电子显微镜分析北京雨雪中不可溶成分

1994～1995年的冬季和夏季,在北京大学共观测了11次不同类型的雨、雪过程,对每次降水过程进行连续取样和过滤,用电子显微镜分析全部28个降水过滤样品,测定不可溶成分中15种元素(Si、Fe、Al、K、Ca、Cu、Ti、Mg、Na、P、S、Cl、Ni、Mn、Cr)的重量百分比分布.通过平均值计算、聚类法分析和元素间的相关分析,讨论了降水中不可溶成分的物质组成和来源.     

大气气溶胶虚折射指数及其与元素的相关性

在西安、南京采集111个气溶胶样品，测定了虚折射率ni和分析了粒子中Si、Al、Ca、Fe、K、Mg、Mn、Na、Ti、S、P、Pb和Zn的含量。统计分析表明，ni与S和Pb的相关系数r最高，分别为0.36和0.30，统计检验也表明，这一相关性是显著的。其它11种元素与ni的相关性较差，且并不显著。西安气溶胶S含量明显高于南京，它与ni之间的相关系数高出南京近一倍。这些结果表明，除碳C之外，气溶胶中的S和Pb及其化合物对辐射的吸收不能忽视。     

北京冬春季节大气气溶胶化学成份的研究

1980年3月6日至20日,利用美国佛罗里达州立大学自制的条式连续采样仪,在北京北郊大气物理所气象塔观测场取得连续两周的大气气溶胶样品。用PIXE方法分析,得到了该样品中 Ca、Fe、Al、Si、K、Cl、S、Ti、Mn、Zn、Sr、pb等微量元素的相对浓度。 本文分析了北京冬春季节大气气溶胶化学元素的浓度分布特征以及浓度变化与气象条件的关系。并与其他地区的观测结果作了比较。     

北京北郊冬季低空大气气溶胶分析

文章分析了2001年1月10～16日和2月20日～3月2日两时段北京北郊中国科学院大气物理研究所325 m高的气象塔上距地面320、100和8 m 3个高度所采得的气溶胶样品的物理化学特征.计算了气溶胶的TSP浓度、化学组分及其分布和粒度谱.探讨了气象条件对气溶胶浓度及其来源和分布的影响.初步发现在所测的高度范围内,气溶胶TSP的浓度随高度的增高而下降,70%以上浓度分布在细粒组(d<2.1 μm).气溶胶中浓度最高的前20个元素是S、Fe、Ca、Al、K、Na、Mg、Zn、P、Ti、Pb、Ba、Mn、Cu、V、As、Cr、 Rb、Sb和Br.挥发性元素主要分布在细粒组,元素浓度随高度增加而减少.气溶胶的离子浓度也有相同的分布特征.风速变小、层结呈现稳定,尤其逆温以及大气湿度升高均为气溶胶浓度升高的因素.人为排放源是大气气溶胶的主要贡献者.导致北京严重空气污染的气溶胶源地以北京当地及其周边邻近地区的污染源为主.     

云南丽江大气气溶胶的化学成分谱分析

对云南省丽江玉龙雪山地区大气气溶胶化学元素成分进行了观测和分析.结果表明,丽江玉龙雪山大气气溶胶以Mg、Al、Ca、Si、K和Fe等地壳元素为主,占总元素浓度的82%.丽江地区气溶胶Pb、Se、Br元素浓度均高于珠峰浓度值.丽江气溶胶S、As、Se、Br和Pb等与人类活动有关的气溶胶元素的富集因子很高.这表明丽江地区人类活动影响不容忽略.     

