Distinct potential aerosol masses under different scenarios of transport at a suburban site of Beijing

In order to evaluate the secondary aerosol formation potential at a suburban site of Beijing,in situ perturbation experiments in a potential aerosol mass(PAM) reactor were carried out in the winter of 2014.The variations of secondary aerosol formation as a function of time,OH exposure,and the concentrations of gas phase pollutants and particles were reported in this study.Two periods with distinct secondary aerosol formation potentials,marked as Period Ⅰ and Period Ⅱ,were identified during the observation.In Period Ⅰ,the secondary aerosol formation potential was high,and correlated well to the air pollutants,i.e.,SO_2,NO_2,and CO.The maximal secondary aerosol formation was observed with an aging time equivalent to about 3 days of atmospheric oxidation.In period Ⅱ,the secondary aerosol formation potential was low,with no obvious correlation with the air pollutants.Meanwhile,the aerosol mass decreased,instead of showing a peak,with increasing aging time.Backward trajectory analysis during the two periods confirmed that the air mass in Period Ⅰwas mainly from local sources,while it was attributed mostly to long distance transport in Period Ⅱ.The air lost its reactivity during the long transport and the particles became highly aged,resulting in a low secondary aerosol formation potential.Our experimental results indicated that the in situ measurement of the secondary aerosol formation potential could provide important information for evaluating the contributions of local emission and long distance transport to the aerosol pollution.     

成都市黑碳气溶胶污染特征及与气象因子的关系

为系统了解成都市黑碳气溶胶(BC)的污染特征,利用四川省环境监测站提供的成都市人民南路四段2013年9月至2014年7月逐时BC监测数据,对其浓度进行了统计分析。结果表明:1)BC小时平均浓度变化范围较大,介于0.01~57.83μg/m3,浓度中值(5.17μg/m3)小于平均值(7.32μg/m3),即BC小时浓度具有偏态分布特征。2)BC日均浓度变化范围为2~28.2μg/m3,其浓度日变化在四季均呈明显的单谷型,谷值出现在16:00时附近,表现为从凌晨到10:00时变化较平稳,10:00—16:00时浓度急剧下降,16:00到夜间浓度急剧上升;浓度季变化呈现出冬高夏低,春秋平稳的基本特征。3)秋、冬、春、夏四季BC本底浓度值分别为2.49,5.05,2.89,2.43μg/m3。4)BC质量浓度与PM2.5和PM10变化趋势一致,BC浓度相对颗粒物浓度变化较快,在0.01水平上与PM2.5和PM10均呈显著正相关,相关系数分别为0.657、0.638,与温度、降水和风速均呈负相关,相关系数分别为-0.334,-0.338,-0.202。     

华北平原夏收期间气溶胶卫星遥感探测分析

为研究2014年华北平原在夏收期间气溶胶污染的时空分布特征及形成原因,对2014年6月MODIS卫星的华北平原的气溶胶光学厚度(AOD)、细粒子比(FMF)、火点分布及后向轨迹进行了分析.结果表明,2014年6月华北平原的气溶胶光学厚度值在1.2~2.0之间,远高于年平均值1.0~1.2,而6月的火点分布主要集中在6—14日,此阶段的气溶胶光学厚度值高于6月6日前及14日以后的气溶胶光学厚度值.在两个特定研究区——华北南部及长三角地区,通过对6月的3个阶段的细粒子比进行分析,发现火点集中阶段细粒子排放增多,确定此次污染极有可能是由秸秆燃烧造成.在火点集中时期,两个研究区的后向轨迹说明,污染主要来自火点分布密集区域,进一步确定了秸秆燃烧是华北平原在夏收期间的主要污染源之一.     

广州市不同粒径大气颗粒物有机提取物的致突变性研究

为了了解广州市大气气溶胶中不同粒径颗粒物中有机物的污染水平以及其对人体健康的影响 ,用 6段分级采样器分段采集 相似文献   

北京市大气细粒态气溶胶的化学成分研究

2000年6月在北京北郊中国科学院大气物理所气象塔观测场采集了大气中细粒态气溶胶样品.用质子诱导X射线荧光分析法(PIXE)对样品进行了分析,得到Al、Si、P、S、Cl、K等19种元素的浓度及其谱分布并对当前北京市大气气溶胶的来源、化学元素成分的变化进行了研究.结果表明,这19种元素中的许多元素的浓度与过去相比有不同幅度的降低,说明北京市对大气污染的防治是有效果的.     

