
本研究用沉积柱钻探取样法获得湘江长沙段沉积物样品,利用等离子质谱仪(ICP-MS)分析沉积物中9种重金属含量,并利用X射线衍射仪(XRD)分析沉积物的矿物组成.在此基础上,利用地累积指数和潜在生态风险指数等方法,评价沉积物重金属污染程度.结果表明,湘江长沙段沉积物中重金属含量变化较大(CV﹥0.20),分布不均一.其中Mn、Zn、Pb、Cu、Cr、Co、Ni达中等-显著富集程度,而V、Th无明显富集.地累积指数和潜在生态风险评价结果显示,长沙段沉积物中Pb、Zn、Mn、Cu达偏中度至偏重度污染,Cr、Co、Ni、Th为轻污染.重金属存在轻至中等程度的潜在生态风险,其风险程度大小排序为:PbCuNiCoZnMnCrV.沉积物中Mn、Cu、Zn、Pb、Co、Ni、Cr、V可能与流域中上游矿石冶炼等人为活动带入有关,而Th可能来自流域岩石风化等自然过程.流域重金属污染防治中,应密切关注Mn、Cu、Zn、Pb等重金属引起的污染.  相似文献   

4.
为揭示滇池主要入湖河流沉积物重金属含量空间分布特征和污染状况,本研究在宝象河流域10个关键监测位点采集河流表层沉积物,运用X射线荧光光谱仪对其Zn、Cu、Cr、Pb、Ni含量进行测试,并使用地累积指数法、富集系数法、潜在生态风险评价法对该流域重金属污染状况进行评价.结果表明:(1)研究区Zn、Cu、Cr、Pb、Ni的含量分别为70—253、68—274、0—151、0—110、62—94 mg·kg-1,其含量均值分别是区域背景值的1.97、4.24、2.17、2.41、2.36倍.(2)3种评价结果表明,Zn在河流下游达到中等污染水平,富集程度也为中度;Cu在河流上游达到较强污染水平,并出现显著富集的情况;Cr、Pb、Ni在宝象河大部分河段为中等污染水平,富集程度也为中度.单一重金属污染程度依次为:CuNiPbCrZn,其中Cu在个别样点的生态危害系数超过40,属于中等生态危害,其余样点各种重金属生态危害系数都小于40,为轻微生态危害;各样点多种重金属潜在生态危害指数RI值均小于150,表现为轻微生态危害.从生态风险贡献率来看,Cu是宝象河重金属污染的主要贡献元素,应加以防范.  相似文献   

5.
为了解鄱阳湖与长江交汇区沉积物中重金属含量以及各污染物的潜在生态危害程度,通过采样分析As、Cd、Cr、Cu、Hg、Pb、Zn等7种重金属含量及污染特征分布的基础上,采用地积累指数法和潜在生态风险指数法对鄱阳湖底泥中的重金属污染进行综合性的评价分析.结果表明,鄱阳湖湖口段沉积物已经受到了不同程度的重金属污染;沉积物中Cd、Cu和Hg受人为影响比较严重,Cr、Cu、Hg、Pb和Zn均存在一定程度的积累;区域重金属元素潜在生态风险主要受制于Hg和Cu,潜在生态风险贡献率大小排序为:Hg(38.4%)Cu(27.8%)Pb(10.9%)Cd(9.1%)As(8.0%)Cr(4.0%)Zn(1.8%).  相似文献   

6.
为揭示太湖主要入湖河口表层沉积物重金属分布特征及其生态风险,采集太湖西岸和北岸12条主要入湖河口表层沉积物样品,对沉积物中5种重金属元素(Cu、Zn、Ni、Pb、Cd)的含量及空间分布特征进行了分析,并利用地累积指数法和潜在生态风险指数法分别研究了表层沉积物重金属的累积程度及生态风险。结果表明,调查的12条入湖河流河口表层沉积物均受到不同程度的重金属污染,Cu、Zn、Ni、Pb、Cd的平均质量分数分别为63.04、173.11、56.71、37.05、2.23 mg?kg~(-1)。各重金属在空间分布上具有差异性,总体表现为大港河(DGH)、乌溪港(WXG)庙渎港(MDG)、大浦港(DPG)、陈东港(CDG)、官渎港(GDG)、洪巷港(HXG)、社渎港(SDG)河口表层沉积物以重金属Cd污染为主,而沙塘港(STG)、太滆运河(TG)、直湖港(ZHG)、梁溪河(LXH)河口表层沉积物表现为Cu、Zn、Ni、Pb的复合污染。地累积指数法评价表明,各入湖河流河口表层沉积物重金属的污染程度表现为CdCuZnNiPb。潜在风险指数(riE)表明各重金属的潜在生态风险表现为CdCuNiPbZn,主要污染物为Cd。其中庙渎港(MDG)和社渎港(SDG)处于严重风险状态,大港河(DGH)、乌溪港(WXG)、大浦港(DPG)、官渎港(GDG)、洪巷港(HXG)处于重度风险状态,陈东港(CDG)、太滆运河(TG)处于中度风险状态,其余点位生态风险较低。研究表明,西岸入湖河流表层沉积物重金属潜在生态风险等级高于北岸,但北岸入湖河流河口表层沉积物中Cu、Zn、Ni、Pb的累积也应当得到重视。  相似文献   

