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1.
Spatial distribution and contamination assessment of heavy metals in urban topsoil from inside the Xi’an second ringroad, NW China 总被引：1，自引：1，他引：0
The paper reports the spatial distribution and contamination level of heavy metals (Co, Cr, Cu, Mn, Ni, Pb, Zn and V) in urban topsoil from the interior area of the second ringroad of Xi’an city, China, based on X-ray fluorescence spectroscopy measurements. Geostatistical analysis shows that Co, Cu, and Pb have similar spatial distribution patterns. Heavy traffic density mainly contributed to the high concentrations of Co, Cu and Pb. The spatial distribution of Cr coincides with the industrial activity, whereas the spatial distribution of Zn differs from other heavy metals. The high concentrations of Zn coincide with heavy traffic and high population density. For Mn, Ni and V, natural factors are important in controlling their distribution. The calculated geoaccumulation indices indicate that urban topsoil inside the Xi’an second ringroad was uncontaminated by Cr, V, Mn and Ni, while Pb, Cu, Co and Zn are classified as uncontaminated to moderately contaminated with means of 0.64, 0.46, 0.26 and 0.21, respectively. The Nemero synthesis pollution index of these heavy metals revealed that the topsoil inside Xi’an second ringroad has been heavily contaminated due to anthropogenic activity. 相似文献
2.
固体聚合膜电解浓集法是浓缩氚含量较低(1 Bq/m~3)的天然水样的常用方法,但因水样自身含有杂质离子或电解装置聚合膜带入杂质进入浓集液,使浓集液偏酸性,在测量过程中易产生化学淬灭效应,导致氚的测量值偏低。本文研究了水样自身存在的杂质离子和聚合膜上残留的杂质离子、样品溶液的pH值及其电导率所产生的化学淬灭效应的影响,实验表明,为减少化学淬灭效应,提高测量低含量氚的准确性,需保证水样溶液呈中性,电导率≤1μS/cm,同时避免杂质沉积在聚合膜上。如果水样溶液的pH值偏酸性、电导率大于1μS/cm,可采用酸碱混合型离子交换树脂去除水样中自身的杂质;对于聚合膜引入的杂质,可在电解后的水样中加入微量氨水将其pH值调节至中性。 相似文献
3.
包头市典型工业区表层土壤中重金属污染状况及其潜在生态风险研究 总被引：3，自引：3，他引：0
为了解包头市典型工业企业对其所在地土壤中重金属含量的影响及污染现状,利用相关性系数对其表层土壤中7种重金属(Cu、Zn、Pb、Cr、Cd、Mn、Ni)来源进行研究,并采用内梅罗综合污染指数法和潜在生态危害指数对其污染状况进行评价。结果表明,7种重金属含量平均值均高于内蒙古土壤背景值,其中Cd、Mn、Ni超标率已达100%,而Cu、Pb、Zn的超标率分别为97%、93%和93%,只有Cr超标率较低(53%),污染程度依次为CdPbCuNiZnMnCr,其中Pb和Cd为重度污染,Cu、Zn、Ni为中度污染,Cr、Mn为轻度污染;Cu、Zn、Cr、Mn、Ni可能同时来自工业生产和交通运输两个源,而Pb和Cd除上述来源外,燃煤烟气的排放有较大贡献。潜在生态危害依次为CdPbCuNiCrZnMn,其中Cd的潜在生态风险最大,应予以高度重视,其他金属的风险均为轻微。 相似文献
4.
An investigation on spatial distribution, possible pollution sources, and affecting factors of heavy metals in the urban–suburban
soils of Lishui city (China) was conducted using geographic information system (GIS) technique and multivariate statistics.
The results indicated that the topsoils in urban and suburban areas were enriched with metals, such as Cd, Cu, Pb, and Zn.
Spatial distribution maps of heavy metal contents, based on geostatistical analysis and GIS mapping, indicated that Cd, Cr,
Cu, Mn, Ni, Pb, and Zn had similar patterns of spatial distribution. Their hot-spot areas were mainly concentrated in the
densely populated old urban area of the city. Multivariate statistical analysis (correlation analysis, principal component
analysis, and clustering analysis) showed distinctly different associations among the studied metals, suggesting that Cr,
Cu, Ni, Pb, Cd, and Zn had anthropogenic sources, whereas Co and V were associated with parent materials and therefore had
natural sources. The Cd, Cr, Ni, Pb, and Zn contents were positively correlated with soil organic matter, pH, and sand content
(p < 0.01). It is concluded that GIS and multivariate statistical methods can be used to identify hot-spot areas and potential
sources of heavy metals, and assess soil environment quality in urban–suburban areas. 相似文献
5.