Size Distributions and Elemental Compositions of Particulate Matter on Clear, Hazy and Foggy days in Beijing, China

Total suspended particulates(TSP)samples were collected using low pressure impactors(Andersen Series 20-800,USA)on typical clear,hazy and foggy days in Beijing in order to investigate the characteristics of size distributions and elemental compositions of particulate matter(PM)in different weather conditions. The concentrations of sixteen elements,including Na,Mg,Al,K,Ca,Mn,Fe,Ni,Cu,Zn,As,Se,Cd,Ba,Tl and Pb were detected using inductively coupled plasma mass spectrometry(ICP-MS).The results showed that Ca,Al,Fe,Mg and Ba on foggy days were 2.0-2.6 times higher than on clear days,and 2.3-2.9 times higher than on hazy days.Concentrations of Cu,Zn,As,Se and Pb on foggy days were 163.5,1186.7,65.9,32.0 and 708.2 ng m-3,respectively,in fine particles,and 68.1,289.5,19.8,1.6 and 103.8 ng m-3,respectively,in coarse particles.This was 1.0-8.4 times higher and 1.4-7.4 times higher than on clear and hazy days,respectively.It is then shown that Mg,Al,Fe,Ca and Ba were mainly associated with coarse particles,peaking at 4.7-5.8μm;that Cd,Se,Zn,As,Tl and Pb were most dominant in fine particles,peaking at 0.43-1.1μm;and that Na,K,Ni,Cu and Mn had a multi-mode distribution,with peaks at 0.43-1.1μm and 4.7-5.8μm.The enrichment factors indicated that coal combustion along with vehicle and industry emissions may be the main sources of pollution elements.     

天津大气气溶胶化学组分的粒径分布和垂直分布

2006年8月在天津气象铁塔的10、120、220 m 3个不同高度.利用Andersen分级采样器同步进行大气气溶胶采样,样品用离子色谱和电感耦合等离子体质谱仪进行分析.结果表明,K元素主要集中在细粒子,Mg、Ca、Al、Fe元素主要集中在粗粒子,Na元素则具有双峰结构;总离子浓度随着高度的升高有增加的趋势,SO42-、N3-、NH4+、Ca2+是最主要的水溶性尤机离子;二次源是水溶性离子重要的贡献源.NO3-、SO42-、NH4+随着高度升高,浓度有向小粒径集中的趋势;各层气溶胶阴阳离子平衡值小于1,表明气溶胶偏碱性,与天津地处北方,土壤偏碱性,且非采暖期地面扬尘是主要的气溶胶来源有关;各层NO3-/SO42-平均值为0.48,表明非采暖期固定排放源(燃煤)仍然是天津大气细粒子中水溶性离子的主要来源.     

华北典型农业区PM2.5组分分析与来源解析

华北大气污染区域化正在对农业生态区域产生显著影响,为了了解华北农业地区大气细颗粒物PM2.5的季节分布特征,2017年7月、9月、12月以及2018年4月在中国科学院禹城农业生态综合实验站进行分季节PM2.5样品采集,并测定分析了样品中31种化学成分.结果表明,碳质气溶胶总体的浓度水平为13.11±8.37μg m-3,有机碳(OC)冬春季节浓度较高,元素碳(EC)浓度在秋冬季节较高.同时OC/EC的比值在秋季明显偏低,表明在秋季二次碳质气溶胶对PM2.5贡献较小.水溶性离子浓度总体在冬季最高.NO3-/SO2-4比值在夏季明显偏低为0.69,华北地区夏季固定点源对大气污染的贡献相对较高.PM2.5中金属元素以Na、Mg、Al、Ca、K、Fe等地壳元素为主,具有致癌风险的Co、Cr、Ni、Pb、As等金属元素年均浓度为0.32±0.24 ng m-3、5.40±5.42 ng m-3、10.23±7.46 ng m-3、42.23±27.75 ng m-3、5.66±3.79 ng m-3.受体模型(PMF)计算结果表明,PM2.5的主要来源为二次污染源、生物质燃烧源、燃煤燃油源、柴油车尾气和土壤源,贡献率分别达37.1％、18.2％、14.2％、9.4％和7.9％,表明农业区细颗粒物污染受到华北工业、农业与自然排放的多重影响.     

