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1.
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   

2.
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   

3.
武汉东湖沉积物中重金属生物有效性研究   总被引:6,自引:0,他引:6  
郑利  徐小清  金利娜 《湖泊科学》2003,15(4):319-325
沉积物中的酸挥发性硫化物(AVS)是预测厌氧沉积物中重金属生物有效性的重要参数,SEM/AVS大于1时沉积物中重金属具有潜在生物毒性,小于1时则无生物有效性. 本文研究了东湖三个不同污染负荷的站点的同步提取金属SEM(Cu, Zn, Pb, Cd, Ni, Co, Ag, Cr)和SEM/AVS的深度分布,研究表明东湖沉积物中主要重金属是Zn, Cr和Cu,约占SEM总量的90%. I站、II站沉积物中AVS是重金属生物有效性的主控因子之一,对重金属的深度分布影响较大,重金属不具有生物有效性;III站沉积物中AVS对重金属的深度分布影响较小,重金属具有潜在的生物毒性. 相关分析表明,I站、II站沉积物中Cr、Ni、Ag、Cd与AVS在P<0.05有显著性相关,AVS对这些金属的深度分布具有更强的控制作用;虽然两站沉积物中Cr的含量差别不大,东湖I站沉积物中Cr/AVS比值(0.02)显著高于II站(0.003),沉积物中Cr与硫化物的结合主要是受还原反应的影响.  相似文献   

4.
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   

5.
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   

6.
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   

7.
太湖沿岸区浅层底泥重金属污染分析及生态风险评价   总被引:2,自引:0,他引:2  
近年来太湖底泥重金属污染越来越受到各方关注.为了解太湖沿岸区底泥重金属污染状况,基于2018年太湖全湖污染底泥勘察项目中重金属监测数据,对梅梁湖、竺山湖、西部沿岸区、南部沿岸区、东太湖、贡湖6个太湖沿岸湖区浅层(0~30 cm深度区间)底泥中Hg、Cd、As、Pb、Cu、Zn、Cr、Ni 8种重金属元素含量进行分析,运...  相似文献   

8.
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   

9.
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   

10.
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   

11.
洞庭湖流域对湘江湖南段6个城市江段铜锈环棱螺(Bellamya aeruginosa)腹足和内脏团的As、Cd、Pb、Cu、Zn、Cr富集量进行分析,运用单因子污染指数法评价其受污染程度,并分别采用平均每周/每月摄入量法和目标危害系数法对其膳食风险进行评估,旨在为湘江流域居民铜锈环棱螺的消费安全提供参考.结果显示,铜锈环棱螺腹足As、Cd、Pb、Cu和Zn的富集量均值分别为0.92、1.65、0.90、13.01和67.62 mg/kg,Cr未检出,As、Cd、Pb和Cu的超标率分别为87.06%、27.06%、24.72%和2.35%.内脏团As、Cd、Pb、Cu、Zn和Cr的富集量均值分别为9.61、3.21、3.75、33.58、169.05和1.23 mg/kg,As、Cd、Pb、Cu和Cr超标率分别为100%、71.76%、65.88%、14.12%和75.8%.所有江段成人As、Cu和Zn的每周摄入量均值和最高值均低于FAO/WHO食品添加剂联合专家委员会(JECFA)提出的暂定每周耐受摄入量参考值(PTWI),但株洲成人Cd的每月摄入量均值超过其每月耐受摄入量参考值,且最大值是其参考值的3.44倍,永州、湘潭地区成人Cd的每月摄入量最大值也分别是其参考值的1.16和1.68倍.所有江段铜锈环棱螺摄入的单一重金属健康风险值除As外均小于1,但多种重金属复合暴露健康风险值均接近或大于1.结果表明,湘江湖南段6个城市江段铜锈环棱螺均受到一定程度的污染,其中衡阳、湘潭和株洲江段较为严重,且各江段铜锈环棱螺内脏团重金属富集量整体上均高于腹足,故当地居民长期食用后存在潜在的健康风险.  相似文献   

