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1.
矿产品堆场土壤中重金属在环境中富集,随着元素的迁移、转化及地下水的循环,成为环境污染问题。本文将改进的顺序提取法(BCR)应用于矿产品堆场土壤中Cd、As、Pb的化学形态分析,结合这三种元素的性质,将堆场土壤中Cd、As、Pb分为可交换态、可还原态、可氧化态和残渣态,并利用电感耦合等离子体发射光谱法测定其含量。采用形态分析标准参考物质GBW 07436验证了三步提取态的准确性,并对6个矿产品堆场土壤中Cd、As、Pb形态含量进行分析,三步提取态加上残渣态质量分数之和与重金属总量进行了比较,回收率为85.54%~102.88%。通过对矿产品堆场土壤实际样品分析,Cd、As、Pb三种元素非残渣态含量顺序为Cd(79.40%~94.94%)Pb(24.27%~37.73%)As(22.89%~31.51%),表明Cd元素较为容易进入生物圈。该方法解决了港口堆场土壤中重金属化学形态提取问题,对污染土壤的治理具有指导意义。 相似文献
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随着中国经济发展,港口矿产品堆场重金属溶出作为港口土壤、水体的重要污染源不容忽视,重金属的溶出量与重金属种类有关。本文以天津港口矿石堆场中多类矿石为研究对象,通过静态浸泡实验,根据重金属的溶出情况确定典型矿产品和典型重金属因子,研究了时间、pH和温度对于典型矿产品中重金属溶出的影响。结果表明：铅精矿和铜精矿的重金属溶出量大,铅精矿中的Zn、Pb、Cd和铜精矿中的Ni是典型重金属因子,相应的溶出量比其他重金属高出1~3个数量级。随着时间的增加,铅精矿中Zn、Pb、Cd的溶出浓度增大,而铜精矿中Ni的溶出浓度基本上保持稳定。在pH 3.5~7.5的范围内,铅精矿中Zn、Pb、Cd和铜精矿中Ni的溶出浓度随pH值的变化均无显著性差异,且受pH的影响不大。在20~40℃的温度范围内,铅精矿中Zn、Pb、Cd的溶出浓度大体随温度升高而升高;铜精矿中Ni的溶出浓度则在30℃后呈现下降的趋势。本文初步探究了矿产品中重金属溶出的基本规律,为港口矿石堆场中矿产品重金属溶出的监控和防治提供了数据支持。 相似文献
3.
鄱阳湖水系重金属元素地球化学特征及入湖通量 总被引：1，自引：0，他引：1
江西省多目标区域地球化学调查显示,鄱阳湖流域河流两岸土壤(河漫滩沉积物)中存在明显的重金属异常带。为揭示河流两岸河漫滩沉积物(土壤)中重金属元素的来源、输送通量及其沉积历史,分别于丰水期和枯水期系统采集了鄱阳湖流域赣江、信江、饶河、抚河、修水及鄱阳湖湖水、悬浮物等样品,分析As、Cd、Pb等元素含量。研究表明：As、Pb、Cu、Zn等元素在研究区河流中的含量普遍较高,不同时期河水中的元素含量有较大的差异;各重金属元素在研究区河流迁移形式有很大的差别,As和Cd主要以离子态形式迁移,但Cd悬浮态迁移形式所占比例也很大;Pb、Zn、Cu和Ni主要以悬浮态形式迁移;重金属在河流水体和悬浮物两相中的分配受水体pH值、温度和悬浮物浓度等因素影响,不同的元素受这些因素的影响程度有很大的差别;按各支流输送通量,赣江和信江对湖区重金属元素输入通量的贡献最大,是鄱阳湖Cd等重金属元素的最主要来源。 相似文献
4.
