共查询到18条相似文献，搜索用时 328 毫秒
1.
为探究青藏高原东南部大气中多环芳烃(Polycyclic Aromatic Hydrocarbons,简称PAHs)的污染、源及输送特征,利用鲁朗地区(29.77°N,94.73°E)总悬浮颗粒物(Total Suspended Particles,简称TSP)和大气中的14种PAHs含量,结合同期气象环境数据进行了综合分析。结果表明,该地区TSP中PAHs和气相的PAHs质量浓度变化范围分别为0.22～5.05 ng m-3和0.83～63.75 ng m-3,平均值分别为2.13 ng m-3和11.33 ng m-3。薪柴和柴油的燃烧是污染的主要方式,汽油燃烧等其他排放为次要方式。PAHs来自本地污染和远距离传输(Long Range Transmission,简称LRT)共同的影响。本地污染在四季各个源地均不相同。冬春季本地污染大,源在东南及正南方,夏秋季受本地和外来输送共同作用,本地源在东南方且占比小,LRT占比大。LRT受西北气流、西风气流和西南气流三支气流影响,污染严重时西南气流占主导... 相似文献
2.
利用2010年8月采集的南京北郊气溶胶样品,使用GC-MS对美国环保总局推荐的16种优先控制的多环芳烃含量、分布特征进行了研究。在此基础上,用特征比值法、主因子分析法分析得到南京市北郊大气中PAHs的主要来源为车辆尾气、燃煤、天然气和草木秸秆燃烧,并应用绝对因子分析法进一步定量计算主要源对PAHs的浓度贡献率。结果表明:1)大气颗粒物中16种多环芳烃的平均总质量浓度为135.85 ng/m~3,多环芳烃以4环为主,在可吸入颗粒物中的浓度占总浓度的88.7%;2)PM10中多环芳烃呈双模态分布,在9~10μm的粗模态和0.65~1.10μm的积聚模态上各出现一个峰值;3)天然气等对PAHs的贡献率为5.7%~44.1%,燃煤源的贡献率为20.7%~57.8%,汽车尾气的贡献率为4.6%~46.7%,木材燃烧的贡献率为2.9%~38.1%。本地交通排放和燃料燃烧是南京北郊大气颗粒物中PAHs的主要来源,远距离输送也对南京北郊气溶胶中的PAHs有重要贡献。 相似文献
3.
研究了南京2009—2010年大气粗、细粒子中PAHs(多环芳烃,Polycyclic Aromatic Hydrocarbons)在四季不同的组成特征及来源。结果表明,南京细粒子中PAHs的浓度范围是19.11~131.31 ng/m~3,而粗粒子是17.77~134.85 ng/m~3。局地排放与区域传输的综合作用,使得南京不同采样点的PAHs浓度相关度较高,具有相同的污染源及污染过程。除了秋季PAHs主要分布于粗粒径段,南京大气中PAHs以细粒子为主。春、冬季分别受到了来自ENE-S和NNW-NE方向污染气团的远距离输送影响,夏季局地排放的污染物受到了西南清洁气团的稀释作用,秋季不同于其他季节,仅以局地贡献为主。源解析结果显示,不同季节PAHs来源存在差异,最主要的排放源是机动车源,其次是燃煤/焦化,秋季受较多的生物质燃烧贡献。秋季特殊的排放源贡献,以及局地贡献为主的污染形式,可能是其浓度分布不同于其他季节的根本原因。 相似文献
4.
采用高效液相色谱法对沈阳市地表土壤中的多环芳烃（Polycyclic Aromatic Hydrocarbons,PAHs）进行了定量分析,研究了沈阳市地表土壤中PAHs在不同功能区的含量及分布特征。结果表明：从土壤PAHs总量来看,居民区最低,其次是商业区,交通干道、文教区和公园排在商业区之后,工业区的PAHs总量最多;从PAHs的空间差异来看,靠近工业区以及机动车车流量较大的地区PAHs含量较高,靠近文教区和居住区的地区PAHs含量较低;从PAHs种类来看,所有功能区样品中PAHs的组分分布状况较为一致,以四环PAHs含量最多,其次是五环PAHs和三环PAHs;参考美国EPA沉积物PAHs质量标准和治理标准,沈阳市内五区PAHs总量超过质量标准的功能区有工业区、交通干道（4个采样点,占比36.3%）、文教区（3个采样点,占比75%）和公园区（4个采样点,占比40%）,超过治理标准的功能区有工业区,公园区（1个采样点,占比10%）,文教区（1个采样点,25%）。 相似文献
5.
