铜陵矿区水系沉积物中重金属存在形态特征研究   总被引：11，自引：0，他引：11  

张鑫  周涛发  袁峰  范裕 《地球科学进展》2004,(Z1)

通过对铜陵水系沉积物重金属形态分析实验,研究了重金属各种形态在沉积物中分布特征。分析结果显示,矿区水系沉积物中Cu、Pb、Zn、Cd等重金属含量都显著的高于对照样品,水系已经受到重金属的污染。提出了防治和改善铜陵地表水环境污染的措施。  相似文献   

Uranium pollution of South African streams – An overview of the situation in gold mining areas of the Witwatersrand     

F. Winde  L. A. Sandham 《GeoJournal》2004,61(2):131-149

During more than a century of gold mining in South Africa large amounts of tailings were produced, which now cover vast areas in densely populated regions. These dumps contain elevated levels of uranium and other toxic heavy metals associated with gold in the mined ore. Large-scale extraction of uranium from auriferous ore only took place during the cold war, leaving tailings with high uranium concentrations that were deposited before and after this period. Recent studies found elevated levels of the radioactive heavy metal in groundwater and streams, mainly attributed to the discharge of contaminated water from mines. In this paper the contribution of seepage from slimes dams to the uranium pollution of adjacent streams is analysed. Based on geochemical analyses of samples, field observations and long-term in situ measurements of hydraulic and hydrochemical parameters at selected mining sites across the Witwatersrand goldfields, the extent, mechanisms and dynamics of diffuse stream contamination by tailings seepage is characterised. Temporal and spatial variations of the process and the associated hazard potential are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

车载探测系统在近地面污染监测中的应用   总被引：2，自引：0，他引：2       下载免费PDF全文

魏强  赵增亮 《气象科技》2003,31(1):62-64,F003

文章介绍了车载粒子探测系统所使用的设备、显示分析软件以及2000年6月和12月在北京市城市污染大气探测中获取的数据。探测结果表明：北京市夏季和冬季近地面悬浮粒子浓度存在较大差异；同一季节北京城区及周边地区近地面悬浮粒子浓度存在较大差异；同一地区同一季节白天与黑夜存在较大差异。车载探测系统的观测试验表明：该套车载探测系统能连续记录近地面粒子尺度、汽车行驶轨迹和速度，其测量频率高，机动灵活，不受天气条件的影响；增加光阵探头个数，可以对0．1～9300．0μm的雾、气溶胶、雨和雪等粒子进行测量；可较好地应用于地面污染监测，同时还可用于云雾人工影响天气作业的地面监测。  相似文献   

北京市污染气溶胶散射特征实验及其数值模拟     

邓孺孺  田国良  孙荃  张力军  支毅乔 《遥感学报》2003,7(3):321-327

用地基遥感方法对北京市主要大气污染类型的气溶胶散射进行多角度观测实验，对比分析不同污染类型，及在不同观测角度下污染气溶胶的散射特征；并建立对各类型污染气溶胶散射率进行了数值模拟的数学模型。在此基础上求出观测时污染气溶胶的混浊度。为污染气溶胶的卫星遥感打下基础。  相似文献   

Regional Sources of Methyl Chloride, Chloroform and Dichloromethane Identified from AGAGE Observations at Cape Grim, Tasmania, 1998–2000     

M. L. Cox  G. A. Sturrock  P. J. Fraser  S. T. Siems  P. B. Krummel  S. O'Doherty 《Journal of Atmospheric Chemistry》2003,45(1):79-99

There are large uncertainties in identifying and quantifying the natural and anthropogenic sources of chloromethanes – methyl chloride (CH₃Cl), chloroform (CHCl₃) and dichloromethane (CH₂Cl₂), which are responsible for about 15% of the total chlorine in the stratosphere. We report two years of in situ observations of these species from the AGAGE (Advanced Global Atmospheric Gas Experiment) program at Cape Grim, Tasmania (41° S, 145° E). The average background levels of CH₃Cl, CHCl₃ and CH₂Cl₂ during 1998–2000 were 551± 8, 6.3± 0.2 and 8.9± 0.2 ppt (dry air mole fractions expressed in parts per 10¹²) respectively, with a two-year average amplitude of the seasonal cycles in background air of 25, 1.1 and 1.5 ppt respectively. The CH₃Cl and CHCl₃ records at Cape Grim show clear episodes of elevated mixing ratios up to 1300 ppt and 55 ppt respectively, which are highly correlated, suggesting common source(s). Trajectory analyses show that the sources of CH₃Cl and CHCl₃ that are responsible for these elevated observations are located in coastal-terrestrial and/or coastal-seawater regions in Tasmania and the south-eastern Australian mainland. Elevated levels of CH₂Cl₂ (up to 70 ppt above background) are associated mainly with emissions from the Melbourne/Port Phillip region, a large urban/industrial complex (population 3.5 million) 300 km north of Cape Grim.Now at the Centre for Atmospheric ChemistryNow at School of Environmental Sciences  相似文献   