山东烟台环境介质中重金属元素富集特征及与酸化土壤的关系 总被引：3，自引：0，他引：3
利用山东省烟台市生态地球化学调查及相关专题研究所取得的分析测试数据,通过高灵敏度的识别系统和多参数地球化学评价体系的建立,揭示了在重金属污染区内酸化的土壤环境中Cd、Hg、Pb、As等重金属元素活化迁移的地球化学机制、影响因素,以及浅层地下水和玉米等主要粮食作物籽实中重金属超标的原因及生态危害。与全国土壤基准值和背景值对比,研究区内Cd、Cr、Ni、Pb等元素的基准值相对偏高,Cd、Cr、Pb、Cu、Ni元素的背景值相对较高。As、Cd、Cr、Ni、Hg、Pb等存在于Ⅲ级及Ⅲ类以上土壤,是主要致污因子。典型金矿污染区内浅层地下水和玉米籽实中均检出超标重金属元素,影响浅层地下水环境质量的主要指标是Pb。达到Ⅲ类及以上水质标准的采样点数占研究区总采样点数的3.47%;玉米中的Cd含量相对较高。表层酸性、弱酸性土壤占土壤总面积的55.29%,土壤酸化趋势明显。随着土壤酸化程度的加深和范围扩大,导致土壤耕作层可给性营养元素的损失及某些毒性元素(Cd、Pb等)的释出和活化,提高了土壤中主要污染因子Cd、Hg、Ni、Pb、As等重金属的活化迁移能力;富含有机质的土壤中有利于对Cu、Zn、Pb、Cd的吸收,固重金属元素于土壤中,降低了土壤重金属污染的环境风险水平。研究结果为土壤修复、降低土壤重金属毒性提供了重要的科学依据。 相似文献
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6.
为查明雄安新区西南部耕层土壤的重金属元素污染状况,以唐河-唐河新道、清水河-府河流经区域的农田土壤为研究对象,采用野外采样和室内分析相结合的方法,调查研究耕层(0~20 cm)土壤As、Cu、Zn、Ni、Pb、Cr、Cd和Hg元素的质量分数和分布特征,分析评价重金属元素的污染状况及潜在生态危害风险等级。调查表明,除Cd外,其它重金属元素的平均值均低于土壤风险筛选值,有55%的Cd元素样本超出筛选值,其平均值超出筛选值约26.67%;土壤中As、Cu、Zn、Pb和Cd元素均有不同程度污染,污染程度排序为Cd＞Cu＞As(Zn)＞Pb,其中Cd的污染风险区大面积分布在研究区的中东部,具有典型面状污染特征,Cd元素重度和中度污染的比例分别为3.09%和12.74%;8种重金属元素潜在的生态危害程度排序为Cd＞Hg＞As＞Pb＞Cu＞Ni＞Cr＞Zn,其中Cd的生态危害为强、很强和极强的超标率分别为32.43%、31.27%和4.63%;RI值为强生态危害及其以上的比例占38.61%,平均值为287.39。综上表明,雄安新区西南部耕层土壤整体存在重金属元素的污染,重金属的潜在危害程度为中等风险。 相似文献
7.
为探究西昌普诗碎屑岩地区紫色土中8种重（类）金属元素（Cu、Cd、Ni、Pb、Zn、Hg、As、Cr）的迁移富集特征及潜在生态风险,选取白垩系小坝组4个典型岩石-土壤剖面进行了系统的采样、测试和分析。结果表明,研究区土壤呈酸性—弱酸性,重金属元素Cd、Pb、Zn在剖面表层富集,与外源重金属元素叠加有关。此外,重金属元素的迁移富集特征还受到剖面风化程度、淋溶淀积作用、黏土矿物吸附作用及大气降尘等多种因素共同影响。单因子指数评价和内梅罗综合指数评价表明,研究区4个剖面均不存在土壤重金属元素污染问题。潜在生态风险评价表明研究区土壤整体处于低潜在生态污染水平,Hg和Cd元素存在中度潜在生态风险等级。建议相关部门加强土壤重金属元素的检测和监控力度,科学降低土壤重金属潜在生态风险。 相似文献
8.
