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 78 毫秒
1.
为了更好的完成CNAL实验室能力验证工作,保证分析数据的精密性和准确性,文中从能力验证的作用、能力验证样品的特点及评价指标、能力验证样品分析中要注意的问题等几个方面论述了笔者参加能力验证样品分析工作一年来的一些切身体会.  相似文献   

2.
钻井废泥浆中重金属化学形态及潜在生态效应评价   总被引:2,自引:0,他引:2  
利用化学萃取法对江苏9个油田的不同类型钻井废泥浆的重金属化学形态分布特征进行调查分析,同时选用Hakanson的潜在生态危害指数法对钻井废泥浆中的重金属总量进行生态效应评价。结果表明,钻井废泥浆中Cu、Pb、Zn、Cd、Cr主要以残渣态和有机结合态为主,活性形态含量较低;采用Hakanson的潜在生态危害指数进行评价,发现Cu、Pb、Zn、Cd都属于轻微生态危害水平,而Cr多属于中等水平,产生潜在生态危害的重金属主要为Cr。  相似文献   

3.
主要报告了全国24个环境监测实验室利用气态苯系物标准样品开展实验室间测量比对研究的结果,并提出了一套结果比较的统计评价方法.  相似文献   

4.
环境监测数据是客观评价环境质量状况、反映污染治理成效、实施环境管理与决策的基本依据。为了进一步加强环境监测过程管理,有效提高环境监测数据质量,以列举法对影响生态环境监测机构数据质量的样品采集、运输、交接和实验室分析等监测活动的各环节进行了技术分析,梳理总结了数据质量技术判断的常见方法,旨在为环境管理部门开展监督管理提供经验借鉴。同时,就进一步提高生态环境监测机构的监测数据质量提出了建议。  相似文献   

5.
以国家重点生态功能区县域环境监测质量评价为目标,综合应用德尔菲法、层次分析法和模糊综合评价法,构建了国家重点生态功能区县域环境监测质量评价方法,并确定了评价因子、权重系数、计算方法。该方法评价指标共分为三层:第一层为目标层,即国家重点生态功能区县域环境监测质量;第二层为准则层,包括人员及资质、现场监测、实验室管理、报告编制及数据上报;第三层为方案层,包括人员操作、持证上岗、资质认定、人员培训、水质布点采样流转情况、空气自动站运维情况、现场质控实施情况、实验室环境条件、样品试剂的保存与管理、仪器检定与校准、实验室质量控制实施情况、数据填报软件运行情况、监测报告规范性等13个评价要素。经矩阵一致性检验确定了各评价要素的权重,将该权重与各要素得分运算后得到县域环境监测质量评价结果。在此基础上,选取广东、山西、陕西、四川和青海等5个省份的15个国家重点生态功能区县域作为典型区开展了实地调研,并应用评价体系对其进行了监测质量等级评价。结果表明,15个典型县域中,环境监测质量等级为优的县域占13.3%,一般、较差的县域分别占66.7%、20%。县域环境监测承担单位在资质、报告编制及数据上报方面表现较好,在现场监测、人员操作方面问题突出,在实验室管理方面有待提升。  相似文献   

6.
利用2012年松花江流域生物、生境和水质的调查数据,采用生物完整性指数(IBI)评价松花江流域的水生态环境质量,并着重对IBI评价结果与生境质量、水质间的关系及生物与生境和化学参数间的相关关系进行了分析。结果表明,松花江流域IBI评价结果与其生境质量存在显著正相关,与水质评价结果基本一致。生境质量及大多数生境参数均与多项生物参数间存在显著/极显著的相关关系;其次,COD、CODMn、BOD5、TN、TP等超标化学因子也与多项生物参数存在显著/极显著的相关关系,说明生境受损和有机污染压力是引起松花江流域水生态环境质量变化的主要压力。为恢复和改善松花江流域的水生态质量,研究建议针对流域生境质量和超标化学污染开展相应的保护和控制措施。  相似文献   

