首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
Merri.  G 何武 《地质科学译丛》1995,12(2):40-44,87
本文报道了对两个古Pb-Zn矿中重金属元素迁移的监测,即金属元素通过大气尘降和河流运移向古矿周围的土壤、河流沉积物及其植被中迁移的情况。结果表明,古矿关闭后的80 ̄100年中相当大量的Cd、Pb、Zn和Cu(只在一个矿区)进行了土壤和水系中。在尾矿堆周围300m范围内,大气尘降的重金属元素每年有多达3.3kg的Cd、71Kg的Cu、373kg的Pb和104kg的Zn迁入了土壤和植被中。研究还发现,  相似文献   

2.
1998年3月、7月、10月,在对上海潮滩进行连续采样和观测的基础上,用原子吸收法测试了70个沉积物中的Cu,Pb,Zn,Cd.Cr的含量。结果表明:(1)上海潮滩重金属含量有如下顺序:Zn〉Cu〉Cr〉Pb〉〉Cd。(2)从高潮滩到中低潮滩,重金属的含量递减。(3)不同的采样位置对重金属的含量有显著影响。(4)由于季节的变化,重金属元素的含量变化的幅度也很大,就现有三个季度数据对东海农场进行统计  相似文献   

3.
我国一些重要夕卡岩Pb-Zn多金属矿床的交代分带   总被引:6,自引:3,他引:6  
赵一鸣 《矿床地质》1997,16(2):120-129
在我国一些重要夕卡岩Pb-Zn多金属矿床中,交代矿化分带十分明显,主要表现为围绕侵入体接触带或热源中心向碳酸盐围岩方向1,呈现有规律的带状分布1。根据有关岩浆岩和矿化组合的不同,可大致划分为三个匀代分带序列,总的分带序列是:Fe(MO)-Fe-Sn-Sn(W)-Cu-Cu-Zn-Zn,Pb(Ag)。  相似文献   

4.
青海东部碱性土壤中硒的形态特征   总被引:1,自引:0,他引:1  
以青海东部碱性富硒土壤为研究对象,通过对不同硒含量区表层土壤样的采集和分析,研究了天然富硒土壤中硒的形态特征。结果表明,研究区土壤中残渣态Se强有机态Se腐殖酸态Se水溶态Se碳酸盐态Se离子交换态Se铁锰氧化态Se;可利用态Se(即水溶态Se和离子交换态Se之和)占总Se比例为6.38%,潜在可利用态Se(即碳酸盐态Se和铁锰氧化态Se之和)占总Se比例为4.53%,这两项均高于国内部分酸性富硒土壤相应形态比例;不可利用态Se(即强有机态Se、腐殖酸结合态Se和残渣态Se之和)所占比例为89.09%,低于国内部分酸性富硒土壤中相应硒形态比例。青海碱性富硒土壤硒形态表现出高可利用态、高潜在可利用态和低不可利用态的特征。除铁锰氧化态Se外,其余6种形态均与全量Se呈显著正相关关系,而土壤总Se、腐殖酸态Se和残渣态Se与p H呈显著负相关。随着土壤碱性程度的增强,土壤总Se和不可利用态Se呈降低趋势。  相似文献   

5.
茶园土壤不同形态镍的含量及其影响因素   总被引:1,自引:2,他引:1  
通过自然茶园土壤采样和室内实验分析,探讨浙江、江苏和安徽13个茶园土壤镍的污染状况、形态分布规律以及不同形态镍的含量与土壤镍总量和土壤理化性质的关系。结果表明:部分茶园土壤受到不同程度的镍污染;茶园土壤镍的形态分布有一定差异,按镍的含量多少排序,一般为残渣态>交换态>铁锰氧化物结合态>有机结合态>碳酸盐结合态;除了交换态以外的所有其他形态的镍含量均随土壤镍含量的增加而显著增加;碳酸盐结合态、铁锰氧化物结合态和残渣态镍含量随土壤pH的升高呈显著增加趋势,而交换态镍则呈减少趋势,但不显著;随土壤有机质含量的增加,铁锰氧化物结合态镍显著减少,而其他形态增加或减少的趋势均不显著;碳酸盐结合态、有机结合态和残渣态的镍含量均随阳离子交换量的增加显著增加;随粘粒含量的增加所有形态中的镍呈增加趋势,但除了残渣态外增加趋势均不显著。  相似文献   