通过对山东省小清河流域土壤重金属污染现状的调查研究,查明土壤重金属污染状况,元素来源和分布迁移规律,从而为该区土壤重金属污染的科学治理提供有效依据。研究发现,小清河沿岸地区的重金属污染主要表现为As、Cd、Cr、Ni等元素的污染;依据内梅罗污染指数评价方法发现研究区存在重金属污染的土壤总面积为880.5 km2,未受到重金属污染的土壤面积为1 822.1 km2,分别占全区总土壤面积的32.58%和67.42%,其中上游的济南市城区北园镇至华山镇区域的小清河两岸是重污染区。对小清河流域土壤重金属来源的探析表明,大气干湿沉降是土壤重金属污染的主要来源;土壤重金属的生物有效性评价显示重金属元素Cd的活动态比例高达56.17%,活化迁移能力强,是该区对生态环境危害性最大的污染因子。此外,As、Cd、Cr、Pb等重金属元素的活动态含量明显受pH值和Corg含量的制约,在低pH值、高Corg含量的土壤区应高度重视As和Cd的污染问题。 相似文献
9.
通过对辽宁铁岭柴河铅锌矿及周边地区的土壤测量及柴河水库河漫滩沉积剖面的同位素测年研究,发现柴河铅锌矿开采导致的土壤重金属污染主要集中在柴河铅锌矿区周边3~5 km的范围内,土壤pH值表明土壤明显酸化。污染历史重建显示,1820年以来,随着沉积物中S含量的不断升高,其pH值累计下降2个单位;1900年以来河漫滩沉积物中的Cd、Pb、Zn累积明显;铅锌矿停止开采后,沉积剖面中Pb、Hg含量逐年降低;汇水域内的土壤酸化仍可导致土壤中累积的Cd和Zn对水库水体和库底沉积物造成二次污染,对水库鱼类的安全具有潜在风险。 相似文献
10.
云蒙湖表层沉积物重金属分布特征及风险评价 总被引：1，自引：0，他引：1
为了解云蒙湖表层沉积物中重金属的污染状况,选取云蒙湖沉积物中6种重金属(Cu、Zn、Pb、Cr、Cd、As)作为研究对象,测定并分析其在云蒙湖表层沉积物中的分布、来源及生态风险,以期为云蒙湖沉积物中重金属污染治理及饮用水安全保障提供依据。采用富集系数法、相关性分析及聚类分析对重金属来源进行分析,并选用富集系数法、地累积指数法和潜在生态危害指数法对重金属污染程度及潜在生态危害进行了评价。结果表明:云蒙湖表层沉积物中6种重金属Cu、Zn、Pb、Cr、Cd、As平均含量分别为20.9、73.1、23.1、62.0、0.4和4.5 mg/kg;与临沂市土壤背景比较,Cd、Zn和Cr的含量超过临沂市土壤背景值,Cd污染最严重。重金属来源分析结果显示:Cd受人类活动影响较大,可能与区域农业和林业施肥有关;Cu、Zn、Pb、Cr和 As这几种重金属以自然来源为主。综合富集系数法、地累积指数法和潜在生态危害指数法3种评价方法的结果得出,云蒙湖表层沉积物中Cd 为最主要的污染元素,且具有较强的生态危害。 相似文献
11.
Hydrochemical monitoring and heavy metal speciation by sequential extraction techniques indicate direct relationships among enrichment of the heavy metals (copper, lead, zinc, iron, manganese, and cadmium), soil acidification, and salinization in Kedron Brook floodplain area of Brisbane, Australia. Assessment of modes of occurrence and distribution pattern of the heavy metals in soil, sediment, and water environments of this coastal plain indicates that the total concentrations and reactive fractions of these metals are elevated in soil and channel bed sediments. Such geochemical signatures reflect the complex influence of sources and a combination of natural and anthropogenic processes on concentration and dispersion within the coastal zone. According to a working model presented, the enrichment of the heavy metals, like cadmium, in the soil and sediment profiles is triggered by capillary pumping during low groundwater standing levels, when the metals are in a stable form associated with dry gels. During higher groundwater levels and occasional flood events, these metals become mobilized when the gel material is transformed into soluble colloidal phase.This study indicates that the potential impacts of heavy metal pollution on the coastal ecosystems can not be assessed and managed in isolation solely by considering the natural cause-effect relationships. The complex nature of sediment-soil-water interactions in the coastal hydrodynamic zones can produce a manifold of effects, including mobilization, concentration, and/or dispersion of heavy metals at both short and longer time scales. In the case of Kedron Brook, chemical erosion due to variation in natural climatic and hydrodynamic conditions contributes significantly to concentration of heavy metals in the coastal environments. Therefore, a sound understanding of the prevailing hydrogeochemical processes is essential for prediction of the fate of heavy metals and establishment of meaningful coastal zone management strategies. 相似文献
12.
