西安市春季大气颗粒物PM_(2.5)与PM_(10)的特征

2010年4月在西安市区4个点使用低流量采样器同步连续采集2周(24 h/d)细颗粒物PM2.5和可吸入颗粒物PM10样品,分别利用热光碳分析仪、离子色谱和X射线荧光光谱仪分析其含碳组分(有机碳和元素碳)、水溶性无机离子(NH4+、Na+、K+、Ca2+、Mg2+、F-、Cl-、SO42-、NO3-)和元素Ca、Fe等浓度。结果表明,沙尘暴期间,PM10的质量浓度是PM2.5的3倍,PM2.5和PM10中有机碳浓度大于正常天气的,SO42--NO3--NH4+浓度急剧减小,明显小于正常天气,这与干燥沙尘暴的稀释作用有关;后向轨迹、气溶胶指数和Ca与Fe元素质量浓度比验证了沙尘暴颗粒来源西部戈壁沙尘和黄土高原;阴阳离子平衡计算显示沙尘事件颗粒物呈碱性,阴阳离子差异估算的CO32-含量与Ca2+具有强相关性,表明沙尘暴颗粒以CaCO3为主。     

室内外细粒子PM_(2.5)和总悬浮颗粒物污染水平的对比研究

为了解室内外空气颗粒物PM2.5和总悬浮颗粒物(TSP)的污染状况,自2008年3月24日～4月3日在西安交通大学学生办公室、教师办公室、化学实验室和室外同时采集PM2.5和TSP样品,对其质量浓度及无机水溶性离子组分(Na+、NH4+、K+、Mg2+、Ca2+、Cl-、NO3-和SO42-)进行了分析。结果表明,室内外PM2.5和TSP浓度都远远高于美国空气质量标准规定的35μg/m3。室内外颗粒物浓度具有相同的变化趋势,且室内总体上低于室外。室内PM2.5在TSP中所占比例在65%～85%,室外在40%左右。室内外TSP和PM2.5中二次污染离子SO42-、NO3-和NH4+占总离子质量的50%以上,主要富集在细颗粒中。NH4+、K+和Cl-在总离子中的比例均为室内大于室外,PM2.5中大于TSP。Ca2+、Mg2+主要富集在粗颗粒上,室外含量远远高于室内。     

武汉秋季灰霾和非灰霾天气细颗粒物PM_(2.5)中水溶性离子的特征

分析了武汉地区武大和天虹2个采样点秋季灰霾和非灰霾天气细颗粒物PM2.5中的9种水溶性离子(F-、Cl-、NO3-、SO42-、Na+、NH4+、K+、Mg2+、Ca2+)浓度。结果表明,NO3-、SO42-和NH4+是武汉秋季PM2.5中最重要的3种水溶性离子,且PM2.5中各水溶性离子之间组成比例相对稳定;灰霾期PM2.5中水溶性离子比例的增大是武汉秋季灰霾污染的重要特征,它们可能来源于生物质燃烧、土壤扬尘、化石燃料燃烧、汽车尾气排放等过程,其中天虹站点的大气二次污染比武大站点的严重,固定源对武汉2个站点秋季灰霾期大气中NOx与SO2相对贡献均比非灰霾期的大,移动源对天虹站点秋季大气中NOx与SO2的相对贡献则比武大站点的大。     

陕西省榆林市冬季PM_(10)和PM_(2.5)的污染特征

为了探讨陕西省榆林市冬季大气颗粒物的污染特征,2013年11月对榆林市3个采样点进行可吸入颗粒物(PM10)和细颗粒物(PM2.5)同步观测,利用离子色谱法和热光分析法测定PM10和PM2.5中无机水溶性离子和碳组分的浓度。结果表明:3个采样点PM10和PM2.5日均质量浓度分别为162、74μg/m3,颗粒物浓度由大到小的采样点为环保旧站、实验中学和环保大厦;PM10中有机碳和元素碳的质量浓度空间分布与颗粒物的相同;PM2.5中有碳组分在环保旧站和实验中学的浓度接近,都大于环保大厦的;无机离子中SO42-和Ca2+浓度最大;PM10与PM2.5整体偏碱性,亏损的阴离子主要是CO32-;扬尘在PM10中的比例远远大于其他组分;PM2.5中碳组分含量较大,其次是土壤尘、硫酸盐、氯化物和硝酸盐等;治理PM10和PM2.5污染应以加强扬尘控制和减少燃煤污染物排放为主。     

