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1.
天津市土壤风沙尘元素的分布特征和来源研究   总被引:8,自引:0,他引:8  
通过与土壤标准和背景值的比较分析了天津市土壤风沙尘元素的质量分数分布特征,通过富集因子法分析了天津市风沙尘元素的富集特征,进而说明天津市风沙尘元素的来源及其变化。结果表明,(1)Cr、Ni、Cu、Zn和As质量分数均有超过土壤标准的现象。(2)Ni、Cu、Pb、Zn和Ag超过背景值10倍以上,受到了人为污染。(3)粗颗粒中西青区的Pb元素,津南区的Ni元素和Pb元素以及细颗粒中东丽区的Ca元素和Zn元素,西青区的Cu、Pb,津南区的Cr、Ni、Pb等元素达到显著污染级别;各区粗细颗粒中的Ag元素污染级别最高,有的为极强烈污染;这些元素是典型的人为污染元素。(4)粗颗粒中只有Ca和Ni污染级别有所增加,细颗粒中只有Na、Ni、As等3种元素的富集因子略有增加。所以,天津市土壤风沙尘的治理重在控制人为来源的Ni、Cu、Pb、Zn、Ag、Cr和Ca等高污染元素。  相似文献   

2.
大气气溶胶对健康、环境和气候具有重要影响,研究其理化特征能阐明灰霾的成因及机理,对科学调控大气环境具有重要意义。以广东江门鹤山大气超级监测站为观测平台,使用单颗粒气溶胶质谱仪(SPAMS)和气团后向轨迹综合分析了单颗粒气溶胶的理化特征,揭示了气团轨迹对颗粒物浓度、类型和化学成分的影响。单颗粒气溶胶质谱仪在2012年5月11日至7月31日,共采集了约600万个同时含有粒径和质谱信息的颗粒,它们主要可分为8类:有机碳颗粒(OC)、元素碳颗粒(EC)、元素-有机碳混合颗粒(ECOC)、富钾颗粒(K-rich)、大分子有机碳颗粒(HMOC)、海盐颗粒(Na-K)、金属颗粒(Metal)和富硅颗粒(Si-rich)。各类颗粒的质谱特征在一定程度上反映了颗粒的来源:EC颗粒来自一次污染源;K-rich颗粒主要来自与生物质燃烧有关的过程;Na-K颗粒来自于海盐碎沫;Metal颗粒主要来自工业源或火力发电;Si-rich颗粒则主要来自扬尘。8类颗粒中普遍存在的二次成分表明它们都经历了一定程度的大气老化过程。采样期间每隔6h绘制一条气团后向轨迹图,聚类分析发现这些气团后向轨迹主要有5类:第1类占总轨迹数的14.1%,它代表由内陆经广州、佛山到达采样点的气团;第2类占总轨迹数的10.2%,它代表沿东南部大陆海岸线到达采样点的气团;第3类和第5类在气团后向轨迹中占的比例最高,分别为30.0%和36.8%,它们都来自南海海面,但第3类气团经珠海、澳门到达采样点,而第5类则经阳江到达采样点;第4类占总轨迹数的8.8%,这类气团途经深圳、东莞到达采样点。单颗粒数据结合气团后向轨迹进行统计分析表明:经广州、佛山到达采样点的气团会带来高浓度的颗粒物污染,且颗粒的老化程度较高,而发源于南海海面的气团能带来新鲜海风,对鹤山的大气污染起稀释作用;在颗粒类别上,途经广州、佛山、东莞、深圳这些重污染城市的气团中EC颗粒和ECOC颗粒的含量更高,而途经珠三角南部区域的气团则含有更多的OC颗粒和Metal颗粒。  相似文献   

3.
典型背景点降水化学组份的分析   总被引:7,自引:0,他引:7  
刘嘉麒  洪峪森 《环境化学》1996,15(5):391-398
全球背景降水划分为海洋型,内陆型和海洋与内陆相间型三种,以太平洋的Amsterdam和大西洋的S;Georges为例,研究海洋型背景降水受海洋大气环流控制,化学组分来源于海洋气溶胶。分析了澳大利亚Katherine海洋与内陆相间型,背景降水化学组份来主要来源于海洋气溶胶和内陆大气污染传输两者的相关性。  相似文献   

