中国工业烟粉尘排放时空演化及其影响因素

采用空间分析和空间杜宾模型等方法,研究1999—2017年中国工业烟粉尘排放时空演化特征及其影响因素。结果表明：① 中国工业烟粉尘排放空间分布差异明显,其排放的基尼系数和污染物分布指数均呈现下降态势,空间集中程度有所缓和。② 中国工业烟粉尘排放空间分布呈东北?西南走向,其排放中心不断由东南向西北方向迁移。③ 中国工业烟粉尘排放存在空间相关性和空间溢出效应,其冷热点区空间分布发生显著变化。④ 能源消耗、第二产业比重、人口密度和经济发展水平的提升将会增加工业烟粉尘排放,而外资水平、治理技术水平和环境规制力度的提升则有利于减少工业烟粉尘排放。     

北京、郑州和深圳三城市空气中气溶胶单颗粒特征的扫描电镜分析

分别采集北京、深圳和郑州3个城市气溶胶样品,使用场发射扫锚电镜-能谱仪观察气溶胶单颗粒的显微形貌和元素组成,并利用图像分析系统对PM2.5的粒径进行了分析。结果表明,城市气溶胶单颗粒类型以矿物颗粒、烟尘和球形颗粒(飞灰和二次粒子)为主。对比3个城市气溶胶中不同颗粒类型数量百分比发现,矿物颗粒数量最多的城市是北京,飞灰和烟尘数量最多的城市是郑州,而规则矿物颗粒数量最多的城市是深圳。3个城市气溶胶单颗粒的数量-粒径分布均呈单峰分布。深圳气溶胶中颗粒物的粒径相对较小,其次为郑州、北京。3个城市气溶胶中颗粒物来源不同程度上都受到交通污染源影响,而燃煤源对北京和郑州气溶胶中颗粒物来源影响仍然不容忽视。     

Refractory Black Carbon Results and a Method Comparison between Solid-state Cutting and Continuous Melting Sampling of a West Antarctic Snow and Firn Core

This work presents the refractory black carbon(rBC)results of a snow and firn core drilled in West Antarctica(79°55'34.6"S,94°21'13.3"W)during the 2014?15 austral summer,collected by Brazilian researchers as part of the First Brazilian West Antarctic Ice Sheet Traverse.The core was drilled to a depth of 20 m,and we present the results of the first 8 m by comparing two subsampling methods—solid-state cutting and continuous melting—both with discrete sampling.The core was analyzed at the Department of Geological Sciences,Central Washington University(CWU),WA,USA,using a single particle soot photometer(SP2)coupled to a CETAC Marin-5 nebulizer.The continuous melting system was recently assembled at CWU and these are its first results.We also present experimental results regarding SP2 reproducibility,indicating that sample concentration has a greater influence than the analysis time on the reproducibility for low rBC concentrations,like those found in the Antarctic core.Dating was carried out using mainly the rBC variation and sulfur,sodium and strontium as secondary parameters,giving the core 17 years(1998?2014).The data show a well-defined seasonality of rBC concentrations for these first meters,with geometric mean summer/fall concentrations of 0.016μg L^?1 and geometric mean winter/spring concentrations of 0.063μg L^?1.The annual rBC concentration geometric mean was 0.029μg L^?1(the lowest of all rBC cores in Antarctica referenced in this work),while the annual rBC flux was 6.1μg m^?2 yr^?1(the lowest flux in West Antarctica records so far).     

Characterisation of Soot Emitted by Domestic Heating,Aircraft and Cars Using Diesel or Biodiesel

The characterisation of aggregates, like soot, firstly requires the determination of the size distribution of the primary particles. The primary particle size of combustion generated aggregates depends upon the combustion environment and the formation conditions, such as temperature, pressure and fuel-to-air ratio, among others. Since the combustion characteristics are different in the different types of burners, the characterisation of primary particles may offer the possibility to distinguish soot from different sources. In this paper, we present the signature of the primary particles and the aggregates of soot emitted by cars using diesel or biodiesel, by domestic heating, and by aircraft exhausts, which can be considered as the major sources as derived from measurements on transmission electron micrographs. The size distributions of all aggregates types with different aerodynamic diameter were log-normal and quasi-monodisperse. The size distribution of the primary particles for soot emitted by different sources showed minor differences. However, a comparison between the diameter of the primary particles and those obtained using a standard method for carbon black revealed discrepancies. The median diameter of the primary particles was combined with the median number of primary particles in an aggregate to calculate the relative particle surface area available for adsorption. In a similar way, the relative specific surface area was determined. The surface area was measured using the Brunauer-Emmett-Teller (B.E.T.) nitrogen adsorption method and the relative surface area available for adsorption was calculated.     