在沈阳市选取7个主要公园,于2017年3月采集土壤样品,采用高效液相色谱法对15种美国环保署优控多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)的浓度进行分析。结果表明:2017年沈阳市各公园PAHs的污染特征不同,主要污染成分差别明显,其中万泉公园土壤污染水平最高,土样中PAHs浓度远高于其他采样点。由纵向分析发现,沈阳市各公园PAHs浓度随着土壤深度增加呈下降的趋势。由沈阳市各公园土壤样品中PAHs不同环数所占百分比可知,中、高环数污染物组分含量普遍较高而低环数污染物组分含量均较少,表征各公园土壤污染源主要为燃料燃烧。通过比值法进一步分析可知,沈阳市各公园土壤中PAHs来源主要为燃料的高温燃烧,燃烧源主要为煤、石油类、生物质燃烧的混合源。 相似文献
6.
为研究石家庄市采暖期与非采暖期大气细颗粒物(PM2.5)中多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)的污染特征及其人群健康效应,采集了石家庄市2017年1月—2019年12月每月10—16日PM2.5样品,使用气相色谱-质谱联用仪测定PM2.5中优先控制的16种多环芳烃的浓度,分析采暖期与非采暖期PM2.5中多环芳烃的污染水平及组成特征,利用特征比值法和主成分分析法对其来源进行定性判断,并采用健康风险评估模型以及预期寿命损失评估多环芳烃对人群的健康风险。结果表明：(1)PM2.5及其中多环芳烃浓度平均水平在采暖期分别为106.00μg/m3、44.17 ng/m3,非采暖期分别为73.00μg/m3、40.17 ng/m3。16种多环芳烃中含量最高的是苯并[a]芘,其次为苯并[k]荧蒽、苯并[b]荧蒽、?。多环芳烃单体环数越高其致癌作用越强,不同环... 相似文献
7.
南京冬季持续性强浓雾天气中三级分档雾水的理化特性分析 总被引：1，自引：0，他引：1
2013年12月7—9日南京出现持续性强浓雾天气过程。利用观测试验中获取的三级分档雾水和分粒径气溶胶的水溶性离子浓度,气溶胶数浓度谱、雾滴谱以及自动气象站获取的气象要素等资料,通过对比研究浓雾过程中4—16 μm（3级）、16—22 μm（2级）、>22 μm（1级）3个粒径范围雾滴（雾水）与分粒径气溶胶的微物理特征和化学特性,探讨不同粒径气溶胶粒子吸湿增长对雾滴的贡献以及气溶胶离子组分对不同尺度雾滴化学性质的影响。结果表明,在强浓雾天气中,能见度为50 m左右,短波辐射减弱形成稳定逆温层,有助于污染气溶胶的累积并吸湿增长向雾滴转化。雾滴的增加主要集中在小滴范围, 直径在0.5—1 μm的气溶胶粒子对其贡献最大。各粒径段气溶胶中阴离子NO3-和SO42-均表现出较高值,阳离子中Ca2+浓度最高。三档雾水中各阴、阳离子浓度均在4—16 μm小滴雾水中最高,16—22 μm中滴雾水和>22 μm大滴雾水的阴、阳离子浓度没有明显的高低之分。阳离子中Ca2+的浓度在第1级小滴雾水中最高,2级和3级雾水中NH4+的浓度最高,阴离子中NO3-和SO42-在各级雾水中浓度相差不大。雾水pH值2.7—6.9,呈酸性,小雾滴酸性更强。 相似文献
8.