4.
扫描电镜和X射线能谱法研究沈阳地区气溶胶颗粒的特性   总被引:5,自引:3,他引:2  
本文提供了一种以玻璃态石墨为衬底,静电采样器采样,对气溶胶颗粒直接进行扫描电镜观察和X射线能谱分析的方法。通过对沈阳地区收集的大量气溶胶颗粒的观察和分析,发现亚微米颗粒近似球状,以硫氧化物为主要成份,含少量二氧化硅,可认为是二氧化硫的转化产物在细微的二氧化硅或硅酸盐上凝聚而成;微米颗粒呈不规则形状,以硅酸盐为基本成份,吸附少量二氧化硫的转化物,并普遍含铝、铁、镁、钙等地壳元素,其来源为风化的岩石粉尘。其它人为产生的污染元素主要存在于微米颗粒中。  相似文献   

5.
纳米材料的环境行为和生态效应是目前国内外研究的热点,其中纳米银颗粒(Ag NPs)是使用量最高的纳米材料。本文主要总结了Ag NPs在水环境中的赋存、Ag NPs的环境行为、Ag NPs对不同种类微生物的毒性效应以及影响Ag NPs毒性效应的因素,最后对Ag NPs在河口区的研究进行了展望。  相似文献   

6.
为了解广州地区灰霾天气成因及污染特征,更好地为保障空气质量提供基础数据和科技支撑,利用单颗粒气溶胶质谱仪(SPAMS)研究了广州市秋季(2013年9月26日─10月10日)灰霾生消过程中大气气溶胶单颗粒组成特征。根据空气质量将观测时段划分为优良、轻度污染和重度污染3种类型,并对颗粒物化学组成的变化过程进行分析。研究结果表明,大气颗粒物类型主要可分为8种:元素碳颗粒(EC)、有机碳颗粒(OC)、元素碳有机碳混合颗粒(ECOC)、大分子有机碳颗粒(HOC)、富钾颗粒(K-rich)、左旋葡聚糖颗粒(LEV)、重金属颗粒(HM)和富硅酸盐颗粒(SI),这8种颗粒类型占了监测期间总颗粒的96%。重度污染天气下,从颗粒物平均质谱图来看,颗粒中含有的二次离子(硫酸盐和铵盐)相对于优良天气明显升高;从成分类别来看,富钾颗粒比例从15.1%增加到58.3%,说明来自生物质燃烧一次源的比例大幅增加,结合风速变化推断,灰霾发生的原因主要是由于气象扩散条件不利(平均风速小于3 m·s~(-1)),来自生物质燃烧的颗粒物持续积累,同时二次反应导致气溶胶颗粒更加老化。  相似文献   

7.
大气沉降是室内灰尘的重要来源.本研究于2017年1—2月采集了河南省12个城市的室内灰尘样品共48个,并按照取样城市的空间分布探讨了重金属(Ni、Cu、Zn、Mn、Co、Cr、As、Ag、Cd、Pb)污染的南北差异(以黄河为界).运用地积累指数法对其进行污染评价.应用美国EPA人体暴露风险模型进行健康风险评价.结果表明,豫南城市室内灰尘中重金属除Pb以外平均浓度均显著高于豫北城市.豫南城市重金属平均浓度表现为Zn Mn Cr Ni Pb As Cu Co Cd Ag,浓度大小依次是306.7、249.2、223.3、116.9、55.7、41.6、30.3、7.0、1.8、1.3 mg·kg-1,而豫北城市重金属浓度表现为Zn Mn Pb Cr As Ni Cu Co Cd Ag,浓度大小依次是200.7、179.4、85.4、48.7、22.9、22.1、21.4、4.4、2.6、0.7 mg·kg-1.地累积指数结果显示Cd在豫南和豫北城市均是重污染和极重污染,而Ag在豫南城市是重污染和极重污染.豫南城市室内灰尘中4种致癌重金属的致癌风险大小依次为Cr As Ni Cd,6种非致癌重金属的非致癌风险大小依次为Zn Mn Cu Pb Co Ag;豫北城市室内灰尘中致癌重金属的致癌风险依次为Cr As Ni Cd,非致癌重金属的非致癌风险依次为ZnMn Pb Cu Co Ag.  相似文献   