为了解大亚湾表层沉积物中重金属的污染状况,对大亚湾海域23个点位表层沉积物中7种重金属元素（Cr、Ni、Cu、Pb、Zn、Cd、As）的质量分数、形态特征、来源控制因素以及潜在生态风险进行了研究。采用优化BCR提取法分析重金属元素赋存形态,并依据各种重金属元素的形态特征与沉积物基质属性进行了相关因子分析,了解其分布的控制因素。结果表明：大亚湾沉积物重金属元素呈现环带状分布特征,从岸向湾内逐渐减小;重金属元素质量分数的高值区主要分布于大鹏澳、哑铃湾及范和港附近;重金属元素赋存形态中Cr、Ni、Cu、Zn、As主要以残渣态存在,Pb主要以可还原态存在,Cd主要以酸提取态存在;7种重金属元素各自非残渣态所占比率从大到小为Pb(78.83%)、Cd(78.65%)、Cu(48.54%)、Zn(48.10%)、Ni(38.31%)、Cr(28.43%)、As(27.76%),即Pb最高,As最低,表明Pb的迁移性最强;通过因子分析,大亚湾重金属主要为沿岸自然风化产物的输入,其次为工业废水及养殖污水。运用酸提取态风险评估法对重金属元素潜在生态风险进行评价,发现研究区所选重金属元素综合风险评价Cd为高风险,其余重金属为中-低风险等级。 相似文献
6.
Assessment of heavy metal pollution in urban topsoils from the metropolitan area of Mexico City 总被引：2，自引：0，他引：2
O. Morton-Bermea E. Hernández-Álvarez G. González-Hernández F. Romero R. Lozano L.E. Beramendi-Orosco 《Journal of Geochemical Exploration》2009
This study reports the degree of heavy metal pollution (Cr, Cu, Ni, Pb, Zn and V) in 135 urban topsoil samples from the metropolitan area of Mexico City. Pollution indices (PI) were calculated to identify the metal accumulation with respect to the background values. The levels of heavy metals in the analyzed samples show a wide range of variation. Lead, Zn and Cu are the elements most enriched in the analyzed area, presenting pollution indexes of up to 23.8, 21.6 and 12.4, respectively. Geochemical maps were produced to assess the spatial distribution of pollution index. It is concluded that emissions from vehicles may be the major source of Pb urban contamination; furthermore, other small or large factories are possible sources for soil pollution (Cu, Zn). The concentration of Cr, Ni, and V in most of the analyzed samples do not appear to reach pollution levels. The assessment of the soil environmental quality in the metropolitan area Mexico City in terms of PI can be used as the basis for a regular monitoring program for implementing suitable pollution control measures. 相似文献
7.
以上海市中心城区为例,探讨路面径流重金属在颗粒物-水相间的分配特征及其影响因素.研究表明,路面径流Cr的25%分位数浓度值,以及Zn、Pb、Cd的90%分位数浓度值超出地表Ⅴ类水标准,Cu和Ni污染程度较轻.径流重金属Pb、Zn、Cu及Cd总量浓度与悬浮颗粒物(TSS)含量呈现较明显的正相关关系,Ni与TSS浓度相关性不显著.径流冲刷过程中Cu和Ni溶解态含量比例平均值为35%;Zn和Cr平均值为19%~22%;Cd和Pb溶解态比例最低,平均值为4%~8%.应用扣除残渣态后的颗粒物重金属含量计算固液分配系数依次为Pb>Cd>Zn>Ni>Cu>Cr.径流中悬浮颗粒物浓度与固液分配系数存在显著负相关关系,呈现明显的"颗粒物浓度效应",径流pH值在6.4~7.2区间时对固液分配系数影响相对较小. 相似文献
8.
