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1.
对2016年全年颗粒物监测浓度数据进行统计分析,得到了安徽省颗粒物污染的空间分布、浓度和粒径,以及污染传输特征。结果表明,淮河以北、沿江和江淮之间、长江以南和皖南山区城市颗粒物污染随地理位置不同表现出明显的区域化特征,污染程度由北向南减轻,污染过程明显表现出由北向南逐步扩散传输的规律,污染程度越重,污染深入南方的范围越广,持续时间也越长。冬季污染较重的城市,上午出现明显的高浓度时段,全天变化为"双峰双谷"型。夏、秋季节夜间细颗粒物(PM2.5)浓度贡献比增加。PM2.5与PM10(可吸入颗粒物)质量浓度比值冬季最高,春季较低。污染重的城市冬季PM2.5占比高。  相似文献   

2.
This paper presents the analysis and interpretation of ambient particulate matter concentrations measured as PM10 at a network of six air monitoring stations in Kathmandu valley during the years, 2003 through 2005. The purpose was to understand the pollution trends associated with different areas considering levels particulate matter concentrations representing the ambient air quality of Kathmandu valley. The study indicate that particulate concentrations (PM10) measured are persistently higher at air sampling sites representing roadside areas compared to the background sites. The inter-station network variability with respect the particulate pollution suggests optimizing resources. The comparison of annual average PM10 concentration observed at six air-monitoring sites in Kathmandu Valley with standard annual average concentration prescribed by World Health Organization as well as Europe Union indicates serious PM10 pollution in Kathmandu valley.  相似文献   

3.
北京市大气可吸入颗粒物的化学成分和来源   总被引:3,自引:0,他引:3  
2007年3月至2008年5月,在北京市成府路东口设立采样点,共采集监测周期为一周的PM2.5(直径小于2.5μm的大气可吸入颗粒物)样品56个,用HR-ICP-MS方法测量了15种元素的含量,并在此基础上应用主因子分析法对PM2.5中这些元素的来源进行探讨。同时,在2008年奥运会和残奥会期间开展了24h时间间隔的密集采样,特别分析了机动车限行期间细颗粒污染物的浓度特征。结果表明,2007年春季至2008年春季期间北京市大气PM2.5平均浓度为72.9μg/m3,超过美国环保局(USEPA)制定的PM2.5年平均浓度限值15μg/m3的近5倍。机动车限行期间北京成府路东口采样点大气PM2.5的平均浓度为40.7μg/m3。通过因子分析方法确定北京PM2.5的3种可能来源:①交通排放、工业排放和燃煤,特征元素为Cu、Zn、As、Sn、Sb、Cd、Pb;②本地扬尘和远源沙尘细颗粒;③可能与成土母岩风化有关的土壤颗粒的再悬浮和/或迁移,其方差贡献率分别为41.2%、31.4%和12.2%。  相似文献   

4.
于扬    岑况  NORRA Stefan    SCHLEICHER Nina  陈媛 《地质通报》2012,31(01):156-163
2007年3月至2008年5月,在北京市成府路东口设立采样点,共采集监测周期为一周的PM2.5(直径小于2.5μm的大气可吸入颗粒物)样品56个,用HR-ICP-MS方法测量了15种元素的含量,并在此基础上应用主因子分析法对PM2.5中这些元素的来源进行探讨。同时,在2008年奥运会和残奥会期间开展了24h时间间隔的密集采样,特别分析了机动车限行期间细颗粒污染物的浓度特征。结果表明,2007年春季至2008年春季期间北京市大气PM2.5平均浓度为72.9μg/m3,超过美国环保局(USEPA)制定的PM2.5年平均浓度限值15μg/m3的近5倍。机动车限行期间北京成府路东口采样点大气PM2.5的平均浓度为40.7μg/m3。通过因子分析方法确定北京PM2.5的3种可能来源:①交通排放、工业排放和燃煤,特征元素为Cu、Zn、As、Sn、Sb、Cd、Pb;②本地扬尘和远源沙尘细颗粒;③可能与成土母岩风化有关的土壤颗粒的再悬浮和/或迁移,其方差贡献率分别为41.2%、31.4%和12.2%。  相似文献   