6.
西太平洋冲绳海槽烟囱硫化物矿床矿石化学特征与分带型式   总被引:12,自引:0,他引:12  
侯增谦  T. Urabe 《地球学报》1997,18(2):171-181
西太平洋冲绳海槽烟囱式硫化物矿床分布于琉球弧后扩张盆地、产于尹是名洼陷盆地(深1400m),其特征与日本黑矿类似。硫化物矿石及烟囱主要有3种化学类型:Pb-Zn-Ba型、Zn-Pb型和Cu-Zn型,三者分别代表温度不断升高的热液体系的早、中、晚3个成矿阶段产物,其中,Pb-Zn-Ba矿石及烟囱形成于高fo2环境和高流速、低温、富Pb、Zn、Ba热液体系,Cu-Zn矿石及烟囱形成于低流速、高温、富Cu热液体系,Zn-Pb矿石则介于其间。硫化物烟囱显示明显的矿物-化学分带。在Pb-Zn-Ba矿石(烟囱),Zn、Cd集中于烟囱中央,Ba、Fe、As、Sb、Ag、Pb集中于烟囱外带,Cu则富集于烟囱中外部。在Cu-Zn矿石,As、Sb、Fe、Ag、Au仍富集于烟囱外带,Cu、Zn、Pb则在烟囱中央富集。依此元素化学分带型式,建立了古代黑矿硫化物矿体分带与硫化物堆积模式。  相似文献   

7.
山西省临汾-运城盆地表层土壤中砷含量最大值45 mg/kg,最小值15.35 mg/kg,均值25.79mg/kg,大于全国背景值.不同相态含量差异较大,在所有63个样品中,水溶态、离子交换态、碳酸盐态含量较少(<1.5%),强有机结合态含量最少(<0.4%),铁锰氧化态、腐殖酸结合态含量较高(>10%),残渣态含量最高(约60%).铁锰氧化态、腐殖酸结合态、残渣态含量较高.  相似文献   

8.
铜精矿中铅锌的连续测定   总被引:2,自引:0,他引:2  
王建琴  王劲榕 《岩矿测试》2000,19(4):295-297
利用铜铁试剂分离Cu、Fe等干扰元素,同时铜铁试剂与Pb和Zn产生络合物吸附波,可连续测定铜精矿中的Pb和Zn。体系中铅峰在-0.54V,锌峰在-0.99V,线性范围Pb为80~1600μg/LZn为120~1200μg/L,检出限Pb为40μg/L,Zn为80μg/L,测定结果与参考值相符,RSD(n=3)Pb(n=3)Pb〈6%,Zn〈10%。  相似文献   

9.
河南水洞岭铜多金属矿床地球化学异常特征及找矿标志   总被引:3,自引:0,他引:3  
陈伟民 《矿产与地质》1998,12(6):427-431
水洞岭铜多金属矿床的岩石和土壤地球化学试验研究,表明岩石和土壤中Cu、Pb、Zn、As、Sb、Hg、Cd、Bi、Mo元素异常清晰,含矿岩系地球化学演化与元素组合变化的一致性,提出Cu、Pb、Zn、As、Sb、Hg、Cd、Bi、Mo元素可以作为指示元素,并建立了矿床的岩石、土壤地球化学异常概念模式。  相似文献   

10.
Gomati河近期沉淀物的重金属污染与人类活动的影响   总被引:5,自引:0,他引:5  
盖美 Singh  M 《世界地质》1998,17(1):51-55,59
在对Gomati河中近期沉淀的表层沉淀物的多种金属进行了浓度测定(Gr、Cu、Co、Fe、Mn、Ni、Pb、Zn和Cd),发现一些金属浓度(mg/kg)显著增加,其中Cd:0.26 ̄3.62、Cu:33 ̄147、Nr:45 ̄86、Pb:25 ̄77和Zn:90 ̄389。贯穿勒克瑙市区河流中,金属剖面图显示了沿顺流方向浓度增加,这是由于该区4个主要的排水网络排放废水所致。金属污染程度与地区背景值和全球  相似文献   