7.
提出了“合讲排序法”,运用该方法可以评价出实验室间样品考核排序名次,提高实验室质量控制水平。  相似文献   

8.
为研究湘江大源渡枢纽底泥中Cd、Pb的污染特征及其生态风险,采集6个断面的18个底泥样品,测定了沉积物中Cd、Pb的总量、化学形态及其生物有效性,并利用地积累指数法和单因子指数法评价其污染程度与等级.结果表明,湘江大源渡枢纽底泥中Cd、Pb存在很强的积累现象,尤其是Cd污染特别严重.各采样点底泥中Cd主要以碳酸盐结合态...  相似文献   

9.
为了解华东某市老城区潜层地下水硝酸盐分布特征,对老城区地下水现场采样,运用统计学软件spss中的Pearson相关系数和sufer软件Kriging插值方法分析数据,研究了无机氮与地球化学因素间的相关性,同时绘制了p H值、总硬度、硝酸盐、亚硝酸盐的空间分布图。结果表明,硝酸盐是该地区地下水中无机氮的主要存在形态,其所占总氮含量为45.5%~74.8%,封口井的硝酸盐的含量明显低于敞口井的含量,其硝酸盐所占比例最低达到2.2%,且敞口井均受到污染;从相关性的角度来看,氮的转化受到Fe影响较弱。同时氮的形态与p H值、矿化度(TDS)、电导率(EC)等地球化学因素相关水平显著;从分布特征来看,地下水环境中硝酸盐和亚硝酸盐含量东北部高于西南部;不同形态氮的相互转化影响地下水p H值和总硬度,致使p H值的高值区为西南部,而总硬度高值区为东北部。  相似文献   

10.
石墨炉原子吸收法测定水和废水中痕量铍的方法评价   总被引:1,自引:0,他引:1  
组织全国六个实验室对石墨炉原子吸收法测定水和废水中的铍进行方法验证。分析了统一标准样品、环境地面水和实验废水。以协作试验所得数据评价本方法的灵敏度、精密度、准确度和适用性。  相似文献   

11.
Determination of only total element in sediments does not give an accurate estimate of the likely environmental impacts. Speciation study of metals in sediment provides information on the potential availability of metals (toxic) to biota under various environmental conditions. In water, the toxic metal specie is the free hydrated metal ion. The toxicity of metals depends especially on their chemical forms rather than their total metal content. The present study focuses on Qaraaoun Reservoir, Lebanon. Earlier studies focused only on total metal concentrations in sediment and water. The objective of this study was to determine metal speciation (Fe, Cr, Ni, Zn, Cu, Pb, Cd) in the (operationally defined) sediment chemical fractions and metal speciation in reservoir water. This would reflect on metal bioavailability and toxicity. Water samples and bed sediments were collected from nine sites during the dry season and a sequential chemical fraction scheme was applied to the <75-??m sieve sediment fraction. Metal content in each fraction was determined by the FAAS technique. The data showed that the highest percentages of total metal content in sediment fractions were for: Fe in residual followed by reducible, Cr and Ni in residual and in reducible, Cu in organic followed by exchangeable, Zn in residual and in organic, Pb in organic and carbonate, Cd was mainly in carbonate. Total metal content in water was determined by ICP-MS technique and aqueous metal speciation was predicted using AQUACHEM software interfaced to PHREEQC geochemical computer model. The water speciation data predicted that a high percentage of Pb and Ni were present as carbonate complex species and low percentages as free hydrated ions, highest percentage of Zn as carbonate complex species followed by free hydrated ion, highest percentage of Cd as free hydrated ion followed by carbonate complex species. The sensitivity attempt of free hydrated ion of Ni, Zn, Pb, and Cd in reservoir water revealed dependence of Zn and Cd on pH and alkalinity, while Ni and Pb were only dependent on pH.  相似文献   

