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1.
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       下载免费PDF全文
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   

2.
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   

3.
为了解巢湖湖区及主要出入湖河流沉积物中重金属的污染特征,对表层沉积物中重金属元素含量进行分析,基于地积累指数法、潜在生态风险指数法和沉积物质量基准法对沉积物污染风险进行评价,并对沉积物重金属来源进行初步分析.结果表明,河流沉积物中重金属的平均含量显著高于湖区,是湖区沉积物重金属含量的1.18~5.15倍,其中南淝河Cu、Zn、Pb、As和Hg含量较高,分别是背景值的3.53、16.98、3.98、5.84和23.11倍,西半湖Cu、Zn、Pb、Cd和Hg平均含量要高于东半湖,是全湖平均的1.04~1.45倍.地积累指数法和Hkanson潜在生态风险指数法评价结果均表明,Cd和Hg是主要的生态风险贡献因子,在所调查的表层沉积物中Cd和Hg数值分别为43.17~3870.94和29.96~924.57,已处于较大风险数值.此外,源分析结果表明,巢湖湖区及主要出入湖河流表层沉积物中Cu、Zn、Pb、Cr、Hg和As相关性显著,具有相似的来源,可能来自于工业废水与生活污水.  相似文献   

4.
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   

5.
武汉典型湖泊沉积物中重金属累积特征及其环境风险   总被引:20,自引:1,他引:19  
采集武汉市8个典型湖泊的表层沉积物,分析11种重金属的含量及其不同形态组成,研究了不同湖泊金属元素的富集与污染程度,探讨了沉积物中重金属的污染来源及其潜在生态风险,结果表明,沉积物中重金属Cd累积最严重,Zn和Hg也发生明显累积,龙阳湖污染较重,南太子湖和墨水湖污染中等,其它湖泊污染总体较轻.沉积物性质对重金属累积的影响不显著,城市工业活动强烈影响着重金属的分布,不同重金属的形态分布差异较大,Cd生物可利用态含量最高,其次为Mn、Zn、Co、Cu和Pb;而Sb和Hg以残留态占绝对优势,生态风险较小,相关分析和主成分分析表明,化石燃料燃烧、金属冶炼等是武汉市湖泊沉积物中重金属来源的主要贡献者,同时岩石风化等地球化学过程也影响着重金属的污染.  相似文献   

6.
为评估滆湖围网拆除工程实施效果,采用高密度网格化布点方法,系统分析滆湖沉积物营养盐和重金属的空间分布和污染特征;并基于有机氮评价方法、综合污染指数评价方法、重金属地质累积指数法和重金属潜在生态风险评价方法进行污染风险评价.结果表明,滆湖沉积物总氮(TN)、总磷(TP)和总有机碳(TOC)的平均含量分别为(3709±1004)mg/kg、(1127±650) mg/kg和(78.39±23.88) mg/g,三者空间分布特征较为一致;营养盐综合污染指数评价表明,全湖整体为重度污染,其中全湖TN均处于重度污染状态,TP绝大部分区域也处于重度污染状态.沉积物重金属Zn、Cr、As、Pb、Ni、Cu、Cd 的平均含量分别为(170.62±47.25)、(105.18±34.91)、(68.55±10.86)、(52.43±14.73)、(44.04±11.93)、(42.57±12.43)、(1.55±1.06) mg/kg,整体上呈现出由南向北、自西向东逐渐增加的趋势,重金属含量最高值在湖区东北角;地积累指数法和潜在生态风险指数法评价结果均表明Cd和As是主要的生态风险贡献因子,其中Cr和Ni的污染程度表现为清洁,Cr、Ni、Cu、Zn和Pb的单项潜在生态风险等级表现为轻微风险.与围网拆除前比,湖中区西南部沉积物营养盐含量无显著变化,湖南区南部沉积物营养盐状况明显改善,但其余各区域沉积物营养盐状况均有不同程度的恶化;湖区沉积物中重金属元素平均含量均有极大程度的降低,降幅在29.50%~80.45%之间,表明在外源污染输入得到一定控制时,围网拆除在控氮、控磷效果及改善重金属污染状况方面有着积极作用.  相似文献   

7.
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   

8.
巢湖蓝藻聚集对重金属迁移释放的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
江江  李玉成  王宁  张学胜 《湖泊科学》2017,29(3):558-566
以巢湖蓝藻水华聚集地西半湖表层沉积物与蓝藻为对象,研究了表层沉积物重金属(Cd、Cr、Cu、Zn、Pb、Ni和Mn)总量的分布特征.同时,利用BCR连续提取法对沉积物中重金属Cd和Mn的形态进行分析,模拟探究蓝藻腐殖化过程中重金属含量的变化,探讨了蓝藻腐殖化对重金属吸附-释放的影响.结果表明,各采样点表层沉积物重金属含量均不同程度超出背景值,且距离南淝河越近越突出.潜在迁移指数表明整个西半湖沉积物中重金属Cd比Mn更易形成二次污染.相关性分析显示重金属Cd和Mn各形态含量和总量之间均表现出极显著正相关.巢湖西半湖属于典型的藻型湖,Cd和Mn的来源和分布均与蓝藻聚集密切相关,结合实验室模拟蓝藻腐殖化过程对重金属的吸附-释放规律,认为蓝藻腐殖化过程会对Cd和Mn的迁移释放产生影响.  相似文献   

