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 31 毫秒
1.
Dissolved electroactive concentrations of zinc, cadmium, lead and copper in river Rhine and North Sea samples have been measured at natural and lower pH values by differential pulsed anodic stripping voltammetry using a Kemula-type hanging mercury drop electrode. Average concentrations detected in North Sea samples at salinities ? 32‰ S and their range are (in μgl?1): 3.9 (2.0–7.5) for zinc, 0.23 (0.13–0.31) for cadmium, 0.3 (0.1–0.6) for lead and 0.3 (0.25–0.60) for copper (pH 8.1). The APDC-MIBK extracting/concentrating method, followed by AAS measurement applied to the same samples, resulted in 3.9 (2.0–7.5) for zinc, 0.11 (0.01–0.27) for cadmium, 0.5 (0.2–0.9) for lead and 1.6 (0.7–3.2) for copper. A fraction of the electroactive concentrations at pH 2.7 (6.1 for Zn) is electroactive at pH 8.1. The fractions are 100% for Cd, 20% for Cu, 13% for Pb and 40% for Zn. The remaining fractions are partly composed of organically bound species in solution. The low value for lead may be caused by the presence of particulate lead that is dissolved at low pH.Ionic copper and lead species, added separately to seawater at pH 8.1 are removed from the electroactive form, and taken up in (organic) complexes in the same ratio (at least for copper) as the species already present. Added ionic zinc is not removed within the time scale of the measurements (30 min). North Sea water at the natural pH has a complexing capacity, probably due to the presence of dissolved organic compounds, in a concentration equivalent to 3.10?7M copper. The complexing capacity is zero at pH 2.7. The usual method of standard addition for the determination of electroactive copper and lead concentrations may lead to erroneous results in samples where complexation of this type occurs.  相似文献   

2.
Since an important fraction of the organic matter produced by salt marshes is decomposed in situ, macro-benthic communities are particularly exposed to the trace metals retained by these systems. Yet, few studies have investigated the macro-benthic communities using the between-root sediment habitat of the salt marsh halophytes (salt-tolerant plants), or the effect of trace metal pollution on its population dynamics. In the present study, samples were collected in vegetated and unvegetated sediment, in three salt marshes in the Tagus estuary, for trace metal concentration determination in the sediment and in the halophytes roots, grain size determination and macro-benthic organism identification. Data analysis revealed that the distribution of macro-benthic organisms is mainly determined by metal contamination, metal type and by the presence/absence of halophytes, not by the halophyte species. Five different associations were identified: resistant organisms were associated with the highest concentrations of lead (sediment); tolerant organisms with zinc, copper (sediment and roots) and lead (roots); cadmium in the sediment with a lack of macro-benthic life; sensitive organisms with low levels of metals except for cadmium in the roots; and macro-benthos typical of intertidal mudflats with unvegetated areas with low metal contamination.  相似文献   

3.
渤海中部表层沉积物中重金属赋存相态及来源   总被引:1,自引:1,他引:0  
近年来由于环渤海经济圈的快速发展,渤海接受了来自周边河流、沿岸排污及海上油气开采所产生的大量的重金属等污染物质,使得渤海的生态环境系统面临前所未有的压力。本文采用电感耦合等离子质谱仪(ICP-MS)对采自渤海中部的25个表层沉积物样品中的Cu、Co、Ni、Zn、Pb、Cr、Cd等重金属元素的含量和赋存相态进行了分析,探讨了重金属分布规律、污染状况及来源。研究结果表明,Cu、Co、Ni、Zn、Cr在渤海湾的近岸区域和渤海中部泥质区有较高的含量,而Pb和Cd则在整个研究区的含量都较高;表层沉积物中Cu、Co、Ni、Zn、Cr主要以残渣态形式存在,而Pb和Cd则具有较高的非残渣态含量;生态风险评价结果表明该区表层沉积物未受到Co、Ni、Cr的污染,Cu、Zn、Pb和Cd则为未污染-中等程度污染。重金属元素Co、Ni、Cr以自然来源为主,在沉积物中的分布主要受沉积物物质组成的影响,而Cu、Zn、Pb,尤其是Cd,则受到了人类活动的显著影响。黄河沉积物是研究区表层沉积物中重金属的主要来源,影响范围涵盖了本区大部分区域,但在研究区的北端受到滦河来源物质的影响,渤海湾和研究区中部则受到海河物质和大气沉降来源重金属的一定影响。  相似文献   