8.
北京大气气溶胶单个颗粒的化学表征   总被引:37,自引:1,他引:37  
汪安璞  沙因 《环境化学》1996,15(6):488-495
用安德逊分级采样器采集京都三个点(北辛安,冷泉村和生态环境研究中心)的大气气溶胶颗粒,用扫描电镜/X射线能谱观察和分析单个颗粒的形貌和元素成分,对粗细颗粒分别进行了X射线物相分析,通过对颗粒的形貌,组分和化合物形态等的综合分析结果表明,细粒样品中常含有较多的铁或铵的硫酸盐及氯化铵,粗粒样品中则主要为矿物物质如石英,方解石,石膏,白云石和一些粘土矿物,圆形颗粒可能是煤的燃烧产物,许多不规则形的颗粒大  相似文献   

9.
为了从单颗粒角度了解沙尘天气颗粒物特征和来源,利用单颗粒气溶胶飞行时间质谱仪(SPAMS)对张家口市2016年春季一次沙尘天气期间的气溶胶颗粒进行了化学组分、粒径分布和来源的分析。根据颗粒的质谱图特征,将其分为沙尘(Dust)和非沙尘(Non-dust)颗粒两大类,两者占比分别为12.9%和87.1%。Dust颗粒粒径主要分布在0.5~1.1μm,包含沙尘-铝(Dust-Al)、沙尘-硅(Dust-Si)、沙尘-金属(Dust-metal)、沙尘-钙(Dust-Ca)颗粒4个主要子类别,比例均超过20%,表现出明显的矿尘颗粒特征。非沙尘类颗粒分布在0.4~0.8μm粒径段,包含4个子类别:含碳(Carbonaceous)、富钾(K-rich)、工业金属(Industrial Metal)和其他颗粒(Other)。结合后向轨迹分析,沙尘颗粒可能主要来自新疆、蒙古、内蒙古等地区的沙尘源,少部分来自当地、山西等地的矿尘源、工业源;非沙尘颗粒可能主要来自当地及周边地区工业排放和燃煤;Dust颗粒的NO_3~-/HSO_4~-(颗粒数)比值为1.31,颗粒老化程度较高。含Cl的Dust颗粒物占比为32%,说明颗粒中混有人为组分。研究结果表明SPAMS可用于沙尘天气颗粒物理化特征和来源的在线分析,可为沙尘防治提供参考信息。  相似文献   

10.
肖辉林 《生态环境》2004,13(1):33-33
由人类活动产生的气溶胶(空气中微小的颗粒状污染物,是烟雾污染的主要成分)可通过增加云中液滴的数量来增强云的反射率。很多小液滴与较少的大液滴相比,可将更多的阳光反射进太空,所以理论上气溶胶颗粒的积聚可产生变冷效应,被称为“间接气溶胶效应”。“政府间气候变化小组”(IPCC)曾经得出结论认为,气溶胶的间接效应也许是可以忽略的。得出此结论,部分是由于缺乏这种机制影响进入云层的太阳辐射和流出云层的红外辐射之间的平衡的直接证据。来自被污染地点(美国俄克拉荷马)和干净地点(美国阿拉斯加)的空气的新数据表明,气溶胶污染物显著…  相似文献   

11.
We report for the first time the distribution and hazard potential of aerosol and metals resulting from joss paper burning. Burning joss paper and incense is a traditional custom in many Oriental countries. Large amounts of air pollutants, including particles, polycyclic aromatic hydrocarbons, toxic metals and other gaseous pollutants, are released into the environment during the burning stage. Many investigations have reported on the emission of pollutants from the incense burning. However, no work has been reported until now on the analysis of the released pollutants apart from polycyclic aromatic hydrocarbons. In this study, a micro-orifice uniform-deposit impactor and inductively coupled plasma optical emission spectrometry were, respectively, used to collect aerosols and characterize the toxic metals from joss paper burning. We studied two types of particulate matter (PM): PM2.5 that are particles with a diameter smaller than 2.5 μm and PM10 that are particles with a diameter smaller than 10 μm. PM2.5 are the most potentially toxic particles. Our results showed that PM2.5 are the major component of the pollutants and that the PM2.5 to PM10 ratio ranged from 62 to 99%. The metals Na, Ca, Mg, Al and K were the main species in the aerosol and in the bottom ash.  相似文献   