Aerosol Properties Over Japan Determined by Sun/Sky Photometry

The field-experiment campaigns of the Asian Atmospheric Particulate Environment Change Studies (APEX-E1 in December 2000, -E2 in spring 2001, and -E3 in spring 2003) aimed at understanding Asian aerosols. Our sun/sky photometric measurements of atmospheric light have joined these campaigns by using multispectral photometers (CE-318-1 and -2, Cimel Electronique; and POM-100P, Prede) at Noto, Shirahama, and Fukue-jima, Japan. This paper focuses on aerosol retrieval during the APEX-E3 campaign. Aerosol optical thickness, Ångström exponent, single-scattering albedo and the refractive index derived from these ground-based measurements can be classified into three categories of aerosols: (1) an oceanic type of typical background aerosols over Japan, (2) an anthropogenic type, and (3) a soil-dust type. The data from APEX experiments demonstrate that aerosols over Japan exhibit complicated spatial and temporal features involving mixtures of compounds.     

兰州市不同季节大气微生物气溶胶粒径及分布特征研究

大气微生物对人类危害不仅与微生物气溶胶浓度和种类有关,而且大气微生物气溶胶粒径尺度大小及其分布特征也是重要的影响因素.在兰州市城关区选取不同环境功能区对其室外大气微生物气溶胶粒径(D,μm)大小及分布特征进行研究,结果表明,不同环境功能区大气细菌、霉菌和放线菌气溶胶粒度分布特征存在季节性分布差异,其中大气细菌气溶胶粒径...     

A Contribution to the Study of the Antidust Respirators’ Real Performance

In most industrial enterprises, hazardous factors are present in quantities exceeding permissible levels. Such a situation requires using antidust respiratory protection. It has been suggested, however, that filters for respirators are not assessed properly and that lab results might not be related to real filtering efficiency in industry. This article contains test results of some commercially available filtering half-masks, including the effect of loading with real dust, high humidity, high temperature, and a combination of loading with dust and high humidity on the half-masks’ performance. The results show that the effect of these factors is considerable and that a combination of loading with silica dust and exposing to high humidity can cause a complete loss of performance.     

Deposition and Resuspension of Selected Aerosols Particles on Electrically Charged Filter Materials for Respiratory Protective Devices

The primary aim of the study was to analyse the non-steady state of filtration for selected electrostatic filter materials designed for use in respiratory protective devices. The obtained results showed that the filtration process in electrostatic filters was dependent in the main on the following factors: type of the filter material, electrostatic field strength of the material, and the charge of the aerosol.

To a lesser degree the filtration process depended on the sign of the charge and the relative humidity of the air. A significant correlation was found between the increase in the penetration and the decrease in breathing resistance while the filter was being loaded.

The effect of resuspension (tearing off and re-deposition of dust agglomerates inside the filter) on the filtration process very significant. It was also observed that under certain conditions electrostatic filter materials lost their protection properties.     

V-shaped substrate for surface and volume enhanced Raman spectroscopic analysis of microplastics

● V-shaped substrate was obtained for SERS analysis of microplastics (diameter ≈ 1 μm). ● Enhancement factor of V-shaped substrate can reach 20 in microplastics detection. ● V-shaped nanopore array can bring additional volume enhancement. ● V-shaped substrate was more economic in application compared to Klarite substrate. Research on the microplastics (MPs) is developing towards smaller size, but corresponding methods for the rapid and accurate detection of microplastics, especially nanoplastics still present challenge. In this work, a novel surface and volume enhanced Raman spectroscopy substrate was developed for the rapid detection of microplastic particles below 5 μm. The gold nanoparticles (NPs) were deposited onto the surface and into the V-shaped nanopores of anodized aluminum oxide (AAO) through magnetron sputtering or ion sputtering, and then AuNPs@V-shaped AAO SERS substrate was obtained and studied for microplastic detection. SERS performance of AuNPs@V-shaped AAO SERS substrate was evaluated through the detection of polystyrene and polymethyl methacrylate microspheres. Results indicated that individual polystyrene sphere with a diameter of 1 μm can be well detected on AuNPs@V-shaped AAO SERS substrate, and the maximum enhancement factor (EF) can reach 20. In addition, microplastics in ambient atmospheric samples were collected and tested to verify the effectiveness of the AuNPs@V-shaped AAO SERS substrate in the real environment. This study provides a rapid, economic and simple method for detecting and identifying microplastics with small size.