4.
The concentrations of cadmium, copper, lead and zinc were measured at two locations in surface waters of the western North Atlantic. Samples were collected upstream of the research vessel in 1-1 teflon bottles, and in a 30-1 teflon-coated Go-flo bottle. Surface mixed-layer samples were also collected at each location by ship cast using this same Go-flo sampler. A comparison of the three sampling modes shows that all the samples taken with the Go-flo sampler possessed much higher concentrations of zinc (7–10-fold) and lead (2–3-fold) than those collected directly in teflon bottles. No apparent differences were noted at each station in the concentrations of either copper or cadmium among the samples collected by the three different procedures. The measured values for copper and cadmium in these waters are in good agreement with recent reports for the western North Atlantic.  相似文献   

5.
东海泥质区表层沉积物中铜和铅的赋存形态研究   总被引:1,自引:0,他引:1  
2007年11月在东海泥质区13个站点采集了表层沉积物样品,用连续提取法分离并测定了铜和铅的赋存形态。结果表明,铜主要赋存于易还原态(铁锰氧化物结合态),含量为1.2~5.1μg/g,平均值为3.3μg/g;铅主要赋存于碳酸盐结合态,含量为1.9~7.3μg/g,平均值为5.3μg/g。泥质区铜和铅的有机结合态和易还原铁锰氧化物结合态与水深之间的呈明显的相关关系,碳酸盐结合态则与水深不相关。铜和铅非残渣态总量与采样站点水深之间的关系受控于其主要赋存形态,反映了重金属形态分布受到陆源输入和在水体中迁移等因素的影响。济州岛西南泥质区表层沉积物中铁锰氧化物结合态的铜和铅含量高于其他海区表层沉积物,可能是由于沉积物再悬浮所致。  相似文献   

6.
Toxicities of sediments from San Diego and San Francisco Bays were compared in laboratory experiments using sea urchin (Strongylocentrotus purpuratus) embryos exposed to pore water and at the sediment-water interface (SWI). Toxicity was consistently greater to embryos exposed at the SWI to intact (unhomogenized) sediment samples relative to homogenized samples. Measurement of selected trace metals indicated considerably greater fluxes of copper, zinc, and cadmium into overlying waters of intact sediment samples. Inhibition of sea urchin embryo development was generally greater in sediment pore waters relative to SWI exposures. Pore water toxicity may have been due to elevated unionized ammonia concentrations in some samples. The results indicate that invertebrate embryos are amenable to SWI exposures, a more ecologically relevant exposure system, and that sediment homogenization may create artifacts in laboratory toxicity experiments.  相似文献   

7.
汕头湾表层沉积物重金属元素含量和分布特征研究   总被引:16,自引:0,他引:16  
乔永民  黄长江 《海洋学报》2009,31(1):106-116
于2002年9月在汕头湾采集了13个表层沉积物样品,测定了它们的细粒级组分、总有机质、铝、铁、锰、铜、锌、铅、镉、铬、镍、钴的含量,对其分布特征及其彼此之间相关性进行了分析,并以南海陆架区重金属含量为背景值计算了汕头湾表层沉积物重金属元素的富集系数,结果表明,铁、锰、铜、锌、铅、镉、铬、镍、钴的含量范围分别为2.91%~3.94%,427.85~810.96,24.43~79.49,84.83~248.50,35.56~50.25,0.30~1.75,36.11~74.22,16.99~31.69,8.22~10.87 mg/kg,其分布由汕头湾上游的榕江口至湾口呈波浪状递减(锰除外)。汕头湾表层沉积物中各重金属的富集系数均大于1,其中富集系数从大到小的重金属元素是铜、镉、铅、锌、镍、铬和锰。人为排污、水动力作用、黏土含量、盐度是多数重金属元素分布特征的控制因素。锰的分布特征更多地取决于汕头湾水域的氧化还原条件。  相似文献   