5.
This paper presents a general, process-based model for suspended particulate matter (SPM) in defined coastal areas (the ecosystem scale). The model is based on ordinary differential equations and the calculation time (dt) is 1 month to reflect seasonal variations. The model has been tested using data from 17 Baltic coastal areas of different character and shown to predict mean monthly SPM-concentrations in water and Secchi depth (a measure of water clarity) very well (generally within the uncertainty bands given by the empirical data). The model is based on processes regulating inflow, outflow and internal fluxes. The separation between the surface-water layer and the deep-water layer is not done in the traditional manner from water temperature data but from sedimentological criteria (from the wave base which regulates where wind/wave-induced resuspension occurs). The model calculates the primary production of SPM (within the coastal areas), resuspension, sedimentation, mixing, mineralization and retention of SPM. The SPM-model is simple to apply in practice since all driving variables may be readily accessed from maps or regular monitoring programs. The model has also been extensively tested by means of sensitivity and uncertainty tests and the most important factor regulating model predictions of SPM-concentrations in coastal water is generally the value used for the SPM-concentration in the sea outside the given coastal area. The obligatory driving variables include four morphometric parameters (coastal area, section area, mean and maximum depth), latitude (to predict surface water and deep water temperatures, stratification and mixing), salinity, chlorophyll and the Secchi depth or SPM-concentration in the sea outside the given coastal area. Many of the structures in the model are general and could potentially be used for coastal areas other than those included in this study, e.g., for open coasts, estuaries or areas influenced by tidal variations.  相似文献   

6.
矿物颗粒是大气颗粒物的重要组成部分,其物相组成和微观形貌等特征既对人体危害的机理研究具有重要意义,同时蕴藏着颗粒物来源及变化等有用信息。自上个世纪80年代至今,大气颗粒物中矿物颗粒物相组成及微观形貌的研究大致经历了3个阶段,主要体现在研究方法和手段的不断探索与进步,研究对象由总悬浮颗粒向PM2.5甚至更细颗粒物以及由全颗粒分析向单颗粒分析转移,不断重视原生矿物变化及次生矿物生成机理研究。本文提出发生硫化现象的原生矿物及二次成因硫酸盐颗粒是未来研究的重要方向之一。  相似文献   

7.
This paper gives detailed comprehensive review of atmospheric assessment of particulate matter and heavy metals. Previous research works executed on this subject matter in the past four decades were adequately scrutinized. Various equipments for assessing atmospheric particulate matter and heavy metals were presented. Mathematical modeling equations for source apportionment and characterization, deposition rate prediction and health risk characterization of PM10 were also presented. However, the following conclusions were made: (1) there is need for improvement on the mathematical models by reducing the number of assumptions made in developing them. (2) Comparative analysis of concentrations of heavy metals in the atmosphere under the same environment for different methodologies should be executed for accuracy purposes. (3) Cost implication of assessing, monitoring and controlling these unfriendly substances should be examined, and hence, involvement of cost engineers may be of immense help. (4) Further research works should be done on Air-Q 2.2.3 model currently identified as a new methodology for provision of quantitative data on the impact of particulate matter exposure on the health of people. (5) Compliance monitoring networks should be designed to ease data collection for the observables, locations and time periods that allowed receptor models to be applied. (6) There is need for much more research works that enable optimal control and regulation of emission of heavy metals into the atmosphere in order to reduce health effects of these inhalable substances.  相似文献   