12.
An analysis of the geochemical distribution of selected trace metals among various geochemical phases of the sediments in the Tees estuary was carried out using a sequential extraction technique and Differential Stripping Voltammetry. The sediments of the estuary are mainly organic rich clay silts and metal concentrations exceed those in the water column. Speciation results show that contamination of the estuary is mainly from anthropogenic sources. Pb and Zn are associated with the reducible, residual and oxidisable fractions. The speciation pattern of Cd was similar to those of lead and zinc. However there were also some exchangeable and bound to carbonate fractions although these were less significant. Cu is largely associated with the oxidisable and residual fractions, with insignificant bound to carbonate, exchangeable and reducible fractions. The most bioavailable forms of the metals are the free inorganic ions. Total metal concentrations in the estuary display a downward trend since the 1970s.  相似文献   

13.
A long-term study of the effect of artificial aeration (destratification) of a water storage dam upon the speciation of iron and manganese in the dam waters has been undertaken. Separation of dam samples into soluble and insoluble forms by selective membrane filtration was undertaken before using the techniques of EPR spectroscopy, ion chromatography and gel filtration to assess the speciation of soluble species, and selective extraction and surface analysis (ESCA, SIMS and SEM) techniques to determine the speciation of particulate iron and manganese species. The percentages of soluble iron and manganese before (1983–85) and after (1986–88) artificial aeration are compared for the periods Jan–Dec, Jan–Mar, and Jun–Aug at three depths 6 m, 15 m and 0.5 m above the dam base, to assess the importance of seasonal changes in the various depths of the dam. Although aeration had an initial marked reduction in levels of soluble iron and manganese at all depths of the dam, the concentrations of these mtals showed a steady increase over succeeding years. Analysis of the figures over summer and winter periods shows that the reduction of soluble iron was maintained in summer, but not during winter. Upon aeration, the initial reduction of soluble manganese concentration was maintained in succeeding years in the epilimnic regions of the dam, but not in the hypolimnion. Statistical analysis of data has been undertaken to correlate the changes in relationship between the various forms of iron and manganese with the advent of aeration.  相似文献   

14.
Geochemistry in the modern soil survey program   总被引:1,自引:0,他引:1  
Elemental analysis has played an important role in the characterization of soils since inception of the soil survey in the US. Recent efforts in analysis of trace and major elements (geochemistry) have provided necessary data to soil survey users in a variety of areas. The first part of this paper provides a brief overview of elemental sources, forms, mobility, and bioavailability; critical aspects important to users of soil survey geochemical data for appropriate use and interpretations. Examples are provided based on data gathered as part of the US soil survey program. The second part addresses the organization of sample collection in soil survey and how soil surveys are ideally suited as a sampling strategy for soil geochemical studies. Geochemistry is functional in characterization of soil types, determining soil processes, ecological evaluation, or issues related to soil quality and health, such as evaluating suitability of soils for urban or agricultural land use. Applications of geochemistry are on-going across the US and are documented herein. This analytical direction of soil survey complements historic efforts of the National Cooperative Soil Survey Program and addresses the increasing need of soil survey users for data that assists in understanding the influence of human activities on soil properties.  相似文献   

15.
土壤重金属污染生态风险评价方法综述   总被引:15,自引:1,他引:15       下载免费PDF全文
生态风险评价是风险论与生态学、环境科学、地学等多种学科相互交叉的边缘学科.以土壤生态系统为对象,介绍了目前已有的几类重金属污染生态风险评价方法,包括概念模型法、数学模型法、指数法、形态分析法、植物培养法等.指出根据研究目的与污染特性选择适当的评价方法,可以为土壤生态风险管理提供科学信息.  相似文献   

16.
植物内重金属分析不仅有助于阐述重金属迁移转化规律,揭示植物修复机理,也是监测评价大气、水及土壤环境重金属污染状况的重要依据。研究针对植物样品中重金属赋存形态及分布特征的分析方法进行综述,分别介绍了其原理、优缺点及应用。提出制定统一高效的分析检测方法,深化植物内重金属的赋存形态及分布特征与环境相关性的研究以及建立数据共享平台是植物样品重金属信息分析方法的未来发展方向。  相似文献   