秦兵马俑博物馆陶器库房冬季室内空气质量初步研究

于2008年1月30日～3月3日,在秦始皇兵马俑博物馆陶器库开展了室内大气环境调查,同步采集了大气悬浮颗粒PM2.5和NH3样品,获得了PM2.5颗粒中的离子组成,并实时监测了SO2、NOx的浓度变化。结果表明,陶器库中PM2.5平均质量浓度为76.1μg/m3,室外PM2.5平均质量浓度为153.9μg/m3,约为室内浓度的2倍。室内PM2.5中水溶性离子主要由SO42-、NO3-和NH4+组成,平均质量浓度分别为17.5、5.2、5.5μg/m3,它们分别占PM2.5质量浓度的19.7%、5.2%、5.8%。库内NH3平均浓度为4.8μg/m3,室外NH3平均浓度6.6μg/m3,约为室内的1.4倍。室内NO、NO2、NOx浓度日平均分别为4.8×10-9、3.2×10-9、8.0×10-9,SO2浓度日平均为0.9×10-9。研究表明,库内人为活动量对质量浓度、离子浓度和污染气体均有一定影响,库房相对于室外对阻挡颗粒物减少外界影响方面对文物有一定的保护作用,但在阻隔空气污染物和恒温恒湿方面的作用还有待加强。     

道路旁大气悬浮微粒的理化特性及污染源解析(英文)

旨在探讨道路旁悬浮微粒之理化成分,并解析其可能的污染来源。悬浮微粒采样作业于2003年5月～2004年1月期间进行,悬浮微粒样本采集时间包括春、夏、秋、冬四季的假日与非假日,所采集的悬浮微粒样本经化学成分分析可得水溶性离子成分与金属元素成分,并透过化学质量平衡受体模式及逆轨迹模式进行污染源解析。测量结果显示,假日的大气悬浮微粒PM10浓度高于非假日,而假日与非假日的总悬浮颗粒则无明显变化。此外,道路旁悬浮微粒PM10主要受非交通源的长程传输与当地的交通源所影响,而总悬浮颗粒则主要源自于附近道路的车行及逸散扬尘。另就悬浮微粒化学成分而言,金属元素成分以Ca、Fe、Al最多,水溶性离子成分则主要为SO42-、NO3-、NH4+等二次污染物。受体模式及逆轨迹模式分析结果得知,污染来源主要为交通污染及道路扬尘,然而,亦有相当部分的污染来自上风处的非交通源。     

道路旁大气悬浮微粒之理化特性及污染源解析

旨在探讨道路旁悬浮微粒之理化成分,并解析其可能的污染来源.悬浮微粒采样作业于2003年5月～2004年1月期间进行,悬浮微粒样本采集时间包括春、夏、秋、冬四季的假日与非假日,所采集的悬浮微粒样本经化学成分分析可得水溶性离子成分与金属元素成分,并透过化学质量平衡受体模式及逆轨迹模式进行污染源解析.测量结果显示,假日的大气悬浮微粒PM10浓度高于非假日,而假日与非假目的总悬浮颗粒则无明显变化.此外,道路旁悬浮微粒PM10主要受非交通源的长程传输与当地的交通源所影响,而总悬浮颗粒则主要源自于附近道路的车行及逸散扬尘.另就悬浮微粒化学成分而言,金属元素成分以Ca、Fe、Al最多,水溶性离子成分则主要为SO42-、NO3-、NH4+等二次污染物.受体模式及逆轨迹模式分析结果得知,污染来源主要为交通污染及道路扬尘,然而,亦有相当部分的污染来自上风处的非交通源.     