滦河流域沉积物中重金属分布特征及风险评价 总被引：3，自引：0，他引：3
沉积物作为重金属污染物的源和汇,对水环境有着至关重要的影响.为了全面了解滦河沉积物中重金属污染现状,采用电感耦合等离子体质谱法对滦河干支流沉积物中重金属含量进行了测定,分析了其空间分布,并采用潜在生态危害指数法对滦河沉积物进行了评价.结果表明:滦河沉积物中Cr、Ni、Cu、Zn、Cd 和Pb的平均含量分别为60.40、26.15、48.07、76.42、0.30、25.55 mg/kg,其中Cu和Cd含量高于中国水系沉积物背景值.滦河干流的重金属含量空间分布自上游往下游呈逐渐增加趋势.潜在生态危害指数评价结果表明:不同重金属污染对滦河流域生态风险构成的危害由强至弱依次为:Cd＞Cu ＞Pb＞Cr＞ Zn,其中Cu、Pb、Cr和Zn为低生态危害等级,Cd以中等生态危害等级为主.总体上,滦河沉积物重金属处于中等生态危害等级,干流大黑汀水库和支流瀑河宽域处于强生态危害等级. 相似文献
9.
10.
河北省保定市平原区土壤重金属污染及潜在生态危害评价 总被引：1，自引：0，他引：1
以河北省保定市平原区土壤为对象,采用单因子指数法和尼梅罗综合指数法对土壤重金属的环境质量及污染特征进行评价,并采用Hakanson提出的潜在生态危害指数法对土壤中重金属的潜在生态危害进行评价。结果表明：重金属污染程度依次是Cd＞Zn＞Hg＞Cu＞Pb＞Cr＞Ni＞As,其中Cr、Pb、Ni、As都处于清洁安全状态,Hg和Cu绝大部分样点处于清洁安全状态,分别只有0.15%和0.40%处于警戒状态,Cd、Zn元素都出现污染,其中Cd面积最大,达到0.22%;综合污染评价土壤环境整体良好,清洁、安全、警戒、污染土壤面积比例分别为94.39%、5.00%、0.50%、0.11%,其中警戒及污染土壤面积为0.61%,其形成可能与工业生产及人类活动有关;各重金属元素中,产生潜在生态危害的重金属主要是Hg,已达到中等潜在生态危害水平,其余重金属均为轻度潜在生态危害,综合考虑多种重金属的潜在生态危害性,其轻微生态危害、中等生态危害、强生态危害、很强生态危害的百分比分别为93.71%、4.71%、1.29%、0.29%,整体表现为轻微潜在生态危害。 相似文献
11.
太湖MS岩芯重金属元素地球化学形态研究 总被引：21，自引：4，他引：17
采用BCR三步提取法对太湖MS岩芯沉积物中Cu、Fe、Mn、Ni、Pb和Zn等6种重金属元素的化学形态进行了研究.结果表明,有效结合态的Cu、Ni和Pb主要以有机物及硫化物结合态、Fe-Mn氧化物结合态存在,Fe和Zn主要以Fe-Mn氧化物结合态存在,Mn主要以可交换态及碳酸盐结合态存在;Fe-Mn氧化物结合态的Ni、Pb和Zn与可还原态的Mn有较好的正相关关系,有机物及硫化物结合态的Cu、Mn、Ni、Pb和Zn与有机碳含量有较好的正相关关系;重金属形态分布体现了重金属元素地球化学性质的差异,以及重金属形态含量与沉积物理化性质的关系.沉积岩芯重金属元素形态垂向变化规律及次生相富集系数表明,Cu、Mn、Ni、Pb和Zn在沉积岩芯13～4 cm有效结合态含量较稳定,为自然沉积;4～0 cm有效结合态含量明显升高,存在一定程度的人为污染.根据137Cs测年结果判断,沉积岩芯Cu、Mn、Ni、Pb和Zn等重金属污染开始于20世纪70年代末期,主要污染元素及污染历史与太湖流域污染工业类型及经济发展阶段相吻合. 相似文献
12.