南京市大气细颗粒物化学成分分析

为了解南京大气细粒子的污染水平和污染特征,在南京市中心鼓楼和北郊南京信息工程大学校内进行了连续1a、每季度5d的大气气溶胶同步采样。用称重法、离子色谱法和电感耦合等离子质谱法分别测得细颗粒物的质量浓度、水溶性离子和元素组成。结果表明,南京地区PM2.1污染比较严重,水溶性离子是细粒子的重要组分,所测6种离子质量浓度总和分别占市区和北郊PM2.1的46.99％、42.32％。PM2.1中的各离子最高浓度都出现在冬季。NH^＋4与SO^2-4的相关性好,可能主要以（NH4）2SO4形式存在。温度对SOR和NOR的影响显著,温度升高时SOR值增大而NOR显著减小。通过计算NO^-3与SO^2-4的质量比发现,南京市SO2和NOx主要来自于固定源（如煤的燃烧）。分析细颗粒物中元素含量和富集因子结果表明,Pb、As、Zn、Hg、Cu、Cr、Ni元素的人为污染较明显,且北郊的污染重于市区。比较PM2.1和PM3.3中的离子成分发现,SO^2-4、NH^＋4在PM2.1中占据绝对优势,F^-、Cl^-、NO^-2、NO^-3等不在细粒子中占明显优势。从元素组成来看,Pb、Zn在PM2.1细粒子中含量显著,而Ca、Mg、Na等在粗粒子中富集。     

北京一月大气气溶胶的化学成分及其谱分布

1983年1月分别在市中心生活区和市郊气象塔处进行了为期10天的气溶胶采样,获得26组分级采样样品,样品用PIXE方法进行了分析,得到了20种元素的浓度及其谱分布.发现大多数元素的谱分布都是双模的,但细粒和粗粒气溶胶分量的相对强度各不相同.Ca,Al和Ti等元素以粗粒态为主;Zn,As和Pb等以细粒态为主;Cl,K,S,Si等二种分量相当.其中S和Si的谱分布与过去文献中的报道有很大区别,表明它们来源的复杂性.粗粒态气溶胶中除个别元素外,城区浓度大约是市郊浓度的1.4倍,而细粒气溶胶各元素浓度城区与郊区差     

Elemental composition of PM2.5 and PM10 at Mount Gongga in China during 2006

In order to investigate the chemical characteristics of atmospheric aerosols in a regional background site, PM_2.5 and PM₁₀ were collected at Mount Gongga Station once a week in 2006. The concentrations of fifteen elements including Na, Mg, Al, K, Ca, V, Fe, Ni, Cu, Zn, As, Ag, Ba, Tl, and Pb were detected by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The results showed that Na, Mg, Al, K, Ca, Fe were the major components of elements detected in PM_2.5 and PM₁₀, occupied 89.5% and 91.3% of all the elements. Crustal enrichment factor (EF) calculation indicated that several anthropogenic heavy metals (Ni, Cu, Zn, As, Ag, Tl, Pb) were transported long distances atmospherically. The concentrations of all elements (except Na) measured in PM_2.5 and PM₁₀ in spring and winter were higher than those in summer and autumn. The backward air mass trajectory analysis suggests that northeast India may be the source region of those pollutants.     

Continuous Measurement of Number Concentrations and Elemental Composition of Aerosol Particles for a Dust Storm Event in Beijing