杭州市道路空气细颗粒物PM_(2.5)元素组成特征

采用微波消解-电感耦合等离子体质谱法及电感耦合等离子体发射光谱法测定2010—2011年杭州市3条典型道路两侧代表秋、冬、春、夏4个季节的细颗粒物PM2.5中22种元素的质量浓度,分析其时空分布规律、特征及来源。结果表明:道路两侧PM2.5中元素含量与道路类型关系不大,呈现夏季小、其余季节大的态势,主要污染元素为Zn、Pb、Cu、Ni;受机动车排放的影响,道路两侧PM2.5呈无机元素含量小、有机元素含量大的特征;Fe、K、Mg、Na、P、Si等土壤元素主要来自机动车行驶引起的道路扬尘;机动车污染特征元素Pb、Zn、Cu、Cd来自相同人为源;机动车污染是道路两侧土壤和灰尘中重金属的主要来源;随着机动车保有量的持续增长,道路两侧PM2.5中Pb仍维持着较高的富集水平。     

北京城区和远郊区大气细颗粒PM_(2.5)元素特征对比分析

为了对比大气悬浮颗粒PM2.5及其所含元素在北京城区与远郊区的特征,在2007年不同季节和2008年北京奥运会期间进行了PM2.5的采样分析。结果表明:城区PM2.5和元素的浓度均高于郊区,元素浓度在城区与郊区具有不同的季节变化特征,春、冬季地壳元素浓度在城区与郊区都有所增加,在城区S元素和其它污染元素在秋、冬季最高,而郊区S元素浓度在夏季最高。污染元素的富集程度夏秋季高于春冬季,郊区高于城区,城、郊两地PM2.5中元素来源相似。雾霾天PM2.5及元素浓度在城区增加明显,奥运期间污染元素的质量分数较奥运前明显降低。     

杭州主城区悬浮细颗粒PM_(2.5)浓度变化及其组分分析

利用杭州市区2006—2008年大气悬浮颗粒PM2.5和PM2.5-10的监测资料,研究它们的物化特征。结果表明:杭州主城区PM2.5和PM2.5-103年的平均浓度分别为0.073、0.037mg·m-3,ρ(PM2.5)/ρ(PM2.5-10)的比值为1.86。PM2.5浓度存在双峰型日变化,以9:00和18:00为峰值,日变化幅度较大,并呈现冬高、夏低的季节变化。PM2.5化学组分分析表明:PM2.5中含量最多的是有机碳,占24.4%,其次是SO42-,不同组分呈现不同的季节变化。     

Concentrations of ambient air particulates (TSP, PM2.5 and PM2.5-10) and ionic species at offshore areas near Taiwan Strait

The concentrations of total suspended particulate (TSP), fine particles PM(2.5) (with aerodynamic diameter <2.5 microm), coarse particles PM(2.5-10) (with aerodynamic diameter 2.5-10 microm,), and water-soluble inorganic ions were studied at two offshore sampling sites, Taichung Harbor (TH) and Wuci Traffic (WT), near Taiwan Strait in central Taiwan during March 2004 to January 2005. Statistical analyses were also carried out to estimate the possible sources of particulate pollution. Experimental results showed that the average mass concentrations of TSP, PM(2.5) and PM(2.5-10) at TH and WT sampling sites were 154.54 +/- 31.45 and 113.59 +/- 31.94 microg m(-3), 54.03 +/- 16.92 and 42.76 +/- 12.52 microg m(-3), and 30.31+/- 9.79 and 24.16 +/- 7.27 microg m(-3), respectively. The dominant inorganic ions at two sampling sites were SO(4)(2-), NO(3)(-), and NH(4)(+) for TSP and PM(2.5), but that were Ca(2+), Cl(-), and Na(+) for PM(2.5-10). The concentrations of most particulates and inorganic ions were higher in winter at both two sampling sites, and were higher at TH than WT sampling site in each season. From statistical analysis, air-slake of crust surface, sea-salt aerosols, agriculture activities, coal combustion, and mobile vehicles were the possible emission sources of particulate pollution at TH and WT sampling sites.     