8.
Announcement     
Cadmium, lead and copper have been determined in both dissolved and particulate phases for 130 surface-water samples from the coastal zone of Scotland and England in the western North Sea. The concentrations reported are, in general, lower than those published previously for the same area.The distribution of total metal concentration between the dissolved and particulate phases varies for the three elements. The lead distribution is dominated by its associations with particulate material while cadmium shows the reverse behaviour, existing almost totally in the dissolved phase. Copper is intermediate in behaviour, with the dissolved phase generally being dominant.An inverse relationship between salinity and dissolved copper concentration suggests a freshwater origin for this element. It is suggested that sedimentary and/or anthropogenic sources affect dissolved copper concentrations in coastal waters. The dissolved lead distribution reveals plumes of contaminated coastal water. The lead distribution is, however, dominated by associations with particulate material and sediments which produce a sharp concentration gradient close to the coast. The Humber estuary is identified as a significant source of cadmium to the North Sea.  相似文献   

9.
Cadmium, lead and copper have been determined in both dissolved and particulate phases for 130 surface-water samples from the coastal zone of Scotland and England in the western North Sea. The concentrations reported are, in general, lower than those published previously for the same area.The distribution of total metal concentration between the dissolved and particulate phases varies for the three elements. The lead distribution is dominated by its associations with particulate material while cadmium shows the reverse behaviour, existing almost totally in the dissolved phase. Copper is intermediate in behaviour, with the dissolved phase generally being dominant.An inverse relationship between salinity and dissolved copper concentration suggests a freshwater origin for this element. It is suggested that sedimentary and/or anthropogenic sources affect dissolved copper concentrations in coastal waters. The dissolved lead distribution reveals plumes of contaminated coastal water. The lead distribution is, however, dominated by associations with particulate material and sediments which produce a sharp concentration gradient close to the coast. The Humber estuary is identified as a significant source of cadmium to the North Sea.  相似文献   

10.
The present study was undertaken for assessing the level of heavy metals such as iron, manganese, zinc, copper, nickel, cadmium, lead, and cobalt in recent sediment samples of Safaga Bay, Egypt. Concentration of heavy metals in sediments shows significant variability and ranges from 863.37 to 1144.93 ppm for Fe, 64.29–586.8 ppm for Mn, 2.7–12.68 ppm for Zn, 3.01–7.2 ppm for Pb, 1.53–3.29 ppm for Ni, 0.55–1.57 ppm for Co, 0.16–1.37 ppm for Cu, and 0.22–0.4 ppm for Cd.

Sediment pollution assessments were carried out using an enrichment factor and geoaccumulation index. The calculation of enrichment factor showed that Cd is enriched by 4.1 due to phosphate sources in Safaga Bay. The Geoaccumulation index results revealed that there are positive and negative correlations between Fe, Zn, Mn, Pb, Ni, Cu, Co, and Cd indicating that these metals have complicated geochemical behaviors.  相似文献   

11.
Accumulation of cadmium, copper, lead and zinc in the tissues of Mytilus edulis planulatus was examined under cyclic conditions of exposure in order to establish whether the rate of accumulation of the metal is proportional to the time exposed to the elevated concentrations. When exposed to a single metal, the accumulation of lead and zinc was directly proportional to the exposure time, but that of copper was not. Under simultaneous exposure to all four metals both lead and cadmium were accumulated in direct proportion to the exposure time, while copper and zinc were not. Accumulation of the three metals cadmium, copper and zinc was influenced by the presence of other metals.  相似文献   