A continuous measurement of number size distributions and chemical composition of aerosol particles was conducted in Beijing in a dust storm event during 21-26 March 2001. The number concentration of coarse particles （ 〉2μm） increased more significantly than fine particles （ 〈2μm） during the dust storm due to dust weather, while the anthropogenic aerosols collected during the non-dust-storm period tended to be associated with fine particles. Elemental compositions were analyzed by using proton-induced X-ray emission （PIXE）. The results show that 20 elements in the dust storm were much higher than in the non-dust-storm period. The calculated soil dust concentration during the dust storm was, on average, 251.8μg m^-3, while it was only 52.1μg m^-3 on non-dust-storm days. The enrichment factors for Mg, A1, P, K, Ca, Ti, Mn, Fe, C1, Cu, Pb, and Zn show small variations between the dust storm and the non-dust-storm period, while those for Ca, Ni and Cr in the dust storm were much lower than those in the non-dust-storm period due to significant local emission sources. A high concentration and enrichment factor for S were observed during the dust storm, which implies that the dust particles were contaminated by aerosol particles from anthropogenic emissions during the long-range transport. A statistical analysis shows that the elemental composition of particles collected during the dust storm in Beijing were better correlated with those of desert soil colleted from desert regions in Inner Mongolia. Air mass back-trajectory analysis further confirmed that this dust storm event could be identified as streaks of dust plumes originating from Inner Mongolia.     

Mass closure of total suspended particles over the coal burning power production area of western Macedonia, Greece

Ambient suspended particles (TSP) were collected from January to June 2001 at seven sampling sites in western Macedonia, Greece, where four thermal power stations are located. TSP samples were chemically characterized for minerals (Fe, Al, Mg, Ca, K, Ti and Si), trace elements (P, Cd, Cr, Cu, Mn, Pb, V, Zn, Te, Co, Ni, Se, Sr, As, and Sb), water-soluble ions , carbonaceous compounds (OC/EC) and polycyclic aromatic hydrocarbons (PAHs). These classes of compounds were consequently compared with PM mass concentrations of TSP in order to perform mass closure. PM chemical compositions exhibited differences at the seven sites. Minerals were found to be more abundant at four sites, electrolytes dominated the composition at two of the sites while carbonaceous material was most abundant only at one site. The fraction unaccounted for ranged between 22 and 34%. Spatial variations of atmospheric concentrations showed significantly higher levels of minerals, some trace metals and TC at the site that was closest to the power plants. At the same site ions exhibited high correlations with minerals and the majority of trace elements.     

Biological and Temporal Variations of Trace Element Concentrations in the Moss Species Scleropodium purum (Hedw.) Limpr.

Over a period of one year, the moss Scleropodium purum was sampled every two weeks in a French rural area to determine the levels of Li, Na, Al, Si, P, Ca, V, Mn, Fe, Zn, Ba, Hg, and Pb. The element distribution in the moss shoot was studied throughout the year. An apical bioconcentration was discovered for Na, P, Ca, Mn, and Zn, whereas higher levels were found in the basal fraction for Li, Al, Si, V, Fe, Ba, Hg, and Pb. A significant variation of element concentrations was observed during the sampling period. In the apical part Li, Al, Si, V, Fe, Ba, and Hg show maximum levels in the summer and minimum in the autumn. The same pattern was found with Ca and Mn in the whole plant, whereas Na showed opposite fluctuations.     

武汉市源成分谱特征研究

通过采集武汉市土壤风沙尘、建筑水泥尘、城市扬尘、餐饮源、生物质燃烧源、工业煤烟尘和电厂煤烟尘等7类源样品,并分析其碳组分、水溶性离子组分和无机元素组分,建立PM₁₀和PM_2.5源成分谱.研究表明,地壳元素Si、Ca、Al以及Fe等是土壤风沙尘的主要特征组分,其中Si是含量最高的成分,也是土壤风沙尘的标识组分.无组织建筑水泥尘中Si和Ca元素含量较高,将Ca元素作为无组织建筑水泥尘区别其他源类的重要元素,而有组织建筑水泥尘中OC、SO₄^2-含量比无组织建筑水泥尘高.城市扬尘中Ca的含量相对较高,表明城市扬尘受到建筑水泥尘影响较多.生物质燃烧源成分谱中OC的含量远高于成分谱中其他组分,另外Cl^-和K的平均含量也较高,K一般为生物质源的特征元素.     