7.
对镇江市古运河河岸7个表层沉积物中重金属As、Cu、Pb、Cd、Zn、Cr含量进行测定,并通过富集系数、地累积指数法、潜在生态风险评价以及主成分分析等对沉积物重金属的分布特征进行综合分析与评价.结果表明:(1)古运河河岸带沉积物Cr、Cu、Zn、As、Pb和Cd元素的含量平均值分别为45.07、41.70、254.06、19.67、45.88、0.75 mg·kg-1,p H平均值为7.98.对比《国家土壤环境质量标准》可知,沉积物中Cu、Zn、Pb、As属于超一级标准,而Cd属于超二级标准.(2)6种重金属的富集系数表现为:AsCdPbZnCuCr,且综合富集系数在空间上表现为:G2G5G1G4G3G7G6;(3)古运河河岸表层沉积物地累积指数表现为AsCdPbCuZnCr,6种重金属中As富集量最大,Cr的富集量最小.(4)单项潜在生态危害系数结果表明,Cr、Cu、Zn、Pb均为轻微生态危害程度,As和Cd处于中等生态危害程度.从RI值判断,古运河河岸沉积物总体处于轻微生态危害.(5)相关性和主成分分析结果表明,Pb、Cu、Cr、Cd是决定第一主成分的4个主要因子,且Cu与Pb、Cd以及Pb与Cd元素具有相同的污染源.As、Zn在第二主成分中具有较高的载荷值,且As与Zn之间的相关性较弱,表明这两种重金属并非来自同一污染源.  相似文献   

8.
为了解回龙河表层沉积物中重金属的污染状况,采集了表层沉积物样品,测定了重金属Zn、Cu、Pb、Cr、Cd和Ni的总量及其化学形态,并采用潜在生态风险指数法对重金属进行了生态风险评价。结果显示,回龙河表层沉积物中Zn、Cu、Pb、Cr、Cd和Ni均有一定程度的累积,总量分别为286.4~1277.9mg/kg、21.71~146.0mg/kg、10.33~44.20mg/kg、25.13~90.40mg/kg、0.07172~0.3901mg/kg、13.27~157.2mg/kg,其中Cu、Cr、Pb与Ni 4种重金属具有一定的同源特性;形态分析表明,Cu的形态分布以有机结合态为主,最容易迁移释放,Zn、Cr和Ni除残渣态外,铁锰氧化结合态和有机结合态占一定比例,具有潜在风险;潜在生态风险指数法分析表明,沉积物中重金属元素的单一潜在生态风险指数顺序为Cd〉Cu〉Ni〉Zn〉Pb〉Cr,潜在生态危害指数RI均小于150,总体上回龙河处于轻微的生态风险等级。  相似文献   

9.
对深圳湾15个表层沉积物中重金属Zn、Cu、Pb、As、Cd以及总有机碳(TOC)的含量进行测定,探讨了重金属污染特征,重金属之间及与TOC的相关关系,并利用潜在生态风险评价法进行潜在生态风险评估.结果表明,Zn、Cu、Pb、As和Cd平均值分别为307、79、75、23 mg·kg-1和2.26 mg·kg-1.Zn、Cu、Pb和As属于超Ⅰ类沉积物,Cd属于超Ⅱ类沉积物.Zn、Cu、Pb和Cd呈现相似的分布特征,即从东北向西南湾口逐渐减少.Zn、Cu、Pb、Cd、TOC彼此之间呈显著正相关.而As来源和分布与其余重金属明显不同,与其它重金属和TOC没有相关性.单因子污染系数显示Zn和Cd处于较高污染水平,Cu、Pb和As处于中等污染水平,污染程度依次为Cd>Zn>Pb>Cu>As.综合污染指数显示深圳湾总体达到较高污染水平.深圳湾重金属潜在生态风险总体处于中等水平,潜在风险程度依次为Cd>As>Pb>Cu>Zn,其中Cd的潜在风险最大.  相似文献   