12.
用核子微探针进行单个大气颗粒物的分析   总被引:7,自引:1,他引:7  
沙因  谷英梅 《环境化学》1995,14(6):518-523
本文对单个大气颗粒物进行了分析研究,用核子微探针对首钢地区单个大气颗粒物进行了扫描分析,用三维等高线法给出了各种元素在一群单个大气颗粒物中的二维分布。从一群单个大气颗粒物中各元素的二维分布可对首钢地区大气污染的特征及来源进行分析研究。  相似文献   

13.
用扫描电镜分析表征大气气溶胶单颗粒   总被引:6,自引:0,他引:6  
1 IntroductionAtmosphericaerosolsarecomplexmixture,originatedfromavarietyofsources.Mostoftheanalyticaltechniquesusedforitscharacterizationarebulkmethodsthatgenerateonesetofdatapersample,describingtheoverallcompositionofthesample .Toworkoutusefulinformationonpollu tionsources,itrequiresdataofagreatnumberofsamplesandmultivariatedataanalysismethodsusuallyareneeded .Ontheotherhand ,scanningelectronmicroscope energydispersiveX rayanaly sissystem (SEM EDX)isabletoprovideanalyticaldataforeachsing…  相似文献   

14.
Scanning electron microscopy with energy-dispersive spectroscopy has been used for both morphological and elemental chemistry analyses of atmospheric particles. This technique allows the in situ observation of individual aerosol particles in the sample chamber. Aerotransported particles were analysed from seven monitoring stations located in the Metropolitan Zone of Toluca Valley (MZTV). Several different morphologies were identified: aggregates, porous spheres, rough and smooth compact material. The elemental composition included C, Na, Mg, Al, Si, S, Cl, K, Mn, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn and Ce. These are semiquantitative analyses considering the bulk sample or individual particles. It was possible to correlate or confirm some chemical associations such as C–S, Ca–S–O and Si–Al–O, probably due to the presence of compounds derived from incomplete combustion, building tailing materials and aluminosilicates of cortical origin. Bioaerosols such as pollen, spores, brochosomes and diatoms were identified in the zone; all these types of particles have a natural origin too. Several types of suspended particles were identified in the MZTV, they were from different sources (natural and anthropogenic) to which the population can be potentially exposed, and may cause harm in the short- and long-term, according to their chemical element composition and size.  相似文献   

15.
武汉市城区大气PM2.5的碳组分与源解析   总被引:2,自引:0,他引:2  
大气细颗粒物(PM2.5)和碳组分(OC,EC)是影响大气能见度、气候变化以及人体健康的重要污染物,研究大气颗粒物及其中碳组分的污染特征及各类典型污染源对大气细颗粒物及碳组分的贡献,对于认识区域和城市大气污染状况,控制细颗粒物的污染,具有重要意义。2011年7月至2012年2月,利用大流量PM2.5采样器采集武汉市大气细颗粒物样品并对其碳组分进行测定。武汉市城区大气中PM215、OC和EC的质量浓度平均值分别为(127±48.7)、(19.4±10.5)和(2.9±1.48)μg·m-3。其PM2.5的浓度处于我国主要城市的中等偏高水平,而OC、EC的浓度则属中等偏下水平,但均高于国外城市。武汉市大气PM2,质量浓度的季节性变化呈现出秋季〉冬季〉夏季的趋势,是气象因素和污染源排放综合影响的结果。OC浓度和EC浓度具有较好的相关性(r2=0.69),表明二者存在来源联系。OC/EC的比值为6.7,指示武汉市大气中OC和EC的来源受汽车尾气排放和生物质燃烧的共同影响。SOA的平均质量浓度值为12.5μg·m-3约占PM2.5平均质量浓度的9.8%,表明SOA对武汉市城区大气PM2.5具有重要贡献。结合PM2.5所含的水溶性离子、微量元素组成,利用正矩阵因子分析(PMF)模型对武汉市城区大气PM2.5来源进行解析,结果表明,其主要来源及贡献率分别为机动车源(27.1%)、二次硫酸盐和硝酸盐(26.8%)、工厂排放(26.4%)和生物质燃烧(19.6%)。  相似文献   