11.
Sequential core sediments from northwestern Taihu Lake in China were analyzed for grain size, organic carbon and heavy metal content. The sediments are composed of organic-poor clayey-fine silts. The chemical speciations of Cu, Fe, Mn, Ni, Pb, and Zn were also analyzed using the BCR sequential extraction procedure. Cu, Fe, Ni, and Zn are mainly associated with the residue fraction; Mn is concentrated mainly in exchangeable/carbonate fraction and residue fraction; and Pb mainly in Fe/Mn oxide fraction and organic/sulfide fraction. The exchangeable/carbonate fractions of Cu, Fe, Ni, Zn and Pb are lower. The fractions of Ni, Pb and Zn bound to the Fe/Mn oxide have significant correlations with reducible Mn; the organic/sulfide fractions of Cu, Mn, Ni, Pb, and Zn have significant correlations with TOC. The extractable fractions of Cu, Mn, Ni, Pb, and Zn are high at the top 4 cm of the core sediments as compared to those in the deeper layers, showing the anthropogenic input of heavy metals is due to rapid industrial development. The heavy metal pollution history of the sediments has been recorded since the late 1970s, determined by the result of ^137Cs dating.  相似文献   

12.
The BCR sequential extraction procedure is applied to probe into the speciation distribution of heavy metals (Cd, Cr, Zn, Cu and Pb) in lake sediments of Core XJ2 in Xijiu Lake, Taihu Lake catchment, China. The results showed that the effective species concentration of this five heavy metal elements increased obviously during the past century, the proportions of organic/sulphide fractions of Zn, Cu and Pb decreased while the Fe–Mn oxide fractions increased, and the proportion of Fe–Mn oxide fractions of Cd decreased while the exchangeable and carbonate fractions increased. The concentrations of exchangeable and carbonate fractions of these five elements were increased in the past century, especially the proportions of these fractions of Cd, Zn, Cu and Pb increased prominently. These changes could be attributed to the anthropogenic pollution. Since the changes of the heavy metal concentrations were corresponding to the history of human activities, especially the industry development, within the catchment.  相似文献   

13.
以深港西部通道填海区淤泥为研究对象,研究了重金属的化学形态特征,分析了填海工程活动带来的填海区地下水物理化学条件变化对重金属各个形态的影响。结果表明:除残留态外,填海区重金属存在形态主要为铁锰结合态、碳酸盐结合态和硫化物及有机结合态,其中,Pb和Ni以铁锰氧化物结合态和碳酸盐结合态为主,Cu以碳酸盐结合态和有机结合态为主,Zn以有机结合态和铁锰氧化物结合态为主,而Cd则以碳酸盐结合态为主。各金属在深港西部通道填海区淤泥的潜在迁移能力序列如下:Pb(39.68%)>Cu(31.59%)>Zn(20.49%)>Cd(12.80%)>Ni(10.98%)。  相似文献   

14.
Soils from historical Pb mining and smelting areas in Derbyshire, England have been analysed by a 5-step sequential extraction procedure, with multielement determination on extraction solutions at each step by ICP-AES. Each of the chemical fractions is operationally defined as: (i) exchangeable; (ii) bound to carbonates or specifically adsorbed; (iii) bound to Fe–Mn oxides; (iv) bound to organic matter and sulphides; (v) residual. The precision was estimated to be about 5%, and the overall recovery rates were between 85 and 110%. The carbonate/specifically adsorbed and Fe–Mn oxide phases are the largest fractions for Pb in soils contaminated by both mining and smelting. Most of the Zn is associated with Fe–Mn oxide and the residual fractions. Cadmium is concentrated in the first 3 extraction steps, particularly in the exchangeable phase. The most marked difference found between soils from the mining and smelting sites is the much higher concentrations and proportions of metals in the exchangeable fraction at the latter sites. This indicates greater mobility and potential bioavailability of Pb, Zn and Cd in soils at the smelting sites than in those in the mining area. The most important fraction for Fe and Al is the residual phase, followed by the Fe–Mn oxide forms. In contrast, the Fe–Mn oxide fraction is the dominant phase for Mn in these soils. In the mining area, most of the Ca is in the carbonate fraction (CaCO3), while the exchangeable and residual phases are the main fractions for Ca at the smelting sites. Phosphorus is mainly in the residual and organic fractions in both areas. The exchangeable fractions of Pb, Zn and Cd in soils were found to be significantly related to the concentrations of these metals in pasture herbage.  相似文献   