17.
Since 1975, the British Columbia Ministry of Forests has been systematically developing an ecosystem classification of the province, an area covering 94 million hectares. This Biogeoclimatic Ecosystem Classification (BEC) system provides a framework for resource conservation and management. To date, approximately 250 person-years have been invested in the collection, analysis and synthesis of over 8000 ecological (vegetation and environmental data) plots, and in the production of ecological field guides.The development of a database and analysis system on the micro-computer platform to support a classification system of this magnitude was a complex procedure that required judicious planning and coordination. We have developed data-processing software that permits a user to select raw data from broad provincial or regional coverage to plot- and species-level summaries, and to export the data to a variety of output formats.This paper addresses key issues for handling ecological field data on the desktop computer with emphasis on standards, operator ease-of-use, and data access.  相似文献   

18.
Methodologies for the environmental analysis of total antimony and aqueous chemical speciation are critically reviewed, including preparation techniques for aqueous and solid matrices and the determination of solid state partitioning and recommendations are given for future research directions. Concentrations of total antimony commonly present in aqueous and solid environmental samples are readily determined using present day analytical techniques. This has resulted primarily from technological advances in microwave digestion for solid matrices and the development of plasma based analyte detection systems. ICP-AES and ICP-MS techniques are both utilised for the environmental analysis of total antimony concentrations. However, ICP-MS is increasingly favoured as a result of reduced spectral interferences and the potential for analyte detection in the pg mL(-1) range. Determination of aqueous antimony speciation presents a number of complex analytical challenges and highly selective separation and identification techniques are required prior to detection. The majority of published techniques including common applications of hydride generation are insufficiently selective for the determination of intrinsic chemical speciation and often only oxidation state data are obtained. The recent in-line applications of HPLC-ICP-MS offer the potential for highly selective separations of aqueous antimony species and determination of detailed chemical speciation data. However, considerable development work is required to optimise chromatographic separations and identify uncharacterised species resident in environmental systems. Analytical techniques to aid the determination of antimony's associations with solid environmental matrices include the application of chemical extraction procedures and leaching experiments. To date, this area of analytical research has received little attention and further studies are required to elucidate this aspect of antimony's environmental chemistry.  相似文献   

19.
A nation-wide ecosystem science network for Canada was formed in 1994. At that time, mercury was a re-emerging issue in Canada and the Coordinating Office for the networksought collaboration to assess the issue. The key mechanismsby which the network has added value in addressing this issue are: 1) Information Dissemination, the network has organised, facilitated and co-hosted a number of regional,national and international mercury events (meetings, conferences and workshops) which have served to bring theexpertise together, the network also disseminates informationon it's web page, and the Coordinating Office hosts an annualNational Science Conference; 2) Collaborative Mercury Monitoring, network partners advocated the need for a singlehemispheric mercury network which resulted in the developmentof a compatible Canada–U.S. mercury deposition network, whichmay also be expanded into Mexico, and 3) Environmental Reporting, the network has collaborated with others to reporton current mercury findings through initiatives such as the 1998 Northeast States and Eastern Canadian Mercury Study, a 1999 Mercury Case Study and is presently a partner in the University of Quebec's proposal to form a Collaborative Mercury Ecosystem Research Network in Canada.  相似文献   

20.
The introduction of catalytic converters has led to a new environmental problem since catalysts emit platinum group elements (PGEs) which are among the least distributed elements in nature. Along with PGEs the vehicle exhaust catalysts contain also a number of stabilizers, commonly oxides of rare earth elements and alkaline earth elements such as Ce, La and Zr. Since vehicular emission of these elements has received little attention so far this work attempts to offer insight into their distribution and fate in the environment by measuring their speciation in road dust samples collected along several highways in Germany and a city centre (Saarbrücken). Speciation of the elements (fractionation into associated mineralogical phases) was carried out via a conventional sequential extraction protocol and the complexing abilities of humic substances in the organic matter were investigated by selective extraction methods in combination with size segregation. For evaluation purposes soil samples spiked with catalytic converter material were analyzed, showing a much lower fraction of Ce, La and Zr mobilized in comparison to the road dust samples. It was found that the elements were effectively bound to humic substances in road dust with a preference for complexation with low molecular weight compounds (<1600 Da).  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