杭州市大气悬浮颗粒PM_(2.5)污染状况及化学组成特征分析

为了解杭州市大气悬浮颗粒物PM2.5污染状况及化学组成特征,2006年在杭州市内布设2个监测点位,按季节进行采样,并对悬浮颗粒物PM2.5中20种元素进行定量研究。结果表明:杭州市区大气中悬浮颗粒物PM2.5的年均质量浓度值为77.5μg/m3,其中S、Si、Ca、K等元素年平均质量浓度大于1.0μg/m3。元素Si、Al、Fe、Mg、V、K、Na、Ti、Mn、Ca、P、Cr、Ni主要来源于地壳,而元素Cl、Cu、Zn、Pb、As、Br、S、Se等主要来源于人为排放源。     

Statistical analysis of atmospheric trace metals and particulate fractions in Islamabad, Pakistan

Airborne suspended particulate matter was collected on glass fibre filters in urban atmosphere of Islamabad, Pakistan, using high volume sampler. The particulate samples were analysed for 10 selected metals (Fe, Na, Zn, K, Pb, Mn, Cr, Ni, Co and Cd) by FAAS method. Maximum mean contribution was noted for Fe (1.761microg/m(3)), followed by Na (1.661microg/m(3)), Zn (1.021microg/m(3)), K (0.488microg/m(3)) and Pb (0.128microg/m(3)). The particle size determination on vol.% basis for nine fractions (PM(<1.0), PM(1.0-2.5), PM(2.5-5), PM(5-10), PM(10-15), PM(15-25), PM(25-50), PM(50-100) and PM(>100)) was carried out using Mastersizer. PM(5.0-10) were found to be most abundant in the local atmosphere followed by PM(2.5-5.0) and PM(15-25) while coarse/giant particles (PM(50-100) and PM(>100)) showed lower contribution. The trace metals were found to be mainly associated with smaller particulate fractions up to PM(10-15). Among the climatic parameters temperature has significant relationship with fine particles and airborne metal levels while relative humidity showed negative correlation. The source identification was carried out by principal component analysis and cluster analysis. Five metal sources were identified: industrial, vehicular emissions, metallurgical operations, garbage incineration and soil derived dust. The metal levels were also compared with those reported for other rural and urban parts around the world.     

A review of atmospheric fine particulate matter and its associated trace metal pollutants in Asian countries during the period 1995-2005

Many studies have monitored atmospheric particulates and gaseous phases of PM(2.5) in Asia over the past 10 years. This work also compared and discussed different sample collection, pretreatment and analytical methods in Asia countries in past decade. The results indicated that the main PM(2.5) sources are traffic exhausts. PM(2.5) concentrations are also ranked highest in the areas of traffic, followed by the urban sites, and lowest in rural sites in Asian countries. This work elucidates the sources, analytical tools, and the average concentrations for PM(2.5) and related metallic elements during 1995-2005. The results indicated that the average highest concentrations order of metallic elements for PM(2.5) were Fe>Mg>Zn, and the average concentrations of lowest metallic elements was Pb>Cu>Mn>Cr>Cd. The results also indicated that the concentration of metallic element Cu increased as the averaged concentrations of metallic element Zn and Mn increased during the past 10 years in Asian countries.     

Estimation of selected heavy metals and arsenic in PM10 aerosols in the ambient air of the Greater Athens Area, Greece

Aerosol samples of PM(10) were collected during summer and winter 2003 at two different sites in the Messogia Basin northeast of Athens, to demonstrate the variations of heavy metals in PM(10) and examine their relationship with both gaseous pollutants and meteorological parameters. Estimated heavy metals during the experimental campaign were mercury (Hg), cadmium (Cd), lead (Pb), nickel (Ni) and arsenic (As). The average heavy metal concentrations for the first site (Spata) constituted 0.66-14.7ng/m(3) for the summer period and 0.14-19.5ng/m(3) for the winter period. At the second site (Koropi), the corresponding values varied between 0.89 and 13.3ng/m(3) and 0.16 and 24.7ng/m(3), respectively. PM(10) Hg, PM(10) Cd and PM(10) Ni contents showed regular daily variations, with higher mass percentages during the summer, indicating differences in local PM(10) sources for each season. On the contrary, PM(10) Pb presented higher mass percentages during the winter. Examination of the relationship between heavy metals and meteorological parameters indicated a higher correlation with temperature and relative humidity, especially for Pb. In addition, most of the heavy metals (apart from Hg) presented an expected correlation with nitrate oxides (NO(x)), PM(10) and ozone (O(3)). Higher correlations with both meteorological parameters and gaseous pollutants were observed during the winter experimental campaign. Maximum heavy metal concentrations at both sites were observed during days with NE or NNE prevailing winds during the summer campaign, while the winter period was characterized with maximums during days with W or WNW prevailing winds.     