广西某铅锌矿区废水汇集洼地土壤重金属污染调查与评价 总被引：8，自引：3，他引：5
对某铅锌矿废水汇集的岩溶洼地土壤重金属镉、铜、铅、锌、铬、砷和汞的含量进行调查分析,运用单项污染指数与综合污染指数相结合的方法对土壤环境质量状况和采用Hakanson潜在生态指数法对土壤重金属污染潜在生态风险进行评价。结果表明,该区块土壤受到重金属镉、锌、汞、铅的严重污染,其污染指数均大于1,尤其是镉污染指数高达88.4,其后依次为锌和汞,铅最小;剖面上,A、B、C层,即0~30 cm、30~60 cm和60~90 cm土壤,均已受到不同程度的重金属污染,而且污染程度A层>B层>C层,其综合污染指数分别为67.0、11.9和8.8,各自的潜在生态风险指数分别为2 921.0、543.4、421.2,对应的潜在生态风险程度分别为极强、强、强。由此可见,该岩溶洼地土壤不仅镉、锌、汞、铅污染严重,而且其生态风险也很大,但土壤中基本没有受铜、铬、砷污染。在该洼地土壤重金属污染物没有清除前,建议禁止种植食用农产品,而改为种植非食用型经济作物。 相似文献
13.
K. M. Mohiuddin Ph.D. Y. Ogawa Ph.D. H. M. Zakir Ph.D. K. Otomo Ph.D. N. Shikazono Ph.D. 《International Journal of Environmental Science and Technology》2011,8(4):723-736
Water and sediment samples were collected from 20 location of the Buriganga river of Bangladesh during Summer and Winter 2009 to determine the spatial distribution, seasonal and temporal variation of different heavy metal contents. Sequential extraction procedure was employed in sediment samples for the geochemical partitioning of the metals. Total trace metal content in water and sediment samples were analyzed and compared with different standard and reference values. Concentration of total chromium, lead, cadmium, zinc, copper, nickel, cobalt and arsenic in water samples were greatly exceeded the toxicity reference values in both season. Concentration of chromium, lead, copper and nickel in sediment samples were mostly higher than that of severe effect level values, at which the sediment is considered heavily polluted. On average 72 % chromium, 92 % lead, 88 % zinc, 73 % copper, 63 % nickel and 68 % of total cobalt were associated with the first three labile sequential extraction phases, which portion is readily bioavailable and might be associated with frequent negative biological effects. Enrichment factor values demonstrated that the lead, cadmium, zinc, chromium and copper in most of the sediment samples were enriched sever to very severely. The pollution load index value for the total area was as high as 21.1 in Summer and 24.6 in Winter season; while values above one indicates progressive deterioration of the sites and estuarine quality. The extent of heavy metals pollution in the Buriganga river system implies that the condition is much frightening and may severely affect the aquatic ecology of the river. 相似文献
14.
The importance of polluted alluvial soils as a potential diffuse source of heavy metals was investigated in a catchment of
the Matylda stream affected by an abandoned lead and zinc ore mine in Upper Silesia, southern Poland. This was attempted by
means of standard groundwater analyses performed together with measurements of Cd, Pb, Zn, Fe and Mn concentrations in soil
and groundwater. The Matylda stream, receiving mine water, was converted in the 20th century into a straight channel directed
in its middle reach over the valley bottom. This changed the drainage direction of the Matylda stream water. During mining
operations, groundwater seepage, combined with surface drainage by shallow ditches caused pollution of sandy soils exceeding
over 100 mg/kg of Cd, 24% of Zn and 4% of Pb at surface or subsurface soil horizons, and reaching at least 60 cm in depth.
After mine closure in the 1970s, the network of ditches appears to be a source of Ca, Mg, chlorides, carbonates and nitrates,
as indicated by the more or less regular increase of these major ion concentrations in groundwater down ditches. Whereas,
the ditches are a sink rather than a source of zinc, cadmium and lead in permanently dry reaches, or transition zones in reaches
with surface water flowing periodically. The metal concentrations and distribution in soil and groundwater suggest the slow
mobilization of heavy metals stored in the valley bottom and the minor importance of soil as a diffuse source for surface
water pollution. 相似文献
15.