9.
太湖流域西氿湖沉积岩芯中重金属污染及潜在生态风险   总被引:5,自引:1,他引:4  
通过对太湖流域西沈湖沉积物岩芯XJ2中Cu、Pb、Zn、Cd、Cr等5种重金属元素总量的分析,结合测年结果,揭示了不同时间段重金属污染物的分布特征,并利用Hakansen潜在生态风险评价法对沉积物岩芯的污染状况及潜在生态风险的历史变化进行了研究.结果表明岩芯受Cd元素污染最重,其它4种元素较Cd则轻得多,因此Cd元素是影响该地区沉积物潜在生态风险的绝对主导因素.从20世纪初叶开始,沉积物中的重金属元素污染及其相应的潜在生态风险开始上升,并且上升幅度不断加剧,到20世纪90年代达到最大值,沉积物污染及潜在生态风险级别均为"很高",随后便开始迅速下降,然而直到2004年这两个参数仍然维持在"很高"级别.  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.
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   

12.
In this paper, the vertical variations of heavy metal elements (including Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) in the sediments of Songhua Lake are analyzed using sediment cores. A 70‐year evolutionary history of these heavy metal elements in Songhua Lake is described and the sources of the heavy metals in the sediments are investigated by evaluating the pollution characteristics of the metals in terms of their enrichment coefficients and geoaccumulation indexes. The results indicate that Cr, Cu, Mn, Ni, Pb, and Zn in the sediments originated mainly from basin erosion and were transported to the lake by rivers. Cd and Hg in the sediments also originated from basin erosion that occurred prior to the mid‐1990s, and these sediments have since been overlaid by artificial pollution. The distribution of heavy metals in the sediments of Songhua Lake is influenced by many factors, including sediment composition, the relative importance of fluvial input, and artificial pollution.  相似文献   

13.
Five sediment zones(20 samples) were collected in Mighan Lake,near Arak city in Markazi province,and were analyzed to reveal element sources and assess the quality of metal contamination.Both anthropogenic and natural origins were identified by correlation,factor,and cluster analyse.According to the enrichment factors(EF) of trace metals(Ba,Co,Cr,Cu,Ni,Pb,Rb,Sr,Zr,and Zn),three groups were identified.Enriched trace elements included:Ni,Zn,and Sr.Comparisons with contamination degree and benchmark sediment quality criteria and guidelines showed that Mighan Lake has potential for adverse effects on aquatic biota because of Ni,Zn,and Cr.  相似文献   

14.
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   

15.
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   

16.
洞庭湖沉积物中重金属污染特征与评价   总被引:31,自引:2,他引:29       下载免费PDF全文
于2003-2004年在洞庭湖湖区采集沉积物样品700个,测定了沉积物中As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的含量,并用地积累指数方法和主成分分析法对沉积物中的重金属污染状况进行了评价和分析.结果显示,洞庭湖各子湖区沉积物中Cd、Cr、Cu、Pb、zn的平均含量都属于国家土壤二级标准,AB、Hg、Ni属于国家土壤一级至二级土壤标准;在南洞庭湖与东洞庭湖人湖河流的三角洲的前缘是沉积物重金属积累最高的地点,而在西洞庭湖入湖河流三角洲的后缘沉积物重金属含量比前缘高.采用综合地积累指数法对洞庭湖各子湖区沉积物进行评价,结果表明:南洞庭湖(重污染)>东洞庭湖(偏重污染)>西洞庭湖(中度污染)>大通湖(中度污染)>城陵矶(轻度污染).采用主成分分析法对洞庭湖各子湖区沉积物进行分析,结果表明:南洞庭湖与东洞庭溯第一主成分贡献率分别为55.22%、56.86%,主要支配AS、Cd、Hg、Pb、zn的载荷,而第二主成分贡献率分别为30.04%、33.11%主要支配Cu、Cr、Ni的载荷:西洞庭湖、大通湖和城陵矶因沉积物重金属来源不同,主成分分析结果相差较大.  相似文献   

17.
Surface sediment samples collected from the inner shelf region of the Bay of Bengal, were analysed for the major elements and total and acetic acid available trace elements (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Si, Zn) to evaluate geochemical processes influencing their distribution. Major elemental analysis showed that the sediments had high concentrations of Si and relatively low concentrations of Al and Fe. Both major elemental and trace metal concentrations indicated that the sediments represent weathered products of granite and charnockite. Normalization of metals to Al indicated relatively high enrichment factors for Pb, Cd, Zn and Cr. The higher proportions of nondetrital Pb (66%), Cd (41%) and Co (28%) reveal metal contamination due to anthropogenic inputs. Factor analysis (FA) identified six possible types of sedimentological and geochemical associations. The dominant factor accounting for 26.9% of the total variance identifies an anthropogenic input and accumulation of nondetrital Cd, Co, Cr, Ni and Pb. Association of these metals with CaCO3 reveals that shell fragments in the surface sediments are likely act as a carrier phase for nondetrital metals. The results are discussed in the context of the sources and pathways of elements in the Bay of Bengal.  相似文献   

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