12.
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   

13.
In order to investigate the pollution levels, sources and ecological risks of arsenic (As) and heavy metals (Cr, Ni, Cu, Zn, Pb and Cd) in inshore sediments of the Yellow River estuary, the surface sediment in areas of inshore coastal waters were sampled in October 2014 as the flow-sediment regulation project (FSRP) was implemented for 13 years. Results showed that the concentrations of As and heavy metals in inshore sediments of the Yellow River estuary were in the order of Zn?>?Cr?>?Cu?>?Ni?>?Pb?>?As?>?Cd. Higher levels of As, Cr, Ni, Cu, Zn and Pb generally occurred in fine-grained sediments of the Yellow River estuary and the southeast region, which was consistent with the spatial distribution of clay. In contrast, higher concentrations of Cd were generally observed in northwest area of the Yellow River estuary and near the Qingshuigou estuary, which showed similarly spatial distribution with that of sand. The sediment quality guidelines (SQGS) and geoaccumulation indices (Igeo) indicated that the inshore sediments were polluted by Cu, Cd, As, Pb and Zn, and, among them, Cd pollution was more serious. Ecological risk indices (E r i ) demonstrated low risks for Cr, Ni, Cu, Zn, Pb and As, and high potential toxicity by Cd. The integrated ecological risk index implied that 6.8% of stations presented moderate risk, 4.5% of stations exhibited disastrous risk, and 88.7% of stations demonstrated considerable risk. Principal component analysis indicated that Ni, Cu, Zn, Pb and As might originate from common pollution sources, while Cr and Cd might share another similar sources. With the continuous implementation of FSRP, As and heavy metal levels in inshore sediments of the Yellow River estuary could be classified as stage I (2002–2010) and stage II (2010–2014). In the stage I, As, Cr, Ni, Cu, Zn and Pb levels fluctuated but decreased significantly, whereas Cd concentrations showed little variation. In the stage II, As and heavy metal levels significantly increased although some little fluctuations occurred. The continuous accumulation of As and heavy metals (especially for Cd) in inshore sediments of the Yellow River estuary would occur again as the FSRP was implemented for 9 years (since 2010). The ecotoxicological risk of Cd, As, Ni and Cu in inshore sediments might be more serious since the accumulation of the four elements would be continuously occurred in future years. Next step, there will be long-term potential consequences for marine organism if effective measures are not taken to control the loadings of metal pollutants into estuary.  相似文献   

14.
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   

15.
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   

16.
Surface sediments in the Xiaoqinghe estuary, southwestern coastal Laizhou Bay, were examined to assess the bio-toxic risk of heavy metals (Cd, Cu, Ni, Pb and Zn) with the effects range-low and effects range-median guidelines (ERL–ERMs) and the concentration ratio of simultaneously extractable metals to acid volatile sulfides ([SEM]/[AVS]). Based on the ERL–ERM guidelines, bio-toxic effect caused by Cu, Ni, Pb and Zn could be expected in the riverine surface sediments of the Xiaoqinghe estuary; and the surface sediments in the marine area were in good quality and only Ni might cause bio-toxic effect occasionally. The AVS–SEM guidelines revealed that no bio-toxic effect could be caused by any of the studied metals in both the riverine and marine sediments, since there were excess sulfides in surface sediments which could form water-insoluble substances with free metal ions and reduce the bioavailability of heavy metals.  相似文献   

17.
太湖浮游植物中重金属含量的季节变化特征及湖区差异   总被引:4,自引:2,他引:2  
近年来随着社会经济的发展,排入太湖的污水中重金属含量不断增加,为研究太湖浮游植物中重金属的污染状况,分别于2009年春季(4月)、夏季(7月)和冬季(12月)对太湖不同湖区展开调查,通过HCA聚类分析和Pearson相关分析探讨不同湖区浮游植物中重金属含量的季节变化,并与优势藻种进行CCA分析,对浮游植物重金属与各藻种关系进行初步探讨.结果表明:太湖浮游植物中重金属的含量大小为:ZnMnPbCuNiCrAsCdHg,其中Zn、Cu、Mn、Pb、Ni的季节变化明显,Zn和Cu、Pb、Ni、Cr之间的相关系数很高且具有同源性.通过对比不同湖区,发现北部梅梁湾的浮游植物重金属含量较高,东太湖和湖心区含量均低于沿岸湖区.CCA分析表明春季重金属与优势藻种呈正相关,而夏季和冬季二者呈负相关.三季中重金属与蓝藻和绿藻的相关性最高,与隐藻的相关性最低.蓝藻中,重金属与铜绿微囊藻的相关性高于水华微囊藻.  相似文献   

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