为评价某城市规划新区表层土壤质量,利用网格法采集表层土样1000件,分析8种重金属(Cd、 Cu、 Zn、 Ni、Cr、Pb、Hg、As)元素的含量,并分别运用污染负荷指数(PLI)和潜在生态危害指数(RI)评价研究区表层土壤中重金属的污染程度和危害等级。利用克里金插值法研究土壤PLI和RI的空间分布特征。结果表明:研究区内表层土壤重金属平均值均大于中国土壤背景值,Cd、Cu、Ni较为富集。研究区Cd和Cu元素为重度污染,Cd的生态危害性较强,87.90%的土样为重金属轻微污染,60.83%的土样为中等生态危害。污染较为严重和风险较强的地区主要位于研究区西南部河流两岸,Cu和Cd可能受到了人类活动的影响而偏高。 相似文献
13.
为支撑雄安新区土地资源科学管理,完善中国土壤污染评价体系,文章以雄安新区某废旧金属冶炼区为研究区开展地质调查,采集541件表层土壤样品,测定了土壤中的Cd、Hg、Pb、As、Cu、Zn、Cr、Ni八种重金属元素的含量和pH,采用主成分分析法研究重金属元素的组合及分布特征,通过单因子指数法、内梅罗综合指数法、地质累积指数法、潜在生态风险评价法和人体健康风险评价法对土壤重金属的污染程度及风险进行评价。结果显示：研究区土壤中Cu、Zn、Cd、Pb元素超标主要受冶炼活动影响,As、Hg元素高值异常主要由受唐河污染的地下水灌溉引起;单因子污染指数超标比例大小顺序为Cd>As>Cu>Zn>Pb>Hg>Cr=Ni;内梅罗综合指数评价结果显示54%的样品达到了污染水平;地质累积指数超标比例大小为Cd>Cu>Pb>As>Zn>Hg>Ni>Cr,Cu、Cd、Zn、Pb、As极重污染比例分别为13.5%、10.2%、9.1%、10.9%、17.2%;Cd和Hg是主要的生态危害元素,Cd中等-强生态危害比例为65.2%,Hg中等-强生态危害比例为71.3%;非致癌风险因子主要为As、Cr、Pb,95.2%样品对儿童的非致癌风险超过了1,29件样品中As对儿童的致癌风险超过10-4,研究区土壤重金属对儿童具有较高的健康风险。 相似文献
14.
研究雄安地区土壤重金属和砷元素空间分布特征及其来源,对于支撑新区土地资源和环境管理具有重要意义。基于雄安新区土壤环境调查,运用地统计学方法和ArcGIS 技术分析模拟了土壤中As、Hg、Cd、Cu、Pb、Zn、Ni、Cr等8种元素空间分布特征,综合运用空间分析、多元统计学方法和正定因子矩阵模型解析这些元素的主要来源。结果表明:（1）区内土壤质量总体良好,4.35 %的土壤样品Cd和Cu含量超过农用地土壤污染风险筛选值,但均低于农用地土壤污染风险管控值;与河北省背景值相比,Cd、Cu、Pb、Zn和Hg存在不同程度中度和显著富集。（2）As、Cd、Cu、Pb、Zn、Ni、Cr含量呈现出由北部向南部逐渐增高的趋势,高值区主要分布在新区西南部;Hg元素分布分散,高值区主要分布在城镇及工业企业周边。（3）不同土地利用类型土壤剖面重金属和砷元素垂向分布受pH值、有机碳和铁铝氧化物等理化性质影响显著。（4）研究区土壤重金属和砷元素富集受人类活动影响明显,人为来源贡献率达67.12 %,Hg元素主要来源于人为排放的大气沉降富集,As元素富集受到废渣堆放和利用的影响,Cd、Cu、Pb和Zn元素富集受工业生产、污水灌溉以及尾气排放等活动影响。研究成果可为雄安新区合理制定土地资源开发利用和生态保护措施提供技术支撑。 相似文献
15.
