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1.
Water quality assessment in the Aznalcollar area was attempted using multivariate methods based on heavy metal concentrations in red swamp crayfish (Procamburus clarkii). Trace levels of four heavy metals, copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb), were detected in crayfish from eleven different stations. Principal component analysis (PCA) highlighted a gradient of contamination between the sampling stations. Cluster analysis (CA) distinguished three groups of stations. Discriminant analysis also differentiated three groups. The group centroids of the first discriminant function were used to devise an index that varies according to the source of the crayfish. These standardized values are proposed for use as a water quality index. The ability of this index to successfully predict environmental quality was proved with random samples.  相似文献   

2.
Lake V?nern, the largest lake in Sweden, has been seriously contaminated with mercury during the 20th century. In the 1970's and 80's the direct load, mainly from a chlor-alkali industry in the area, of mercury was drastically reduced as a response to new legislation, from three to five tons down to between five and ten kg yr(-1). Large amounts of the disposed pollutant have accumulated in the sediments. The question posed in this work is now, is the effect of the drastic load reduction after more than two decades visible in the sediments? The question is relevant as large areas still are blacklisted for fishing, but also as a follow-up of a major remedy action. The lake also serves as a freshwater reservoir for even Sweden's second largest city. This work synthesises and compares data of mercury in the sediments from three major field programs, in 1974, 1984 and 1998. The interest is focused on both spatial heterogeneity and temporal trends. In 1974, the surface concentrations are significantly higher than in subsequent surveys. Significant differences are also found between 1984 and 1998. Significant spatial differences within the lake are found for respective year. The most contaminated area is located in the north, close to the major point source (a former chlor-alkali industry). This is also the area with the largest improvement, as a direct response to the reduction in load. Further from the outlet, the recovery is more affected by burial and transport processes out into the deeper basins.  相似文献   

3.
We studied the concentrations of certain heavy metals in the total and labile fractions of sandy sediments from four embayments situated on the northwestern coast of Spain. In orderto compensate for the effects of the heterogeneity in texture ofthe different samples, data were normalized. Organic carbon was the most suitable normalizing factor for copper, lead and zinc inthe total fraction and copper in the labile fraction, and iron was the most suitable for the other metals in both fractions.Enrichment of copper, lead and zinc in these sediments may have been caused by sewage contamination. The percentages of extractability for chromiun were remarkable.  相似文献   

4.
中国环境监测总站五年(1998—2002)纲要(摘要)   总被引:1,自引:0,他引:1  
1指导思想今后五年总站工作的指导思想是:高举邓小平理论的伟大旗帜,坚持实事求是的思想路线,以总局的五年工作纲要为指导,深化改革、夯实基础、健全功能、提高效能,站好四个中心的位置,当好环境监测队伍的“排头兵”,坚持为环境管理和各级监测站服务的方向,以说...  相似文献   

5.
6.
工程师部队负责具有重要经济价值的可航行水道、支流、河渠、连接运河等水域的水生植物蔓延的控制.这个职责是在水生植物控制计划办公室的总工程师领导下进行的,而现场操作由工程师部队地区办公室领导.水路实验站是工程师部队水生植物控制研究的领导实验室.这个计划的操作部分是各种水生植物控制手段和技术的实际应用.这些技术包括喷射化学药剂、使用生物和机械控制技术.该研究计划负责研制和传送现场操作单位极需要  相似文献   

7.
2.6溶出伏安法溶出伏安分析有较高的灵敏度,可达1×10~(-9)克/毫升。如果与差分脉冲极谱连用,测定下限可达1×10~(-12)克/毫升。2.6.1原理溶出伏安分析整个过程分为两个步骤.第一个步骤称为“电析”,即将欲测离子预先在一特定的恒电位下电解沉积,富集在静止汞滴(或悬汞滴)上或其它固体  相似文献   

8.
人们关心ICP-AES技术的最新进展,据Barnes教授谈,环绕六个方面:(1)试样导入方法的改进,(2)分析方法的途径;(3)解决光谱干扰;(4)改善信噪比;(5)改善机械装置发展仪器;(6)仪器系统造型和规范化。其实这六个方面是互相联系的,根据实际情况谈以下几个问题。 1.试样导入方法的改进。 试样导入一直是该技术的薄弱环节。Barnes最近一篇评论中说ICP-AES目前在试样导入中有三个难题。a.粗试样导入;b.光谱干扰、尤其是Al、Ca,Mg产生的  相似文献   