15.
The water ecosystem of the Vyshny Volochek Reservoir is characterized based on the study of the distribution of heavy metals speciations in the solid phase and pore waters of bottom sediments. Using the sequential extraction procedure, it is shown that Mn is mainly present in exchangeable and carbonate-bound forms; significant roles for Fe, Zn, Pb, and Co are played by forms that are bound to iron and manganese hydroxides and Cu and Ni are mainly bound to organic matter. Thermodynamic calculations have established the prevailing share of the following forms in pore waters: free ions for Zn, Ni, Co, and Cd, carbonate complexes for Pb, and fulvic complexes for Cu. It has been revealed that the speciation forms of heavy metals in bottom sediments depend on the lithological features and content of organic matter in sediments.  相似文献   

16.
黄河包头段不同粒级沉积物中重金属形态分布特征   总被引:3,自引:0,他引:3  
以黄河包头段为研究对象,探讨了该河段不同粒级沉积物中重金属的形态分布特征,并估算了各粒级沉积物对各形态重金属的贡献率。结果表明,铁锰氧化物结合态是黄河干流各粒级沉积物中Cu、Pb和Zn非稳定态的主导形态;总体上,黄河干支流沉积物中3种重金属各形态含量均随粒级增大而减小,表现明显的粒度效应;重金属形态分布的粒度效应是沉积...  相似文献   

17.
The objectives of the current study were to determine the chemical partitioning of Pb, Ni, Zn, Co, Cr, Mn, Fe and Cd using sequential extraction procedure and to assess the environmental risk associated with these metals in the farming soils along Zerqa River. Metal concentrations were measured by atomic absorption spectrophotometer. The study area demonstrated a wide range for pH, organic matter, carbonate contents, and cation exchange capacity, and is polluted with Pb, Cd, Mn, and Cu. The extensive use of fertilizers and pesticides in the agricultural activities, and discharge of treated and untreated wastewater are the major sources of pollution in the study area. Principal component analysis coupled with Pearson’s correlation analysis between the heavy metals revealed strong and positive correlation between these metals in the study area. According to the Risk Assessment Code (RAC), major portions of Cd and Mn are contained in exchangeable and carbonates fractions and therefore can easily enter the food chain. These metals pose a high to very high risk to the environment. Cu, Ni, Pb, and Zn pose medium risk, while Cr poses a low environment risk.  相似文献   

18.
Coastal reclamation has been carried out along the coastal areas near Shenzhen, China in a large scale since 1980s by dumping fill materials over the marine mud at the sea bottom. Usually the area to be reclaimed is drained first and some of the mud is air-dried for a few weeks before it is buried by fill. After reclamation, the terrestrial groundwater, which is relatively acidic and with high dissolved oxygen, gradually displaces the seawater, which is alkaline with high salinity. The changes in the burial conditions of mud and the properties of the pore water in the mud may induce the release of some heavy metals into the mud. Field survey confirms that the pH and salinity of the groundwater in the reclamation site are much lower than the seawater. Chemical analyses of mud and groundwater samples collected from the reclamation sites reclaimed in different years indicate that most of the heavy metals in the mud decrease gradually with time, but the heavy metals in the groundwater are increased. The release of heavy metals into pore water due to reactivation of heavy metals in the mud is of environmental concern. To understand why some of the heavy metals can be released from the mud more easily than others, a sequential extraction method was used to study the operationally determined chemical forms of five heavy metals (Cu, Ni, Pb, Zn, and Cd) in the mud samples. Heavy metals can be presented in five chemical forms: exchangeable, carbonate, Fe–Mn oxide, organic, and residual. Ni and Pb were mainly associated with the Fe–Mn oxide fraction and carbonate fraction; Zn was mainly associated with organic fraction and Fe–Mn oxide fraction, while Cu and Cd were associated with organic fraction and carbonate fraction, respectively. If the residual fraction can be considered as an inert phase of the metal that cannot be mobilized, it is the other four forms of heavy metal that cause the noticeable changes in the concentration of heavy metals in the mud. On the basis of the speciation of heavy metals, the mobility of metals have the following order: Pb (36.63%) > Cu (31.11%) > Zn (20.49%) > Ni (18.37%) > Cd (13.46%). The measured metal mobility fits reasonably well with the degree of concentration reduction of the metals with time of burial observed in the reclamation site.  相似文献   