10.
厦门市水体表层沉积物重金属污染生态风险分析   总被引:3,自引:0,他引:3  
沉积物是水环境的基本组成部分,其重金属含量常被作为水环境质量的重要指标之一。以厦门市为例探讨了不同城市化区域水体表层沉积物中重金属的分布特征,并采用沉积物地累积指数、Hakanson潜在生态风险指数等方法对重金属Zn、Pb、Cu、Cd、Cr、As、Hg进行环境风险评估。研究结果表明,厦门水体表层沉积物中Zn、Pb、Cu、Cd、Cr、As、Hg的含量分别为182.2、63.7、31.3、0.19、67.9、10.4、0.11 mg/kg,空间分布呈现出从城市远郊区到中心城区显著增加的趋势;依照地累积指数评价结果显示:7种重金属的污染程度顺序依次为:Hg(Pb(Zn(Cu(Cd(As(Cr;采用Hakanson提出的潜在生态危害指数法,获得厦门市主要水库重金属生态风险构成危害的顺序:Hg(Cd(Pb(As(Cu(Zn(Cr;水体表层沉积物中重金属污染水平与区域城市化水平在一定时期内呈正相关关系,这为我国快速城市化发展过程中水环境恶化问题的改善提出了警示。  相似文献   

11.
Sedimentation in artificial ports and harbors is a common issue throughout the world. Based on an assessment of the coastal fishing harbors in Egypt, the El-Burullus fishing harbor has been found to suffer severely from siltation. Sediment deposits are concentrated at the harbor entrance, which threatens navigation through this area. Although the harbor authority has constructed a perpendicular extension on the main breakwater to mitigate these siltation issues, fishing boats are still suffering from the siltation at the harbor entrance. Dredging is required every year to maintain continuity of navigation through the harbor; the cost of dredging is a critical element which impacts the economic feasibility of the harbor. Therefore, the need to investigate new solutions for the siltation issue is critical. In this study, a two-dimensional calibrated and validated model using the Coastal Modeling System package is used to understand the coastal processes within the study area. It is also used to investigate the effects of the proposed breakwater extension on the siltation at the harbor outlet. Field data such as hydrographic surveys, waves, tides, and lake outlet discharge data were collected and included in the model. The results obtained for the current breakwater conditions confirmed the claims of the fishermen that the sedimentation problem still occurs at the entrance. Thus, five possible solutions to mitigate the problem were proposed and simulated considering the following parameters: sediment deposition rate to the west of the main breakwater, the erosion rate in front of the seawall in the eastern part of the harbor, and the morphological changes within the El-Burullus lake outlet. According to the simulation results, reducing the length of the upper edge of the middle jetty by 90 m improves the stability of the harbor entrance. Alternatively, replacing the perpendicular extension by an inclined extension of 60 m in length and shortening the middle jetty by 60 m reduces the accretion and erosion rates around the harbor which promotes the long-term stability for the coastal area in addition to favorable conditions to the El-Burullus harbor entrance.  相似文献   

12.
Assessment of petroleum hydrocarbon (PHC) in the Chilika Lagoon, India, revealed a significant spatio-temporal variation in surface water (analysis of variance: n?=?120, p?相似文献   

13.
The speciation of trace metals in surface sediment in Kisumu Carwash area of Winam Gulf, was studied and results compared with those found at Usoma beach which was found to be several orders of magnitude less polluted. High proportions of the metals were bioavailable (fractions 1–6) with BA% ranging from 21.7% (Al) to 94.5% (Pb) at Carwash and 19.6% (Al) to ~100% (for Cd and Pb) at Usoma beach. The readily mobilizable fraction (fractions 1–4) decreased in the order: Pb > Mn > Sn > Cu > Co > Zn > Mg > Cd > Mo > Ni > Cr > Fe > Al at Carwash and Mn > Mo > Sn > Pb > Cd > Mg > Cu > Zn > Co > Ni > Fe > Cr > Al at Usoma beach. The total Zn, Cd, Cr, and Cu sediment concentrations at Carwash were higher than the threshold effect concentrations (TECs), although their bioavailable concentrations were lower than these limits. Both the total and bioavailable concentrations of Pb in surface sediment at Kisumu Carwash area were higher than the TEC threshold limit indicating significant contamination from this heavy metal. Although there was a general good agreement on data obtained by sequential extraction as compared with those obtained by direct aqua-regia digestion, there were large discrepancies for some specific metal analytes which could be accounted for in terms of analytical variations and lack of uniformity in physical and chemical composition of the sediment samples analyzed.  相似文献   