16.
大气气溶胶无机组成的FTIR测定及与离子色谱分析的比较   总被引:4,自引:0,他引:4  
梁咏梅  王美蓉 《环境化学》1997,16(5):456-462
利用傅立叶变换红外光谱仪,固体制样方式,对北京市中关村地区的气溶胶样品中的无机组成进行了分析,并对气溶胶样品中的SO4^2-,NH4^+和NO3^-进行了定量测定,为检验FTIR测定法的可靠性,将FTIR法与离子色谱的测定结果进行了对照分析,结果表明,SO4^2-和NH4^的FTIR测定结果与离子色谱有较好的相关性。  相似文献   

17.
18.

Aim and Scope

This study was aimed at representing current aerosol trends measured at the GAW global station and their relevance for the present fine dust discussion and a possible impact on climate.

Results and Discussion

1) The intensive GAW measuring program at Hohenpeissenberg covers numerous parameters for the characterization of the physical, optical and chemical characteristics of the atmospheric aerosol. The time series of the number concentration of ultra fine particles with diameters of about 0.004 to 3 μm shows an increase of about 50% since 1995. 2) The introduction of soot particle filters would lower the dust mass only slightly since soot particles from diesel cars only about 8–10% contribute to the dust mass, but about 90% to the number concentration of particles. 3) The single scattering albedo (SSA) is a key parameter determining whether the existing aerosol mixture causes a cooling (negative radiative forcing) or a warming (positive radiative forcing) in the atmosphere. At Hohenpeißenberg the SSA changed from 0.85 to 0.91 in the time period 1999 to 2005, i.e. the regional aerosol as a whole is dominated by scattering rather than absorbing particles.

Conclusion and Perspective

From current aerosol trends at the GAW global station Hohenpeißenberg it was possible to analyze their relevance for air pollution control and possible influences on climate. Dust mass is not a suitable parameter for accessing the contribution of diesel engined vehicles. Measuring the number concentration of particles much more reflects the influence of diesel engined vehicles and also shows, as expected, an upward trend due to a strong increase of the fraction of diesel vehicles in comparison to the total number of cars. Aerosol particles scatter and absorb solar radiation and thus cause a cooling or warming in the atmosphere. Calculated values of the single scattering albedo at Hohenpeissenberg show, that in the initial years the aerosol did not diminish the temperature rise, but rather caused it to increase. Only a data comparison from a global network like GAW can demonstrate, if the results are even representative for the large scale situation.  相似文献   

19.
Biological aerosol particles are recently gaining increased attention, but global estimates of their emissions are unclear. Traditional organic tracers for biological particles have not been able to capture the diversity of biological sources such as residential wood burning. Here, we have analyzed protein content in air particulate matter over a year in a suburban area near Shibuya, in order to identify contributions from biological sources. Aerosols were separated into five size fractions using a high-volume cascade impactor. Amino acid profiles were obtained from acid hydrolysates by high-performance liquid chromatography and were subsequently used in a receptor model for source apportionment. Results show that protein content ranged from 0.5 to 2 % throughout the year in all size fractions. We observed contributions from seasonally variable emission sources such as pollen and fallen leaves in coarse particles, larger than 7 µm, at elevated concentrations during spring and winter. We also found contributions from pollen and fallen leaves in the smallest size fraction, lower than 1.1 µm, after spring. This finding indicates that sources are broken up to smaller particles in the urban environment. Overall, our findings demonstrate that protein content can be used as marker for biological aerosol particles, and that protein amino acid composition can distinguish multiple sources.  相似文献   

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