8.
The abundance of pyrite and other sulfide minerals in mine rock piles is a potentially significant if not a determinative factor in terms of the geochemical and geomechanical evolution of the dumps as oxidation produces acid solutions that drive hydrolysis reactions. A technique is presented here that supports the quantitative determination of pyrite abundance in mine rock dumps by heavy liquid mineral separation to concentrate pyrite for powder X-ray diffraction and then Rietveld method refinement of the diffraction data on a large number of samples using commonly available laboratory equipment. In order to improve and constrain the accuracy of XRD results, binary (pyrite-quartz) and 6-part mineral mixtures (pyrite and rock-forming andesite minerals) spanning a wide range of pyrite concentrations were prepared gravimetrically and run as standards. These standards were then used to minimize errors in pyrite abundance data by constraining key input parameters in the Rietveld refinement. A new polynomial relationship was derived between diffracting crystallite size and the Brindley microabsorption correction input size. This method provides a means to determine uncertainties in pyrite abundance, whereas conventional Rietveld refinement techniques done without the use of standards yield only statistical measures of the least-squares fit, rather than absolute uncertainties in mineral constituent weight percentages. The technique was applied to a number of mine rock pile samples and the uncertainty in the results determined by applying the relationship derived from the 6-part gravimetric standards to the results of the Brindley corrected Rietveld refinements. Uncertainties determined by this method are found to be on the order of ±10% for samples with pyrite content greater than 10 wt% and ±30% for samples with pyrite content less than 10 wt%. In order to evaluate the technique’s improvement upon traditional visual mineral abundance estimation the quantitative results are compared to manual volumetric estimates.  相似文献   

9.
Microscopic morphology and elemental composition of atmospheric particulate matter (PM) in 13 different size fractions from 0.01 to 10 μm were studied using a Field Emission Scanning Electron Microscope with Energy-Dispersive Spectrometer (FESEM–EDX). The relative mass fractions exhibited a bimodal distribution with a major mode in the fine range (0.18–1 μm) and a minor mode in the coarse range (>1 μm), suggesting that the major pollution of PM is fine particles in this area of Urumqi atmosphere. The PM could be classified as follows: aluminosilicate/silica mineral, Si–Al rich fly ash, Fe oxide particle, Ti dominant particle, sulfate/carbonate crystal, carbonaceous aerosols (including soot, organic carbon, tar ball and irregularly shaped carbon). The soot and organic carbon with anthropogenic sources are dominant types in fine range samples (<1 μm). The natural source minerals and secondary synthesized sulfate/carbonate crystals were accumulated in the coarse range (>1 μm). Elemental composition of various types of particles (0.056–5.6 μm) was also analyzed by EDX. C, S, O, N, Si, Al, Fe, Ca, Na, K, Mg, Cl, F, Hg were detected in most samples. Si, Al and Ca accumulated in coarse fractions, while S and Hg mainly accumulated in fine fractions. Concentrations of 15 metallic elements in size range from 0.1 μm to 5.6 μm were divided into three groups based on their possible sources. (1) The crustal elements (Al, Mg, Fe, Mn and V), mainly present in coarse particles (>1 μm); and (2) the anthropogenic source elements (Ca, Ni, As, Cu, Pb, Cd and Hg). The concentrations of Ca and Ni increased with increasing particle size, while As, Cu, Pb, Cd and Hg showed opposite trends. As, Cu, Pb, Cd and Hg accumulated mainly in fine fraction (<1 μm). (3) The multi sources elements (Cr, Co and Se) possibly come from both natural and anthropogenic sources. High levels of heavy metals, especially Hg in nanosize particles, may pose great risk to human health.  相似文献   

10.
Concentrations of Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Pb and Zn are measured in the atmospheric particulates from urban Islamabad, Pakistan during diurnal and nocturnal periods. On an average, the total suspended particulates and concentrations of Ca, Fe and Mg levels are considerably higher during day time and Cu concentrations are higher during night time. Significantly diverse correlations of elements are observed both during diurnal and nocturnal particulates. Multivariate principal component analysis reveals major anthropogenic contributions due to automobile emissions, combustion processes and industrial emissions. Enrichment factors show dominant anthropogenic contributions of Cd and Pb, followed by Co, Cu, Zn, Cr and Ca in diurnal and nocturnal atmospheric particulates. Comparison of metal concentrations observed in this study with those of previous studies from Islamabad and other urban areas around the world shows higher concentrations than those in some European cities but, in general, are lower than in large metropolitan cities.  相似文献   