14.
• Sediment desiccation alters morphological characteristics of aquatic sediment. • Alternation in morphological properties of sediment limiting root characteristics. • Fibrous-rooted macrophytes root properties extra favor nutrients removal. • Thick-rooted macrophytes exhibit higher life-span in two sediment types. Purpose of the current study was to investigate the effects of constantly wet and dried-rewetted sediments on root functional traits of emerged macrophytes and their nutrients removal abilities. It is based on the hypothesis that root characteristics and nutrients removal abilities of plants will be altered in the course of sediment desiccation. Four emerged macrophytes including two fibrous-root plants (Canna indica and Acorus calamus) and two thick-root plants (Alocasia cucullata and Aglaonema commutatum) were investigated for their root functional traits and rhizoperformance in both wet and dried-rewetted sediments. Results showed that sediment desiccation followed by rewetting substantially altered the root functional traits (root surface area, radial oxygen loss, and root activity) of plants due to adverse changes in morphological characteristics (porosity, bulk density, particle density) of dried-rewetted sediments than by wet sediments. Consequently, limited plants growth and removal of nitrogen (N), phosphorus (P) and dissolved organic carbon (DOC) were recorded in dried-rewetted sediments and their pore water than in wet sediments. Radial oxygen loss from plant roots correlated positively with root functional traits, plants growth, and removal of N, P and DOC from pore water and sediment in both sediment types. Among the macrophyte species, the fibrous-root plants having advantages root functional traits, greatly influenced the rhizospheric conditions (pH, dissolved oxygen and redox potential), and demonstrated higher N, P and DOC reduction from both sediment types. While, the thick-rooted plants with thick diameter roots (D > 1 mm) and higher rhizome exhibited longer life-span in both sediment types.  相似文献   

15.
• The total organic pollutant concentrations in sediment were 27.4-1620 ng/g. • The phenol concentrations were relatively high in the sediment of the Dianchi Lake. • Average total concentrations decreased as follows: Caohai>Waihai>Haigeng Dam. • 1,4-dichlorobenzene, 3- or 4-methylphenol, 1,2,4-trichlorobenzene might be risks. Organic pollutants are widespread environmental pollutants with high toxicity, persistence, and bioaccumulation. Our aim was to investigate the distribution of aromatic amines, phenols, chlorobenzenes, and naphthalenes in the surface sediment of the Dianchi Lake, China. Nineteen surface sediment samples were collected from the Dianchi Lake, and 40 types of organic pollutants were analyzed via gas chromatography–mass spectrometry. The total organic pollutant concentrations in the surface sediment of the Dianchi Lake varied from 27.4 to 1.62 × 103 ng/g. The concentrations of phenols were much higher than those in other water bodies but still within a controllable range, whereas the concentrations of the other organic pollutant classes were similar or even lower. The detection ratio of 3- or 4-methylphenol was the highest (100.00%) among the pollutants. The average total organic pollutant concentrations decreased in the following order: Caohai (540 ng/g)>the middle of Waihai (488 ng/g)>the edge of Waihai (351 ng/g)>Haigeng Dam (90.4 ng/g). Pearson analysis showed a strong correlation among 1-methylnaphthalene, 2-methylnaphthalene, 1,3-dinitronaphthalene, and 1,4-dinitronaphthalene (p<0.01). Caohai, the north lakeshore of Waihai and the south of Waihai showed higher risk because of high concentration; meanwhile, 1,4-dichlorobenzene, 3- or 4-methylphenol and 1,2,4-trichlorobenzene were more likely to cause risks.  相似文献   

16.
本文以大沽排污河口表层沉积物为研究对象,分别运用ERL/ERM和生态危害指数两种评价方法对沉积物中6种重金属的潜在生物毒性风险进行评价,并对两种方法的评价结果进行对比。经均一化处理,重金属的含量均值由大到小的顺序排列为铬(168 mg/kg)〉锌(157 mg/kg)〉镍(60.7 mg/kg)〉铜(45.3 mg/kg)〉铅(7.31 mg/kg)〉镉(0.215 mg/kg)。经计算20个采样断面的沉积物中重金属毒性单位总和均在3~4之间,有80%的采样断面沉积物中重金属毒性单位总和大于3.5,毒性单位总和最大值为3.789。说明大沽排污河口沉积物中重金属的潜在生物毒性水平较低,可视为无生物毒性。  相似文献   