9.
2.伏安法 伏安法是研究在各种条件下电解时的电压与电流的关系。1922年捷克海洛夫斯基教授在研究毛细管电现象时,发明了极谱分析法。经过几十年的发展,先后出现了示波、方波与脉冲极谱法。溶出伏安技术,一般是与各种极谱法连用,分别可以提高灵敏度达几个数量级。伏安法是电分  相似文献   

10.
Trace metal concentrations of mercury, cadmium, lead and chromium in Patella caerulea, and Mullus barbatus were investigated to provide information on pollution of Ionian Sea, since these metals have the highest toxic potential. High chromium levels (0.47–0.97 g g–1 ww) were registered in limpet samples collected from two station near the Gulf of Taranto, while elevated concentration of mercury (0.31–1.50 g g–1 ww) were found in mullet specimens from Sicily. The metal concentrations recorded at the clean stations may be considered as useful background levels to which to refer for comparison within the Mediterranean area. On the contrary, the high levels of chromium and mercury found respectively in the areas near the Gulf of Taranto and at Capo Passero being of concern in terms of environmental health need frequent monitoring.  相似文献   

11.
广佛公路(盐步段)两侧挥发性有机物(VOC)污染研究   总被引:11,自引:3,他引:8  
选取广佛公路盐步路段作机动车尾气污染研究 ,结果表明 :污染物主要由烷烃、苯系物和氯代烃组成 ,主要是毒害性 VOC;污染随着与公路距离的增加而降低 ;污染源除机动车以外 ,还有大量的工业企业  相似文献   

12.
We investigated chlorinated hydrocarbon contaminants in aquatic mustelid species on the Fraser and Columbia Rivers of northwestern North America. Carcasses of river otter (Lutra canadensis) (N=24) and mink (Mustela vison) (N=34) were obtained from commercial trappers during the winters of 1990–91 and 1991–92. Pooled liver samples were analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), including non-ortho congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Most samples contained detectable concentrations of DDE, PCBs, although there was substantial variability in patterns and trends among neighboring samples. Concentrations of DDE were in some mink and several otter samples from the lower Columbia River elevated (to 4700 g/kg wet weight); excluding one mink sample from the Wenatchee area, mean DDE levels generally decreased between 1978–79 and 1990–92. PCBs were present in all samples. PCB concentrations in otter livers collected from the lower Columbia were ten-fold lower than measured a decade previously; nevertheless, a sample taken near Portland had a mean concentration of 1500 g/kg, within a range of concentrations associated with reproductive effects in captive mink. Concentrations of 2,3,7,8-TCDD and TCDF were generally below detection limits, except for one otter collected near a pulp mill at Castlegar, on the upper Columbia, with 11 ng TCDD/kg in liver. Elevated concentrations of higher chlorinated PCDD/Fs, probably resulting from use of chlorophenolic wood preservatives, were found in both species; one otter sample from the lower Columbia had 2200 ng OCDD/kg. International TCDD toxic equivalent levels in mink (31 ng/kg) and otter (93 ng/kg) from the lower Columbia River approached toxicity thresholds for effects on reproduction in ranch mink.  相似文献   

13.
Mercury (Hg) exposure was investigated through feathers of Olrog's Gull and related to health parameters in adults (hematocrit, total plasma proteins, morphometric measures, sex) and chicks (hematocrit, total plasma proteins, immunoglobulins G and M) from a colony located in estuary of Bahía Blanca, Argentina. Mercury concentrations were 5.50 ± 2.59 μg g?1 (n = 44) in live adults, 1.85 ± 0.45 μg g?1 (n = 45) in live chicks and 1.81 ± 0.41 μg g?1 (n = 41) in dead chicks. Large differences were observed between live adults and live or dead chicks and small differences between live and dead chicks. In the adults, the sex of the birds was the variable that best explained Hg concentrations. Male birds had higher concentrations than females; this suggests that the clutch provides a sink for mercury during egg laying. Hg concentrations in both adults and live chicks were associated with higher hematocrits. This could be associated with upregulated erythropoiesis to compensate for increased rate of destruction of prematurely senescent, Hg-contaminated erythrocytes. Based on our results, on the levels of Hg pollution in the past in the study area, and on the dietary specialization of Olrog's Gull, we must be vigilant about potential negative effects of Hg pollution on this population and recommend continued monitoring on this threatened species.  相似文献   