19.
The heavy metal contents of Mn, Ni, Cu, Zn, Cr, Co, Pb, Cd, Fe, and V in the surface sediments from five selected sites of El Temsah Lake was determined by graphite furnace atomic absorption spectrophotometer. Geochemical forms of elements were investigated using four-step sequential chemical extraction procedure in order to identify and evaluate the mobility and the availability of trace metals on lake sediments, in comparison with the total element content. The operationally defined host fractions were: (1) exchangeable/bound to carbonate, (2) bound to Fe/Mn oxide, (3) bound to organic matter/sulfides, and (4) acid-soluble residue. The speciation data reveals that metals Zn, Cd, Pb, Ni, Mn, Cu, Cr, Fe, and V are sink primarily in organic and Fe–Mn oxyhydroxides phases. Co is mainly concentrated in the active phase. This is alarming because the element is enriched in Al Sayadin Lagoon which is still the main site of open fishing in Ismailia. Average concentration of the elements is mostly above the geochemical background and pristine values of the present study. There is a difference on the elemental composition of the sediment collected at the western lagoon (Al Sayadin Lagoon), junction, the shoreline shipyard workshops, and eastern beach of the lake. Depending upon the nature of elements and local pollution source, high concentration of Zn, Pb, and Cu are emitted by industrial wastewater flow (shoreline workshops), while sanitary and agricultural wastewater (El Bahtini and El Mahsama Drains) emit Co and Cd in Al Sayadin Lagoon. On the other hand, there is a marked decrease in potentially toxic heavy metal concentrations in the sediments at the most eastern side of the lake, probably due to the successive sediment dredging and improvements in water purification systems for navigation objective. These result show that El Temsah receives concentrations in anthropogenic metals that risk provoking more or less important disruptions, which are harmful and irreversible on the fauna and flora of this lake and on the whole ecobiological equilibrium.  相似文献   

20.
The Tessier sequential extraction scheme (SES) was applied to sediments from the Odiel river catchment (Iberian Pyritic Belt, SW of Spain), one of the most acid rivers on Earth, to assess the chemical association (exchangeable, carbonatic, bound to manganese and iron oxides, bound to organic matter and residual mineral) of heavy metals (Zn, Cd, Pb, Cu, Cr, Mn, Ni, Fe, and Hg). Sediments are very heterogeneous in their textural characteristics, showing different grain size. Twenty-seven samples were studied from from areas along the Odiel River, from the source to the mouth, with special interest in the Odiel Marshes Natural Park due to its ecological significance. Samples were classified as sandy (especially at the river mouth with low iron oxide and organic matter content) and clay-silty (in the middle of the river catchment with high iron oxide content). The numerous sandy samples with low pH values explain the low levels of metals upstream, although potential metals contributions arise from mining and ore. However, the presence of sulfate in the mining area and carbonate at the mouth may explain the high presence of lead and iron in these sandy zones. Some percentage of mobile Ni, Cu, and Zn were detected in the mining area, but the elevated relative percentage of exchangeable Cd in the estuary is even more remarkable. The percentage of Zn bound to carbonate is considerable in the catchment but especially in the estuary. However, Cu is only detected in the carbonate phase downstream, in spite of the low concentration of carbonate, which represents a drawback in the application of the Tessier SES to these types of samples. Finally, relatively high percentages of residual, non-mobile, Hg and Pb were observed, in the estuarine and mining areas, respectively. Sand, lime, and clay fractions of representative samples from Areas I, II, and III were used in a metal speciation study. Mainly, the elements analyzed had accumulated in the non-residual fractions. In the mining area of the Pyrite Belt, the elements analyzed are mainly bound to Fe–Mn oxides (Fe + Mn + Cu + Cr + Pb + Mn ± Zn) and the organic matter/sulfide fraction (Ni + Zn + Hg ± Cd), independent of sediment grain size. In conclusion, we show that the results of the study of chemical speciation in sediments from acid rivers are independent of the sediment grain size considered.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号