17.
攀枝花市水系沉积物与土壤中重金属的地球化学特征比较   总被引:4,自引:0,他引:4  
水系沉积物和土壤都是表生作用的产物,是环境中污染物质的重要受纳体,但两者在物质来源和受纳污染物方面又有不同。重金属通过不同方式进入到水系沉积物和土壤之中产生污染,对于区域环境具有重要的影响。为了了解攀枝花市水系沉积物和土壤中重金属元素地球化学特征的异同和污染状况,在攀枝花市范围内系统采集了水系沉积物和土壤样品,从环境地球化学角度,应用地球化学方法研究了攀枝花市水系沉积物及土壤中重金属的地球化学特征,应用地质累积指数法评价了污染情况,并对二者进行了比较研究。结果表明,攀枝花市水系沉积物中重金属的含量普遍高于土壤;水系沉积物和土壤中重金属的分布具有相似的特征;水系沉积物中重金属的污染程度高于土壤,但总体上来说,重金属的污染程度较小。两者的污染程度不同是因为接受污染物的方式不同;两者的分布趋势相同,说明具有相同或相近的污染来源。  相似文献   

18.
Concentrations of the heavy metals Cu, Ni, Pb, Zn, Cd, and Cr were examined in surface water and sediment from the Luan River inChina,. With a decline in Cu and Ni concentration found in surface water at downstream stations. This finding suggests that water currents are a major explanatory factor in heavy metal contamination. The abundance of Cr, Pb, and Cd observed in the middle reaches of the river indicates heavy metal contamination in local areas, although there was an obvious decrease in concentrations in the water downstream of the Daheiting Reservoir. The significant rising trend in Cu, Pb, and Ni seen the sediment farther away from the river also suggests that anthropogenic activities contribute to heavy metal pollution Sediments were therefore used as environmental indicators, with sediment assessment was conducted using the geo-accumulation index (Igeo) and the potential ecological risk index (RI). The Igeo values revealed that Cd (3.13) and Cr (2.39) had accumulated significantly in the Luan River. The RI values for most (89%) of the sampling stations were higher than 300, suggesting that sediment from the Luan River poses a severe ecological risk, with the potential ecological risks downstream higher than that in the upper and middle streams. Good correlations among Pb/Ni, Pb/Cd, Cu/Pb, and Cu/Cd in the water and Cr/Ni in the sediment were observed. Cluster analysis suggested that Cd may have various origins, being derived from anthropogenic sources.  相似文献   

19.
张霖琳  梁宵  魏复盛 《环境化学》2012,31(7):945-951
采用ICP-MS法测定汀江某河段底泥样品中重金属的含量,了解该地区13种元素的分布特征,通过地积累指数法和潜在生态危害指数法对底泥重金属污染进行综合评价.结果表明,用ICP-MS测定重金属快速、简便、结果准确,地积累指数法得出13种元素污染程度由强至弱依次为Cd>Cu>As>Se>U>Co=Zn>Pb>Mn>Th>Ni=Tl>Cr,生态危害指数法得出6种重金属对样品所在区域造成的潜在生态危害,由强到弱依次为Cd>Cu>As>Pb>Zn>Cr,Cd、Cu和As为该地区的主要污染因子.其中3#点位RI值为1283,提示生态危害程度很强、污染程度最高,2#点位其次,1#点位也存在一定污染.  相似文献   

20.
Although use of pesticides is critical in agricultural production, their residues present a potential risk to non-target organisms and lower the quality of surface water. In Kenya for instance, widespread use of pesticides in the catchment of Lake Naivasha, has raised concern over the years due to possible pollution of the lake through discharge of runoff from agricultural fields. In this study, sediment, water, and fish samples were analyzed for selected pesticide residue contamination. Chlorpyrifos-ethyl (CPF) was detected in the range of 2.6–24.9 ng/ml and 6.8–35.8 ng/g dry weight (dw) in water and sediment, respectively. Meanwhile, diazinon was detected in the range of below detection limit (bdl) to 33.3 ng/ml and bdl to 9.3 ng/g dw in water and sediment, respectively. CPF was detected in fish tissues (Niloticus leucosticus) in the range of bdl to 8.9 ng/g dw with diazinon and carbofuran not detected in any fish sample. A significant difference was observed between different seasons with wet season recording higher levels. Concentrations detected varied seasonally and on average exceeded the maximum criterion set by European Union. Therefore, data generated in this study are useful in environmental risk assessment and as a baseline in formulation of mitigation measures to protect the lake from pesticides residues pollution.  相似文献   

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