11.
Air pollution has become a major problem in urban areas due to increasing industrialization and urbanization.In this study ambient concentrations of PM1 and metal concentrations as well as source contributions were identified and quantified by using Positive Matrix Factorization(PMF)in receptor modeling in the Metropolitan Area of Porto Alegre,Brazil.The PM1 samples were collected on PTFE filters from December 2012 to December 2014 in two sampling sites.Major ion and trace element concentrations were assessed.The average concentrations were 12.8 and 15.2μg/m3 for Canoas and Sapucaia do Sul sites,respectively.Major ion contributions of PM1 were secondary pollutants such as sulfate and nitrate.Trace elements,especially Cu,Pb,Zn,Cd,and Ni also made important contributions which are directly associated with anthropogenic contributions.Our results show significantly higher levels in winter than in summer.Most of the PM1 and the analyzed PM species and elements originated from anthropogenic sources,especially road traffic,combustion processes and industrial activities,which are grouped in 7 major contributing sources.A back-trajectory analysis showed that the long-range transport of pollutants was not relevant in relation to the contribution to PM1 and metal concentrations.This work highlights the importance of urban planning to reduce human health exposure to traffic and industrial emissions,combined with awareness-raising actions for citizens concerning the impact of indoor sources.  相似文献   

12.
《Applied Geochemistry》2006,21(7):1135-1151
Trace metal adsorption to suspended particulate matter (SPM) influences bioavailability and toxicity of trace metals in natural waters. For highly contaminated urban catchments in the greater Auckland (New Zealand) area, trace metal adsorption to SPM was assessed and compared to similar data from non-urban catchments in the Auckland region, to determine whether there was any difference in the ability of the SPM to adsorb Cu, Pb and Zn. The degree of trace metal adsorption onto the SPM was assessed by way of adsorption edge experiments. It was found that the ability of the Auckland urban SPM to adsorb trace metals decreased in the order Pb > Cu > Zn. Little difference in adsorption was observed between the non-urban Waikato and Kaipara River SPM and urban SPM, or between urban SPM from different flow regimes and seasons, despite some compositional differences in the SPM. This suggests that on the basis of a single surface-binding site, metal adsorption onto SPM could be readily predicted across a range of urban and non-urban catchments in the Auckland region. Adsorption edges were modelled with a diffuse layer, surface complexation model to assess the role of Fe-oxide in adsorption. The MINTEQA2 model was used, assuming Fe-oxide (as HFO) was the only adsorbing surface. There was generally good agreement between observed and modelled adsorption for Pb, indicating the importance of Fe-oxide surfaces for Pb adsorption. However, the model did not predict Zn or Cu adsorption as well. The TOC content of the SPM, and presence of dissolved ligands and organic matter in the water column, appeared to play an important role in Cu adsorption to the SPM. For Zn, the presence of adsorbing surfaces other than HFO appeared to influence adsorption.  相似文献   