湖南水口山及周边是湖南省重金属污染较为严重的地区之一,龙王山金矿床是该区中部的一个重要金矿床.为调查该矿床废石堆污染状况、是否为周边环境的污染源、污染途径、重金属迁移能力和潜在的危害,对矿区FS17废石堆进行了自然淋滤水和24 m浅钻系统取样,开展重金属元素总量分析,利用单因子指数法和内梅罗综合污染指数法对其重金属污染程度进行污染评价,采用四步改良BCR提取法分析废石堆中8种重（类）金属元素（Pb、Zn、Cd、Cu、Cr、Ni、As和Fe）的赋存形态,并利用迁移指数量化废石堆重金属元素迁移能力;发现废石堆中Cd、Cu、Pb、As、Zn、Ni重金属元素严重超标,且在垂向上分布极不均匀;其自然淋滤水样中重金属元素Cd、Ni、Zn、Cu也严重超标;废石堆浅层重金属元素潜在迁移能力顺序为:Cd＞Ni≈Zn＞Cu＞Pb＞As＞Cr＞Fe,深层重金属元素迁移能力顺序为:Cd＞Zn＞Cu＞Ni＞Cr＞Pb＞As＞Fe,浅层重金属元素的迁移性大于深层;说明该废石堆重金属元素含量高,是周围环境重要污染源,酸性废水排放为其释放污染元素的主要途径;Cd、Cu、Zn、Ni迁移能力强,是周围环境的主要污染元素;Pb、Ni、As的迁移性在深层明显降低,可以通过埋深来削弱其迁移性,而Cr不会对周边环境产生污染. 相似文献
16.
Distribution and speciation of heavy metals in surface sediments from the Yangtze estuary and coastal areas 总被引：3，自引：2，他引：1
Xue Li Ying Wang Baohua Li Chenghong Feng Yaxin Chen Zhenyao Shen 《Environmental Earth Sciences》2013,69(5):1537-1547
The concentrations and speciation of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in the sediments of the nearshore area, river channel and coastal zones of the Yangtze estuary, China, were systematically investigated in this study. The concentrations of all heavy metals except Ni in the sediments of the nearshore area were higher than those of the river channel and coastal zones. In the nearshore area, the concentrations of most heavy metals except Hg in the sediments of the southern branch were higher than those of the northern branch because of the import of pollutants from the urban and industrial activities around. When compared with the threshold effect level (TEL) and geochemical background levels, Cr, Ni and As accumulated and posed potential adverse biological effects. The speciation analysis suggested that Cd, Pb and Zn in the sediments of the three zones showed higher bioavailability than the other heavy metals, and thus posed ecological risk. Significant correlations were observed among Cr, Cu, Ni and Zn (r > 0.77) in the nearshore area, Ni, Cu, Zn and Pb (r > 0.85) in the river channel and Ni, Cu, Cr, Pb and Zn (r > 0.75) in the coastal zone. Principal component analysis (PCA) indicated that the discharge of unban and industrial sewage, shipping pollution and the properties of the sediments (contents of Fe, Mn, Al, TOC, clay and silt) dominated the distribution of heavy metal in the nearshore area, river channel and coastal zones of the Yangtze estuary. 相似文献
17.
Zhongping Yang Wenxi Lu Yuqiao Long Xinhua Bao Qingchun Yang 《Journal of Geochemical Exploration》2011
Due to the rapid urbanization and industrialization that has occurred in China over the last few decades, metals have been continuously emitted into the urban environment and now pose a serious threat to human health. Indeed, there is a growing concern over the potential for pollution of urban soils with heavy metals. Therefore, an extensive soil survey was conducted in urban areas of Changchun, China, to evaluate the current status of heavy metal contamination in soils and to evaluate its potential sources. A total of 352 samples of urban soils were collected from urban areas of Changchun using a systematic sampling strategy in which one sample per km2 was taken (0 ~ 20 cm). The levels of Cu, Pb, Zn and the major elements (Mn, Al2O3, CaO, Fe2O3, MgO, SiO2, K2O and NaO) were then determined by X-Ray fluorescence spectrometry (XRF), while the level of Cd was determined by graphite furnace atomic absorption spectrometry (GF-AAS), and the Hg and As concentrations were determined by atomic fluorescence spectroscopy (AFS). The results indicated that, when compared with the background values of topsoil in the Changchun region, the topsoil in urban areas were enriched with metals, particularly Cu, Cd, Zn, Pb and Hg. The results of correlation coefficient analysis showed that Hg, As, Cd, Cu, Pb and Zn were significantly positive correlated with each other, while Cr and Mn formed another group. Moreover, significantly positive correlations were observed between pH and Zn, Pb, Cu, Cd, As and Hg, indicating that pH influences the distributions of these metals in urban soils in Changchun. Principal component analysis (PCA) was conducted to identify sources of heavy metals and the results revealed distinctly different associations among the trace metals and the major elements in the urban soils. The concentration of Cr appeared to be controlled by the parent material (natural sources), while Cu, Pb and Zn were mainly from vehicle emissions, with Zn primarily coming from vehicle tires. Additionally, Hg and As primarily originated from coal combustion, while Cd was mainly associated with industrial sources. According to the pollution index (PI) of each metal, the overall levels of metal pollution were not especially high, but there were clearly contaminated sites concentrated in the central and northeast portion of the studied region. The Nemerow integrated pollution index (NIPI) of the seven metals also indicated that urban soils in Changchun city were classified as having low level of pollution. 相似文献
18.