Assessment of heavy metal pollution in the urban stream sediments and its tributaries 总被引：11，自引：8，他引：3
K. Sekabira H. Oryem Origa Ph.D. T. A. Basamba Ph.D. G. Mutumba Ph.D. E. Kakudidi Ph.D. 《International Journal of Environmental Science and Technology》2010,7(3):435-446
Globally, aquatic ecosystems are highly polluted with heavy metals arising from anthropogenic and terrigenous sources. The objective of this study was to investigate the pollution of stream sediments and possible sources of pollutants in Nakivubo Channel Kampala, Uganda. Stream sediments were collected and analysed for heavy metal concentration using flame atomic absorption spectrophotometer. The degree of pollution in Nakivubo channelized stream sediments for lead, cadmium, copper, zinc, manganese and iron was assessed using enrichment factor, geo-accumulation index and pollution load index. The results indicated that (1) the sediments have been polluted with lead, cadmium and zinc and have high anthropogenic influences; (2) the calculation of geo-accumulation index suggest that Nakivubo stream sediments have background concentration for copper, manganese and Fe (I geo ≤ 0); (3) factor analysis results reveal three sources of pollutants as explained by three factors (75.0 %); (i) mixed origin or retention phenomena of industrial and vehicular emissions; (ii) terrigenous and (iii) dual origin of zinc (vehicular and industrial). In conclusion, the co-precipitation (inclusion, occlusion and adsorption) of lead, cadmium and zinc with manganese and iron hydroxides, scavenging ability of other metals, very low dissolved oxygen and slightly acidic to slightly alkaline pH in stream water could account for the active accumulation of heavy metals in Nakivubo stream sediments. These phenomena may pose a risk of secondary water pollution under sediment disturbance and/or changes in the geo-chemistry of sediments. 相似文献
16.
土壤重金属污染是中国当前最突出的环境污染问题。污染调查公报显示全国土壤重金属总超标率为16.1%,其中镉的点位超标率为7%,对粮食安全产生威胁。本文介绍了中国土壤重金属污染的现状,梳理了土壤重金属污染检测分析的传统和新兴方法技术,包括重金属全量、化学形态和生物可利用态含量等。同时阐述了土壤重金属污染检测分析技术发展趋势,如分子水平上的重金属元素检测和生物传感技术应用于重金属元素检测。考虑到土壤系统的复杂性,未来发展的重点应实现地学、化学和生物学的交叉,加强重金属生物有效性的理论研究,形成土壤重金属污染的生物有效度分析检测指标体系,使评价方法科学化、标准化、统一化。进一步推动我国的有关分析测试技术标准与国际标准接轨。 相似文献
17.
A. R. Karbassi Ph.D. F. Torabi M.Sc. F. Ghazban Ph.D. M. Ardestani Ph.D. 《International Journal of Environmental Science and Technology》2011,8(4):841-852
In the present study sediment and water samples collected from Kowsar Dam reservoir in Kohkiluye and Boyerahmad Province, southwest of Iran, are subjected to bulk digestion and chemical partitioning. The concentrations of nickel, lead, zinc, copper, cobalt, cadmium, manganese and iron in water and bed sediment were determined by atomic absorption spectrometry. The concentrations of metals bounded to five sedimentary phases were estimated. On this basis, the proportions of natural and anthropogenic elements were calculated.The anthropogenic portion of elements are as follows: zinc (96 %)> cobalt (88 %)> iron (78 %)> magnesium (78 %)> nickel (78 %)> copper (66 %)> lead (63 %)> cadmium (59 %). The results show sediment contamination by nickel, cadmium and lead, according to the world aquatic sediments and mean earth crust values. Manganese and copper have strong association with organic matter and are of high portion of sulfide bounded ions. Finally, The degree of sediment contamination was evaluated using enrichment factor, geo-accumulation index (Igeo) and pollution index (IPoll). The sediments were identified to be of high cadmium and lead pollution index. The pattern of pollution intensity according to enrichment factor is as follows; manganese (1.25) < copper (1.63) < zinc (1.93) < cobalt (2.35) < nickel (3.83) < lead (12.63) < cadmium (78.32). Cluster analysis was performed in order to assess heavy metal interactions between water and sediment. Accordingly, nickel, cadmium and copper are earth originated. Zinc, copper and manganese are dominated by pH. All the elemental concentrations in water and sediment are correlated except for sedimental copper. 相似文献
18.