13.
The occurrence and distribution of polycyclic musks in the Lippe River system (a tributary of the Rhine River, Germany) was investigated in order to observe the dynamic transport and partitioning of these compounds between aqueous and particulate phases after their discharge into the river by sewage effluents. 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzopyrane (HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), 6-acetyl-1,1,2,3,3,5-hexamethylindane (AHMI) and 4-acetyl-1,1-dimethyl-6-tert.-butylindane (ADBI) concentrations were determined in 19 water and surface sediment samples which were taken from a longitudinal section of the river. HHCB and AHTN were present in each of the water samples at concentrations ranging from <10 to 180 ng l−1 and <10 to 70 ng l−1, respectively. The load of dissolved HHCB and AHTN was calculated on the basis of compound concentrations in water and the corresponding river runoff data and ranged from 3 to 293 g day−1 and from 1 to 108 g day−1, respectively. Increasing loads of HHCB and AHTN along the river reflect a high input of sewage effluents to the densely populated areas along the central part of the river. Decreasing loads at the lower reaches indicate that in the corresponding river sections the rate of removal of musks was higher than the rate of input. Degradation and/or adsorption to particulate matter are processes that might explain this phenomenon. Consequently, high concentrations of HHCB and AHTN were detected in surface sediments from the Lippe River (from 5 to 191 μg kg−1 and from 2 to 1399 μg kg−1, respectively). HHCB/AHTN ratios in sediment samples were lower (average 1.2) than in water samples (average 2.9), suggesting the preferential adsorption of AHTN to particulate matter.  相似文献   

14.
大气颗粒物是大气质量评价中的一个通用的重要指标,近年来,对于大气颗粒物污染这一热点问题开展了大量的研究。文中选取辽宁省沈阳市、锦州市和葫芦岛市等典型地区研究大气颗粒物(TSP、PM10、PM2.5)中Cd等重金属元素的分布特征。结果表明,辽宁省大气可吸入颗粒物中Pb和Zn的含量最高,其次是Cu、Mn、As、Cr、Cd。燃煤、燃油和工业污染源等方面可能是造成这些元素含量较高的主要原因。此外,文中还对大气颗粒物对土地质量的影响研究进行一些有益尝试。研究表明,大气颗粒物中重金属元素含量对土地质量的影响是显而易见的。政府管理部门应该重视对大气颗粒物中重金属元素含量的监控,努力减少其对土地质量的影响。  相似文献   

15.
Experimental studies of the reactions of Cu(II), Pb(II), and Zn(II) in aqueous solutions with organic matter derived from fresh samples of the green filamentous algae Ulothrix spp. and the green unicellular algae Chlamydomonas spp. and Chlorella vulgaris show that, under suitable conditions, a significant proportion of the metals is removed from solution by sorption onto the particulate organic matter of the algal suspension.The metal sorption is strongly suppressed by H+ but is only marginally influenced by the proportion of whole cells in the suspension and by complexing of metals in solution by the soluble organic matter. The presence of relatively small amounts of the cations Na+ and Mg2+ in solution reduces the sorption of Zn(II) to near zero, but Pb(II) and Cu(II) sorption occurs to an appreciable extent even in strong brines. This may be a means for the selective precipitation of Pb(II) from brines rich in Pb(II) and Zn(II).Metal “saturation” values indicate that particulate algal matter of the type used in these experiments could sorb sufficient quantities of metal to form an ore deposit if a weight of organic matter of similar order of magnitude to that of the inorganic sediments in the deposits was available. However, the metal sorption is an equilibrium reaction, and the experimentally determined “enrichment factors” suggest that the “saturation” values could be approached only in solutions whose metal contents were initially at least two orders of magnitude above those of normal seawater.  相似文献   

16.
The major problems encountered in studying estuarine particulate organic matter (POM) are the characterization and quantitation of different kinds of materials (e.g. detrital and living matter, algal and bacterial matter…) each type contributing a specific role in the ecosystem. The study of the activity of the electron transport system (ETS) is proposed as a tool for resolving these problems. Results obtained in our laboratory with cultures of planktonic algae and bacteria provided us with numerical relationships between ETS activity and various organic components such as chlorophyll, carbon and protein. These relationships were: ETS activity/chlorophyll = 2.6, carbon/ETS activity = 17.3, protein/ETS activity = 9.6 in algae; carbon/ETS activity = 5.9, protein/ETS activity = 7.7 in bacteria (ETS activity expressed in /i2h−1 at 20°C; chlorophyll, carbon and protein in μg). Such data can be applied in field studies to characterize the living algal and bacterial matter and, by difference, the detrital organic matter. We report here a study of the Loire estuary as an example.  相似文献   