Heterogeneities in the Microstructure and Composition of Aircraft Engine Combustor Soot: Impact on the Water Uptake

Size, morphology, microstructure, chemical composition and hygroscopic properties of aircraft engine combustor (AEC) soot particles are studied by using a combination of several methods, namely atomic force microscopy, transmission electron microscopy, gravimetry, ionic chromatography analysis and wetting observations. From the microstructure and the composition of soot agglomerates, we find that we can separate AEC soot in two fractions having quite different physico-chemical properties: a main fraction of particles containing essentially amorphous carbon with small amounts of oxygen, sulfur and iron and a fraction of impurities characterized by various structures and a large amount of impurities. These properties of aircraft engine combustor soot are compared to those of soot obtained by burning TC1 aviation kerosene in a laboratory burner. It is shown that TC1 soot can be a good surrogate of the AEC main fraction. Such a finding allows us to perform water uptake measurements and to conclude that the AEC main fraction is rather hydrophobic whereas the AEC fraction of impurities is highly hydrophilic The ability of the two fractions of aircraft engine combustor soot to act as cloud condensation nuclei is discussed with respect to their implication in contrail and cirrus formation.Associated to Université de la Méditerranée (Aix-Marseille II) and to Université Paul Cézanne (Aix-Marseille III)     

Gas and Particle Partitioning Behavior of Aldehyde in the Presence of Diesel Soot and Wood Smoke Aerosols

Outdoor smog chamber experiments were performed to investigate gas/particle (G/P) partitioning behavior of aldehyde compounds in atmospheric acidic aerosols. Diesel soot and wood smoke aerosols were selected as acidic aerosols and octanal, decanal, undecanal, and cis-pinonaldehyde for aldehydes compounds. Aerosol acidity was measured with the equivalent sulfuric acid amounts in aerosol mass: 0.2–0.6 wt% in diesel soot and 0.04–0.1 wt% in wood smoke aerosols. Experimentally determined partitioning coefficients of aldehyde along with other classes of semivolatile organic compounds (SOCs) were compared with the estimation. All experimental G/P partitioning coefficients of aldehyde compounds were 10–200 times higher than estimated partitioning coefficients. Aldehyde partitioning coefficients in wood soot were similar or less than diesel soot aerosols.     

天津武清地区单颗粒黑碳气溶胶特征观测分析

该文介绍了单颗粒黑碳测量仪的观测原理,该仪器利用红外波段的连续激光束对黑碳粒子加热并使之燃烧,通过粒子发出的散射光信号和黑碳粒子燃烧时发出的光信号,来分析每一个黑碳粒子的特性,并通过两种信号的时间差判断黑碳粒子的混合状态。其原理有别于传统的黑碳气溶胶观测方法,可以提供单个黑碳气溶胶粒子特性信息。2009年12月使用单颗粒黑碳测量仪在天津市武清地区进行了为期近1个月的观测。结果表明:粒径为50~500 nm的气溶胶粒子中,黑碳气溶胶粒子占57.2%,平均数浓度为1504 cm-3,黑碳气溶胶粒子的平均质量浓度为8.15 μg/m3,包衣较厚的混合型黑碳气溶胶粒子占黑碳气溶胶粒子的51.5%。     

Paleolimnological evidence for the recent acidification of Llyn Hir,Dyfed, Wales

A variety of paleolimnological techniques, coupled with historical data on land-use and fisheries, are used to evaluate the magnitude, timing, and causes of acidification of Llyn Hir, a moorland lake in central Wales. pH reconstruction based on diatom analysis suggests a gradual decline in lakewater pH beginning ca. 1870 and intensifying in the mid-1930's, with a total decline of 1.1 pH units between 1870 and 1984. This pH decline correlates with increased sedimentary concentrations of carbonaceous particles, trace metals, and magnetic minerals, which indicate the local deposition of atmospherically transported products of fossil-fuel combustion. Pollen data and the historical record show no significant alterations in land-use or catchment vegetation, indicating that acidification of Llyn Hir is a result of the increased deposition of atmospheric pollutants, not of land-use and vegetation change.Limnological Research Center Contribution No. 374.     

吉林省粉煤灰的物理和化学特征

首次对吉林省10个大中型热电厂的粉煤灰特征进行较系统的研究,查明了各热电厂粉煤灰的化学成分、物理性质（密度、堆积密度、实密度、粒度）和物质组成。这些特征作为商品粉煤灰的重要经济技术参数决定粉煤灰利用方向,所以该项研究具有重要的意义。     

不同成熟度家用蜂窝煤燃烧排放烟炱颗粒的Py-GC/MS研究

主要利用热解-气相色谱/质谱联用技术(Py-GC/MS)对不同成熟度的家用蜂窝煤燃烧排放烟炱(soot)颗粒的化学特征进行研究,并探讨了成熟度对燃煤排放soot颗粒热解产物的影响。结果显示:不同成熟度的燃煤排放soot颗粒热解产生类似的产物。这些化合物均以芳香化合物(58.1%～92.0%)为主,另外还含有酚类化合物(0.66%～32.3%)、脂肪烃(0.21%～9.57%)、呋喃类化合物(1.42%～2.57%)、含硫化合物(NA～4.12%)和含氮化合物(NA～3.91%)等,表明不同成熟度蜂窝煤燃烧排放的soot颗粒都是以高度芳香性的结构为核心,连接有含氧、氮等杂原子基团组成。研究结果还显示,原煤成熟度对soot颗粒的热解特征具有一定的影响。总体上,soot颗粒热解产物中芳香化合物的百分含量随着煤样成熟度的增加呈现递增趋势,而酚类化合物的百分含量则随着煤样成熟度的增加逐渐降低,另外含氮化合物主要存在于低成熟度煤样燃烧排放的soot颗粒样品中。本文研究结果表明了随着煤成熟度的升高,燃烧排放的soot颗粒的芳香性逐渐增强,含O、N等不稳定结构逐渐减少。含硫化合物是燃煤排放soot颗粒的特征化合物,主要存在于高成熟度燃煤排放的soot颗粒中。这些结果对于了解不同成熟度的燃煤排放soot颗粒样品中分子结构和组成具有重要的意义。