富硒土地是生产富硒农产品的宝贵资源,黑色岩系形成的土壤通常富含硒和重金属元素。为了指导这类富硒土地资源的安全开发利用,选择浙江中部典型黑色岩系分布区,通过调查土壤-作物中硒和重金属的浓度及生物有效性,评价农产品富硒率,识别作物重金属超标风险。结果显示:研究区富硒土壤占38%,足硒土壤占62%,水稻和莲子富硒率分别为85.71%和100%;受黑色岩系风化成土影响,研究区土壤镉含量介于污染筛选值和风险管控值之间的样品比例为26%,且Cd活动态和潜在活动态所占比例分别为57%和40%,水稻籽实中Cd超标率为31%,莲子Cd含量均不超标。基于土壤重金属总量和形态的风险评价表明,富硒土壤开发利用的风险区主要位于西皮山岗和腰塘边一带,建议禁止种植农产品,其他黑色岩系发育的富硒丘陵地区,虽然土壤镉含量较高,但因土壤Cd的生物有效性和水稻中Cd的超标率较低,应加以保护和合理开发利用。 相似文献
19.
In recent years, there has been a rapid growth in the two industrial port cities of Iran, the port of Mahshahr and the port of Imam Khomeini. In spite of their importance for the economy, the two cities require monitoring and assessment from an environmental and human health perspective. In this study, environmental quality and heavy metals pollution of soils influenced by human activities were investigated. A total of 30 soil samples were collected and subjected to detail physicochemical characterization. The results showed high levels of heavy metals in the urban soils of port of Mahshahr (POM) and elevated respective levels in surface soils of the port of Imam Khomeini (PIK) with Ni being significantly higher than those in POM. The integrated pollution index (IPI) values of metals ranged from 1.22 to 1.87 in POM and 1.52 to 3.31in PIK, 50% of soil samples in PIK were classified as highly polluted, and all of the soil samples in PM were classified as moderately polluted. These results are in accordance with Enrichment Factor (EF) values, which showed the role of anthropogenic activities in the soil heavy metal enrichment. Moreover, the highest potential ecological risk index (RI) was found in the sites of petrochemical industries in PIK indicating serious metal contamination. Statistical analysis showed that heavy metals were mainly controlled by human activities. The results showed more dense industrial activity in PIK is responsible for higher pollution. This study establishes a benchmark against which future monitoring and remediation programs can be based on. Because of proximity to the Persian Gulf, continued the release of contaminants into the region, could have adverse biological health effects. 相似文献
20.
P. S. Harikumar Ph.D. U. P. Nasir M.Sc. M.Phil. in Chemistry M. P. Mujeebu Rahman M.Sc. in Chemistry 《International Journal of Environmental Science and Technology》2009,6(2):225-232
Five sediment cores from the fresh water region of the Vembanad wetland system were studied for the trace element contents The average concentration of iron, manganese, nickel, copper, zinc, cadmium, lead, mercury and chromium were determined. The core samples were collected using gravity type corer, digested with a mixture of nitric acid and perchloric acid and analyzed by atomic absorption spectrophotometry. Heavy metals such as iron, copper, nickel and zinc reported enrichment towards the surface of the core sediment sample collected from the centre of the lake. Lead, cadmium and mercury showed uniform distribution through out the core. Quality of the sediments were evaluated based on sediment quality guidelines, pollution load index, sum of toxic units and with effect range low/effect range median and threshold effect level/probable effect level values of Environmental Protection Agency guidelines. The degree of contamination for each station was determined. The concentration of different heavy metals has been compared with the world average concentration of shale values. Results of the analysis showed that Vembanad lake is facing serious metal pollution with increased rate of deposition. 相似文献