以锦州市为研究区,分析8种土壤重金属As、Cd、Hg、Cr、Cu、Pb、Zn、Ni的污染特征,采用单因子污染指数法、地累积指数法、内梅罗综合指数法和Hakanson潜在生态风险指数法确定锦州市土壤重金属污染程度,评价土壤重金属潜在生态风险.结果表明,锦州市土壤重金属Cd和Cr含量高于全国土壤及辽宁省土壤背景值,Cu、Hg、Ni和Pb含量高于辽宁省土壤背景值.采用单因子污染指数评价,Cd为中度污染,Hg、Pb、Cr、Ni和Cu为轻度污染.经地累积指数法评价,Cd为轻中度污染,其他重金属为无污染.内梅罗综合污染指数平均值为2.25,为中度污染等级.研究区综合潜在风险指数平均值为157.34,处于中等生态风险,造成局部地区土壤潜在生态风险较高的重金属为Cd和Hg. 相似文献
19.
系统采集了石家庄市区范围近地表降尘并分析了As、Cd、Cr、Cu、Hg、Ni、Pb、Zn重金属元素的含量,通过元素含量统计分析,发现它们存在较大的变异性,表明重金属含量的空间分布极不均匀。应用地统计模块中的Kriging空间插值分析方法和成图分析,可以看出市区内As、Cd、Cr、Cu呈大面积高值分布,Hg、Ni、Pb、Zn多呈点状污染分布。利用主成分因子分析和重金属元素源指示分析,认为石家庄市区近地表降尘重金属的主要贡献源以燃煤和交通为主。这为全面了解石家庄市区的空气质量状况并为该市大气环境污染治理、城市规划提供了重要依据。 相似文献
20.
Ten heavy metals, namely, Ag, As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn were partially extracted using aqua regia digestion method and analysed by ICP-AES from 56 stream sediment samples collected from River Orle, Igarra area, southwestern Nigeria. The analytical results were used to produce geochemical distribution maps for the elements and were subjected to univariate statistical analysis in order to evaluate the distribution and abundance of the heavy metals in the study area. The degree of pollution of these stream sediments by these heavy metals was evaluated by calculating such parameters as enrichment factors (EF), as well as pollution load and geo-accumulation indices (PLI and Igeo). Co, Cr, Cu, Ni, Pb and Zn are widely distributed in the drainage system while the distribution of Ag, Cd, As and Hg is restricted to only parts of the drainage system with Ag and Cd being localized to one sample site each near Epkeshi in the southern part of the study area. Cr and Pb display anomalously high concentrations, each from a site, also in the same locality where Ag and Cd were detected, indicating the likelihood that the four elements, Cr, Pb, Ag and Cd, are genetically related. Calculation of the enrichment factor (EF), pollution load index (PLI) and geo-accumulation index (Igeo) yielded results that indicate that all the 56 stream sediment sites, except one located about 4 km southeast of Epkeshi in the southern part of the Orle drainage system, are practically unpolluted by heavy metals. The relatively high metal concentration of this anomalous site having Pb EF of 62.5, PLI of 1.14 and Pb Igeo of 2.44 signifies Pb pollution. Both natural and anthropogenic sources of the Pb contamination around Epkeshi locality are possible. In conclusion, the levels of concentrations of heavy metals in the study area, in general, do not constitute any serious environmental risk except for Pb which needs to be monitored at only one site in the study area. Therefore the concentration ranges for the different heavy metals in the study area can serve as baseline environmental data against which the degree of pollution of these heavy metals can be evaluated in future. 相似文献