14.
The monitoring of dissolved zinc in the De?le river was undertaken at three different periods of the years 2008 and 2009. Electrolabile concentrations of Zn were estimated every 2 hours for several weeks by using an ATMS (Automatic Trace metal Monitoring System) based on voltammetric measurements using a solid Ag-Hg rotating disc working electrode. Complementary measurements were carried out with DGT (Diffusive Gradient in Thin films) pistons deployed directly in the river for 24 hours. Water samples filtrated at 0.45 μm were also analysed by HR-ICP-MS to estimate the total dissolved concentrations of zinc and other trace metals. High frequency monitoring of zinc over several weeks in the De?le river indicated that the concentration could change significantly over short time periods. Resuspension of polluted sediment and biological activities are two main factors that control the behaviour of zinc in the De?le river. Furthermore, in May 2009, daily cycles of the electrolabile zinc fraction have been observed at relatively constant total dissolved concentration. It is assumed that this particular behaviour of zinc is based on an exchange between colloids and/or nonelectrolabile forms and free cation and inorganic complexes at a daily time scale.  相似文献   

15.
通过对乌鲁木齐市的PM10和TSP数据的对比分析,找出PM10在TSP中所占比率(分担率)在采暖季和非采暖季的变化范围,从而使过去采集的TSP数据与PM10数据有一定的可比性,保证监测数据的连续可比。  相似文献   

16.
正环保部2016年7月8日向媒体发布了2016年6月全国和京津冀、长三角、珠三角区域及直辖市、省会城市、计划单列市空气质量状况。环境保护部环境监测司司长罗毅介绍,6月,74个城市中空气质量排名相对较差的后10位城市(从第74名到第65名)分别是:唐山、邢台、邯郸、济南、保定、郑州、太原、廊坊、衡水、北京和天津(北京、天津并列倒数第10位);空气质量排名相对较好的前10位城市依次是珠海、中山、海口、厦门、深圳、江门、舟山、惠州、南宁和丽水。  相似文献   

17.
氢化物发生—原子荧光法测定河水中硒(Ⅳ)硒(Ⅵ)   总被引:1,自引:0,他引:1  
在河水样品4mol/LHCl介质中硒生成氢化物,用氢化物发生法测定硒(Ⅳ)含量。将样品的4mol/LHCl溶液在沸水中加热还原硒(Ⅵ)至硒(Ⅳ)测定总量。总硒量减去硒(Ⅳ)量,分别求得硒(Ⅳ)和硒(Ⅵ)含量  相似文献   

18.
锌是周期表第二族的化学元素,元素符号为Zn,原子量为65.37,天然锌由质量数分别为64(48.89%)、 66(27.81%)、67(4.11%)、68(18.57%)、70(0.62%)的5种稳定同位素构成,九种放射性锌同位素中,Zn~(65)(半衰期为245天),Zn~(72)(半衰期为46.5小时)和Zn~(73)(半衰期为2分钟)最重  相似文献   

19.
持久性有机污染物的环境化学和生态毒理学是目前环境研究最活跃的领域之一。本文综述了持久性有机污染物的成分特性、对生物群的毒理效应、环境污染源、环境分析、环境行为、食物链传播、地区性或全球性的污染传输等问题。同时提出了对目前和将来持久性有机污染物研究的一些浅见。  相似文献   

20.
为检验PM_(2.5)和PM_(10)新监测标准实施近3年长沙大气颗粒物污染状况,利用近3年每日监测数据,对长沙10个国控自动监测点PM_(2.5)和PM_(10)达标情况、首要污染物及变化特征进行研究分析。结果表明,近3年长沙市PM_(2.5)和PM_(10)年均质量浓度均超过了新标准规定的年均值二级标准限值;2013年污染最严重。PM_(2.5)和PM_(10)月均值峰值出现在1月和11月,谷值在8月,各月PM_(2.5)超标天数和首要污染物为PM_(2.5)天数都大于PM_(10);PM_(2.5)和PM_(10)冬季日均值浓度明显高于其他季节,呈双峰型,峰值在上午10:00和20:00~21:00,夜晚浓度高于白天;PM_(2.5)春、夏、秋三季日变化呈单峰型,峰值在20:00~21:00;PM_(10)四季日变化呈双峰型。PM_(2.5)和PM_(10)浓度的比值(P)1月和2月最高,PM_(10)和PM_(2.5)日均值有着显著的线性相关性。  相似文献   

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