Dispersion modelling of air pollution caused by road traffic using a Markov Chain–Monte Carlo model     

D. Oettl  R. A. Almbauer  P. J. Sturm  G. Pretterhofer 《Stochastic Environmental Research and Risk Assessment (SERRA)》2003,17(1-2):58-75

 Although the strict legislation regarding vehicle emissions in Europe (EURO 4, EURO 5) will lead to a remarkable reduction of emissions in the near future, traffic related air pollution still can be problematic due to a large increase of traffic in certain areas. Many dispersion models for line-sources have been developed to assess the impact of traffic on the air pollution levels near roads, which are in most cases based on the Gaussian equation. Previous studies gave evidence, that such kind of models tend to overestimate concentrations in low wind speed conditions or when the wind direction is almost parallel to the street orientation. This is of particular interest, since such conditions lead generally to the highest observed concentrations in the vicinity of streets. As many air quality directives impose limits on high percentiles of concentrations, it is important to have good estimates of these quantities in environmental assessment studies. The objective of this study is to evaluate a methodology for the computation of especially those high percentiles required by e.g. the EU daughter directive 99/30/EC (for instance the 99.8 percentile for NO₂). The model used in this investigation is a Markov Chain – Monte Carlo model to predict pollutant concentrations, which performs well in low wind conditions as is shown here. While usual Lagrangian models use deterministic time steps for the calculation of the turbulent velocities, the model presented here, uses random time steps from a Monte Carlo simulation and a Markov Chain simulation for the sequence of the turbulent velocities. This results in a physically better approach when modelling the dispersion in low wind speed conditions. When Lagrangian dispersion models are used for regulatory purposes, a meteorological pre-processor is necessary to obtain required input quantities like Monin-Obukhov length and friction velocity from routinely observed data. The model and the meteorological pre-processor applied here, were tested against field data taken near a major motorway south of Vienna. The methodology used is based on input parameters, which are also available in usual environmental assessment studies. Results reveal that the approach examined is useful and leads to reasonable concentration levels near motorways compared to observations. We wish to thank Andreas Schopper (Styrian Government) for providing air quality values, M. Kalina for providing the raw data of the air quality stations near the motorway and J. Kukkonen for providing the road site data set from the Finish Meteorological Institute (FMI). The study was partly funded by the Austrian science fund under the project P14075-TEC.  相似文献   

聊城市水质现状及对策     

李长青  杨兰华  唐浩 《地下水》2003,25(1):16-17,27

本文根据聊城市水量、水质、水污染的现状及2000年的水质监测资料中，主要污染的浓度、数量进行了分析，对如何解决这方面的问题提出解决的措施。  相似文献   

太原市兰村泉域地下水质量分析与对策   总被引：2，自引：0，他引：2  

孙磊 《地下水》2003,25(2):62-64,79

本文利用BP网络模型对兰村泉域地下水水质的污染程度进行了分析与评价，采用相关分析法对地下水中总硬度、Cl^—进行了预测，最后提出了对地下水污染的防治对策。  相似文献   

SARS流行期的天气学尺度分析   总被引：2，自引：0，他引：2       下载免费PDF全文

王铮  蔡砥  李山  杨妍  黎华群  毛可晶 《第四纪研究》2003,23(6):692-701

本文以香港和北京为例,对SARS流行期的天气特征做了事件相关分析和统计分析.研究发现,在SARS流行期,SARS疫情高发可能与大约8日前的气温日较差阶段性降低有关系.但是当气温日较差过程发生趋势性变化时,疫情过程的响应时间为5～10天.SARS疫情高发还可能与8日前空气相对湿度偏低有关系,同时也与11～12日前的相对湿度峰值有关.前者较多的表现在香港,后者较多表现在北京.初步认为,略低于相对湿度75%的某个值附近,相对湿度对于疫情发展有促进作用;相对湿度具有二重性.空气污染有助于SARS病毒的扩散传染,它的影响滞后期在8～10天.  相似文献   

拉萨市拉鲁湿地多环芳烃污染及其来源   总被引：9，自引：0，他引：9  

刘建华  祁士华  张干  张伟玲 《物探与化探》2003,27(6):490-492

通过分析采集的土壤、沉积物和大气样品,对拉萨郊区的拉鲁湿地多环芳烃污染及其来源进行了初步研究.湿地表层土壤中16种多环芳烃的平均含量的总含量为82.45×10^-9,既存在低环数的多环芳烃,又含有高环数的多环芳烃;湿地土壤中的多环芳烃主要来自于大气.  相似文献