12.
Concentrations of cadmium, lead and copper have been determined in the lower estuary of the St. Lawrence River during the summer of 1972 (from May to August). Seven sample stations distributed in the estuary have been studied. Analysis measurements have been made using atomic absorption spectrophotometry and are related to the soluble metals. The concentrations of cadmium are low and no important variations occur. Mean analysis of cadmium abundance gives a value of 1.05 μg/l. Similar variations are observed for copper and lead contents with a Cu/Pb ratio which is nearly equal to unity. Average concentrations for all the stations are 3.11 μg/l for copper and 3.48 μg/l for lead. Higher values are measured for copper and lead during the month of May and these are related to the fresh-water inflow arising from the thawing period. The lowest concentrations are observed during the months of June and July and are in correspondence with the spring period of intense primary production. The biologic-dynamic conditions affecting the concentrations of cadmium seem to be different from those affecting copper or lead contents (without considering pollution phenomena). The highest average values for copper and lead have been found on the south shore of the estuary. The values obtained in this work compared favourably with other results gathered in the neighbouring area.  相似文献   

13.
渤海莱州湾表层沉积物中金属元素分布及环境质量   总被引:3,自引:1,他引:2  
利用X-射线荧光光谱仪、等离子质谱仪或原子荧光光度计测定了莱州湾表层沉积物中金属元素的含量,探讨了它们的分布特征、来源及污染程度,结果表明,沉积物中铜、锌、铅、镉、砷、镍、铬、钴、钒、钪、铁、锰的含量由近岸向湾内递减,莱州湾北部海域的含量大于南部的。银含量高的沉积物主要分布在莱州湾中部偏西南的环流中心区。沉积物中砷和镍含量超过ERL值,潜在生态风险较高。富集系数和主成分分析显示,沉积物中铁、铜、锌、镉、砷、铬、镍、钴、锰、钒和钪为无富集,砷为轻度富集,铅和银为中度富集。铁、铜、锌、镉、铬、镍、钴、锰、钒、砷和钪主要来源于自然源,铅既有岩石和土壤风化产物硅酸盐矿物等自然源的贡献,又受到了人为活动的影响,银主要受人为活动的影响。聚类分析表明,可把莱州湾沉积物分为4类,其中黄河口西北缘沉积物中砷和镍污染生态风险最高,其次是莱州湾中部和北部。  相似文献   

14.
沈兰  范彪  田明  张璐  方福康  陈元晓 《海洋科学》2015,39(11):26-31
研究了滇池螺蛳(Margarya melanioides)分布和底泥营养成分之间的关系。2013年在滇池87个采样点采集螺蛳和底泥样本,图示分析所有采样点的活的螺蛳数量,确定活螺在滇池中的分布位点及分布密度;选择8个采样点的底泥样本,进行16项营养元素(有机质、磷、氮、锌、铁、锰、镁、钙、铜、钠、钾、砷、汞、铅、镉、铬)含量测定,分析这些样本营养元素的差异。根据这8个采样点中有无螺蛳生长,将8个底泥样本分为两组,采用完全随机设计两样本比较的t检验,结果两组样本间仅铜的含量有统计学差异(P0.05),这可能是由于滇池螺蛳的生长有效富集了重金属铜元素,使有螺区域比无螺区域底泥中铜的含量明显减少。这在一定程度上说明了螺蛳生长与底泥的关系,可为滇池污染防治及螺蛳种群保护提供相关的科学依据。  相似文献   

15.
深圳湾海域表层和柱样沉积物中的重金属分布特征   总被引:8,自引:1,他引:7  
分析深圳湾表层沉积物中锌、铬、镉、镍、铅、铜等6种重金属元素的含量发现它们的浓度均值已全部超过广东省海岸带沉积物背景值。根据潜在生态危害法,在6种重金属中镉造成的污染最严重,从潜在的生态危害指数评价看镉的含量已达到很高的污染水平。从面状分布看,重金属污染危害指数值在深圳河口区最低,在蛇口段居中等水平,在深圳湾内侧的近岸水域最大。柱样沉积物的浓度变化以1950年为界划分为两部分:1950年以来的现代沉积物中有较强的人类活动干扰痕迹,表现为重金属元素的浓度增长幅度大,且浓度很高,其均值全部大于广东省海岸带的背景值;1950年以前的近代沉积物中有稍弱的人类活动干扰痕迹。研究认为沉积物粒度特征、沉积速率、人类活动与重金属在沉积物中的浓度高低有直接相关关系,并直接影响到重金属在沉积物中的污染水平。  相似文献   

16.
To establish a base line against which future pollution may be measured, eight common commercial species of New Zealand sea fish were analysed for cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc. One sample of edible muscle tissue was analysed for each of 70 samples of each species. The internal organs of up to five specimens of each species were also analysed. The fish studied were: kahawai, Arripis trutta, trevally, Caranx lutescens, tarakihi, Cheilodactylis macropterus, snapper, Chrysophrys auratus, moki, Latridopsis ciliaris, hapuku, Polyprion oxygeneios, kingfish, Seriola grandis and gurnard, Trigla kumu.