Elemental particle size distributions. Measured and estimated dry deposition in Sfax region (Tunisia)

Mass size distribution of the crustal elements (Al, Ca, Fe, Mg, Si, Ti), anthropogenic elements (Zn, Mn, Cr, Cu, K, P, Pb) and sea elements (Na, Cl) were obtained from measurements carried out with an inertial cascade impactor in Sfax. A fitting procedure by data inversion was applied to those data. This procedure yields accurate size distributions of aerosols in the diameter range 0.1–25 μm in two different sites. In a coastal industrial site, the mass distribution of the aerosol showed a bimodal structure; and in urban area, the lower particle mode cannot be observed. The elemental dry deposition flux was calculated as a function of particle size. The element flux size distribution increased rapidly with particle size. The modelling results indicate that the majority of the crustal and anthropogenic elements flux (>90%) was due to particles larger than 3 μm in diameter.     

塔里木盆地不同地域大气降尘TSP变化特征分析

为了解塔里木盆地不同地域大气降尘及TSP的污染特征和季节变化规律,在塔里木盆地布设了铁干里克、塔中、民丰、喀什4个采样站点,于2007-2010年期间利用集尘缸和大流量采样器分别对上述4个地区的大气降尘及TSP进行连续采样。通过对样品和数据的分析处理,揭示了塔里木盆地不同地域大气降尘及TSP基本特征及影响因素：（1）2007-2010年塔中大气降尘量和TSP浓度均为4个站点中最高,其次为民丰和喀什,铁干里克最少。区域气候差异是造成塔里木盆地降尘和TSP浓度空间分布差异的主要原因。（2）5-8月是塔中地区沙尘天气高发时节,7月沙尘暴天气处于峰值。3-8月是民丰、喀什和铁干里克大气降尘主要分布月份。春夏季节的塔里木盆地降尘污染明显高于秋冬季节。（3）每年3-9月都是4个站点TSP主要分布阶段,最高值出现月份略有差异。塔里木盆地周边TSP浓度季节变化大体一致,春夏季大于秋冬季,不同的地区季节分布略有差异。（4）春夏季沙尘天气是造成大气降尘和TSP质量浓度较高的主要因素。     

Influence of traffic emissions on the composition of atmospheric particles of different sizes – Part 1: concentrations and elemental characterization

Epidemiological studies initially considered the impact of total solid particles on human health, but according to the acquired knowledge about the worse effect of smaller particles, those studies turned to consider the impact of PM₁₀. However, for the last decade PM_2.5 began to be more important, once as they are smaller they can penetrate deeper in the lungs, being possible their trapping in alveoli and worse effects on human health. Therefore, more information on PM_2.5 should be provided namely concerning the levels and elemental composition. Considering the relevance of traffic on the emission of particles of small sizes, this work included the detailed characterization of PM₁₀ and PM_2.5, sampled at two sites directly influenced by traffic, as well as at two reference sites, aiming a further evaluation of the influence of PM₁₀ and PM_2.5 on public health. The specific objectives were to study the influence of traffic emission on PM₁₀ and PM_2.5 characteristics, considering concentration, size distribution and elemental composition. PM₁₀ and PM_2.5 samples were collected using low-volume samplers; the element analyses were performed by particle induced X-ray emission (PIXE). At the sites influenced by traffic emissions PM₁₀ and PM_2.5 concentrations were 7–9 and 6–7 times higher than at the background sites. The presence of 17 elements (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn and Pb) was determined in both PM fractions; particle metal contents were 3–44 and 3–27 times higher for PM₁₀ and PM_2.5, respectively, than at the backgrounds sites. The elements originated mostly from anthropogenic activities (S, K, V, Mn, Ni, Zn and Pb) were predominantly present in PM_2.5, while the elements mostly originated from crust (Mg, Al, Si and Ca) predominantly occurred in PM_2.5–10. The results also showed that in coastal areas sea salt spray is an important source of particles, influencing PM concentration and distributions (PM₁₀ increased by 46%, PM_2.5/PM₁₀ decreased by 26%), as well as PM compositions (Cl in PM₁₀ was 11 times higher).