17.
张东旭 《矿产与地质》2016,(6):1024-1029
在广义Hoek-Brown强度准则中,如何量化地质强度指标GSI取值进而获得贴近工程岩体力学参数的问题,是众多专家学者一直在研究的课题.本文详细介绍了国内外专家对于此问题的最新研究成果,并提出了两个问题:各GSI取值方法的准确程度无法评价的问题;在改进的获取GSI表中,如何选取两个最具代表性的因素来表征岩体结构特征和岩体结构面特征的问题,这两个问题的研究将会推动岩体工程的进步.  相似文献   

18.
燃煤排放可吸入颗粒物的显微结构与物质组成研究   总被引:1,自引:0,他引:1  
对我国西南地区三个火电厂排放的可吸入颗粒物(PM10)的显微结构、矿物和化学组成等的研究表明,在PM10中,随着粒径的减小,非球形颗粒的比例增加;同原状飞灰相比,PM10以实心结构为主,多孔和空心结构较少;场发射扫描电子显微镜下,多数PM10颗粒的表面并不光滑,而是布满了次级微细颗粒;PM10的物相组成与燃煤煤种密切相关,小龙潭电厂PM10主要矿物包括石英、石灰、石膏和赤铁矿,而贵阳电厂PM10则以莫来石和石英为主;据单个PM10颗粒化学组成,将PM10分为硅质、铁质、Ca-铝硅质、Fe-铝硅质、Ca-Fe-铝硅质和硫酸钙六种颗粒类型;从不同采样点PM10元素组成看,从静电除尘器(ESP)前到ESP,PM10化学成分变化不大,到ESP后,元素Fe、Ca、Mg和Al的含量急剧减少,而Na的含量则迅速增高.  相似文献   

19.
 A high pressure neutron powder diffraction study of portlandite [Ca(OH)2] has been performed at ISIS facility (U.K.); nine spectra have been collected increasing the pressure by steps, up to 10.9 GPa, by means of a Paris-Edinburgh cell installed on the POLARIS diffractometer. The tensorial formalism of the lagrangian finite strain theory and the Birch-Murnaghan equation of state have been used to determine, independently, two values of the bulk modulus of portlandite, obtaining K 0=38.3(±1.1) GPa [linear incompressibilities: K 0a=188.4(±9.9), K 0c=64.5(±2.5) GPa] and K 0=34.2(±1.4) GPa, respectively. The present results comply with values from previous measurements by X-ray diffraction [K 0=37.8(±1.8) GPa] and Brillouin spectroscopy [K 0=31.7(±2.5) GPa]. Reasonably, Ca(OH)2 has revealed to be bulkly softer than Mg(OH)2 [K 0=41(±2), K 0a=313, K 0c=57 GPa]. The Ca(OH)2 linear incompressibility values reflect the nature of forces acting to stabilize the (001) layer structure and, further, prove that the replacement Ca/Mg mainly affects the elastic properties in the (001) plane, rather than along the [001] direction. Data from a full refinement of the structure at room pressure are reported. Received January 12, 1996/Revised, accepted June 15, 1996  相似文献   

20.
基于相干和方差体识别断层的方法都是利用地震资料中的强信号,受地震资料分辨率的限制这些方法对断距较小的小断层无法准确识别。在地震资料中大型地质体的边界具有明显的反射特征,尺度较小的地质体如尖灭点、小断层等以绕射波或残留绕射的形式存在,能量较弱,被强反射所淹没。本方法利用平面波破坏滤波技术提取绕射波信息,该技术通过正则化反演迭代算法求取反射波倾角体,然后利用均值滤波的方法得到反射能量较强的平面波,将其从地震数据中去除,即可得到绕射波信息。利用绕射波信息则可以判断断层的发育程度及断裂系统组合样式。通过理论模型分析和实际资料应用验证了该方法的可行性和有效性。该方法具有一定的实际应用价值。  相似文献   

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