Reliability evaluation of nano-bi/silver paste sensor electrode for detecting trace metals

The reliability of sensor characteristics for a nano-bismuth (Bi)/silver (Ag) paste electrode has been investigated by comparison with Hg/Bi film electrodes in terms of accuracy and precision. Using Ag paste instead of carbon paste as a conducting layer, the sensitivity and detection limit of the sensor electrode were more enhanced due to a lower electrical conductivity of Ag. For the evaluation of detecting ability, the Zn, Cd, and Pb ion concentrations of the prepared standard solutions were experimentally measured on Hg film, Bi film, and nano-Bi electrodes using anodic stripping voltammetry. A nano-Bi electrode can detect Zn, Cd, and Pb ions at 0.1 ppb with higher precision and accuracy compared with Hg film and Bi film electrodes. From the trace analyses of Zn, Cd, and Pb ions in commercial drinking water and river water using a nano-Bi electrode and inductively coupled plasma (ICP) technique, it was concluded that the nano-Bi electrode exhibited excellent sensing characteristics with high reliability, and could detect even traces of Zn, Cd, and Pb ions that were not detected by the ICP method.     

Evaluation of assisting agents for electrodialytic removal of Cd,Pb, Zn,Cu and Cr from MSWI fly ash

Different assisting agents (0.25 M ammonium citrate/1.25% NH(3), 0.25 M Na-citrate, 2.5% NH(3), DI water) have been used for aiding the removal of heavy metals during electrodialytic treatment of municipal solid waste incineration (MSWI) fly ash. In this study, the effectiveness of the different agents was evaluated. The heavy metal speciation in solution was discussed and simulated at the different conditions using the geochemical equilibrium model Visual MINTEQ. The heavy metals examined were Cd, Pb, Zn, Cu and Cr.The 2.5% NH(3) solution was the best assisting agent for removal of Cd, probably due to formation of stable tetraammine complexes; whereas the best Pb removal was obtained with 0.25 M Na-citrate (Pb forms very stable chelates with citrate). The best compromise for removal of all five metals was obtained with the 0.25 M ammonium citrate/1.25% NH(3) solution.     

离子色谱法同时测定福州大气PM2.5中无机阴离子和有机酸的研究

本文利用离子色谱法对福州市2015-2016年大气PM_2.5样品中4种无机阴离子(F^-、Cl^-、NO₃^-、SO₄^2-)和5种水溶性有机物(WSOC)(甲酸、乙酸、乙二酸、丁二酸、戊二酸)进行同步测定,结果表明,无机阴离子曲线相关系数大于0.999,有机酸相关系数大于0.994,检出限范围(0.7-25.7)ng/m³,精密度范围(0.3-7.9)%,回收率范围(84.0-116)%,方法性能满足测试要求。SO₄^2-、NO₃^-、Cl^-为主要的水溶性无机阴离子,3种离子浓度之和占PM2.5质量浓度的32.6%。5种水溶性有机酸WSOC的浓度均值范围为(0.031-0.308)μg/m³,总和占PM2.5质量浓度的1.6%,其中乙二酸的含量相对最高。总体而言,PM2.5中水溶性无机离子和有机酸浓度的季节变化表现为春、冬季高,夏、秋季低的特点。NO₃^-、乙二酸在夏季表现出不同的浓度特征可能与物质的性质和夏季高温强辐射天气有关。乙二酸与SO42-、NH4+、NO3-有较强的线性相关性,初步推断其主要来源为光化学反应而形成的二次污染物。