Although, none of the edible parts of the fish appeared to have trace element levels likely to be a public health problem (cadmium 0.002–0.02 ppm, chromium 0.01–0.04 ppm, copper 0.04–0.95 ppm, iron 0.9–13.5 ppm, lead ‘ 0.14–0.95 ppm, manganese 0.04–2.00 ppm, nickel 0.01–0.08 ppm, zinc 2.0–36.0 ppm), some of the organs (particularly the liver) had relatively high concentrations of elements such as cadmium (up to 54 ppm). Only if some industry were to seek to exploit internal organs of fish for human consumption would such levels become important. There was some evidence for a relationship between trace element concentrations and fish size for copper in kingfish and snapper, iron in hapuku, manganese in gurnard, and for zinc in kingfish and tarakihi. Some element pairs such as copper and zinc, iron and manganese, appeared to have concentrations which were mutually related. It was assumed that the elemental concentrations reported represent natural levels and are not the result of significant man‐made pollution because there are no major industries or large urban centres adjacent to the fishing grounds.  相似文献   

17.
本文通过对太平洋 C C 区东区上覆水、间隙水、沉积物、结核中的环境参数、元素含量进行分析,研究了成矿元素在界面间(上覆水沉积物、间隙水沉积物、上覆水间隙水、沉积物结核)的迁移变化规律,为了解和揭示大洋多金属结核成因及成矿规律提供了依据。  相似文献   

18.
Weakly and strongly bound copper, lead and cadmium have been determined in the dissolved and particulate fractions of water samples from Oslofjord. The differentiation was made possible by using different sequences of filtration, acidification and digestion. The quantitative measurements were done by differential pulse anodic stripping voltammetry. Lead was found to be associated mostly with particulate matter, while cadmium was present only in the dissolved fraction. A strong digestion was needed for the determination of total metal. The advantage of pretreating sample bottles and filters with a conditioning solution is illustrated.  相似文献   

19.
近30a来长江口海域生态环境状况变化趋势分析   总被引:2,自引:1,他引:1  
杨颖  徐韧 《海洋科学》2015,39(10):101-107
在过去近30a监测结果基础上,对长江口海域生态环境变化趋势进行了分析。结果表明,近30a来,长江口海域水体中无机氮和活性磷酸盐呈现上升的趋势,重金属(铜、铅、镉和总汞)在一定范围内波动;浮游生物的种类数年际变化较大,浮游植物中硅藻比例有所下降,甲藻所占比例有所上升,浮游动物中桡足类的比例下降。讨论了长江径流输沙量与环境因子之间的相关性,发现硅酸盐的含量与输沙量呈显著正相关,且硅酸盐的减少与海域硅藻比例的减少具有一定相关性。长江口及其邻近海域环境与生态状况有所下降,特别是本世纪以来,海域的主要污染物仍为无机氮和活性磷酸盐,生物状态基本稳定在一个较低的水平上,近年来虽偶有波动,但没有明显改善的趋势。  相似文献   

20.
夏季珠江口沉积物中营养盐剖面分布和界面交换通量   总被引:21,自引:4,他引:21  
通过对夏季珠江口区域沉积物间隙水营养盐剖面分析,调查了营养盐含量分布和特征,探讨了有机物的降解特性、营养盐的底部通量估算和作用.结果表明,珠江口沉积物间隙水中营养盐以高含量铵盐为主要的存在形式,沉积物中有机物的降解反应主要在厌氧状态下进行,底部水体铵盐的增加来源于底部沉积物有机质的降解释放,而且对水体的营养盐循环有较大的贡献.  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