中国近30a臭氧气候场特征 总被引：3，自引：1，他引：2
利用1979—2005年TOMS（total ozone mapping spectrometer）和2006—2007年OMI（ozone mo-nitoring instrument）的卫星观测资料,分析中国地区对流层臭氧含量（tropospheric ozone residue,TOR）、整层臭氧含量（total ozone,TO）的空间分布和季节变化特征,利用二项式加权平均法、Mann-Kendall突变检验法以及小波分析法分析南方典型地区广州臭氧序列的趋势、突变以及周期特征。结果表明,中国地区多年平均对流层臭氧柱含量为35.89DU,东中部地区高于西部,四川东部和重庆西部存在极高值区,青藏高原为极低值区;对流层臭氧夏季平均值最高,冬季最低,春季高于秋季。中国地区多年平均臭氧总量为298.61DU。臭氧总量随着纬度增大而增大,成带状分布,青藏高原为极低值区;臭氧总量春季平均值最大,秋季为最低。南方广州地区的对流层臭氧在1979—2007年之间存在明显的上升趋势,时间变率为0.38DU/（10a）;TOR时间序列在1997年发生突变,存在显著的1a及2a的周期。臭氧总量在1979—2007年之间存在明显的下降趋势,变化率为-2.1DU/（10a）;TO在1993年发生突变,存在显著的2a周期 相似文献
9.
庐山2016年冬季三级分档雾水化学特征 总被引：1，自引：0，他引：1
探究不同尺度雾滴化学特征是深化雾微物理化学研究的重要内容。2016年12月—2017年1月在庐山开展雾综合观测实验,利用主动式三级分档雾水采集器（CASCC 3_stage）收集到3次雾过程73个分档雾水样本,雾滴分档粒径:4—16 μm（3级）,16—22 μm（2级）和≥22 μm（1级）。定量得到了分档雾水的pH、电导率（EC）及9种水溶性无机离子（Na+、NH4+、K+、Mg2+、Ca2+、Cl-、NO2-、NO3-、SO42-）浓度（μeq/L）。结果表明,庐山冬季雾水酸化严重,pH为3.96—5.82,pH < 5.6的样品占98.6%且直径4—16 μm小雾滴的强酸性（pH < 4.5）样品最多,占比达54.2%,小雾滴酸性和电导率更强;NH4+、Ca2+、NO3-、SO42-是雾水的主要离子组分,[NH4++Ca2++NO3-+SO42-]分别在三级分档雾水中占总离子浓度（TIC）的83.8%、88.0%和88.7%;综合3次雾过程,总离子浓度、NH4+、K+、NO3-、SO42-在4—16 μm小雾滴存在富集,表现出尺度依赖特征;86%雾水样品[SO42-]/[NO3-]介于0.5—3.0,属于硫酸和硝酸混合型酸化,雾水酸化主要原因是碱性缓冲物质与酸性组分不平衡以及可能存在有机酸贡献;同一观测点不同雾过程化学特征存在个例差异,第二次雾过程（12月25日14时—26日21时）（北京时）,总离子浓度、NH4+、Ca2+、NO3-、SO42-在16—22 μm尺度雾滴存在富集,这可能是雾区气溶胶浓度较低、降温、采样间隔和污染气体及气溶胶输送共同作用的结果。后向轨迹聚类和潜在源（PSCF）分析表明,观测期间影响庐山的气团均来自西部,来自湖南北部的局地气团占总轨迹数的68.99%,最为重要;PM2.5、SO2、NO2具有相似潜在源区空间分布,主要位于湖北、湖南、安徽西南部和江西北部等邻近省份地区,以近距离输送为主。 相似文献
10.
A total of 11 PM2.5 samples were collected from October 2003 to October 2004 at 8 sampling sites in Beijing city. The PM2.5 concentrations are all above the PM2.5 pollution standard （65 μg m^-3） established by Environmental Protection Agency, USA （USEPA） in 1997 except for the Ming Tombs site. PM2.5 concentrations in winter are much higher than in summer. The 16 Polycyclic aromatic hydrocarbons （PAHs） listed as priority pollutants by USEPA in PM2.5 were completely identified and quantified by high performance liquid chromatography （HPLC） with variable wavelength detector （VWD） and fluorescence detector （FLD） employed. The PM2.5 concentrations indicate that the pollution situation is still serious in Beijing. The sum of 16 PAHs concentrations ranged from 22.17 to 5366 ng m^-3. The concentrations of the heavier molecular weight PAHs have a different pollution trend from the lower PAHs. Seasonal variations were mainly attributed to the difference in coal combustion emission and meteorological conditions. The source apportionment analysis suggests that PAHs from PM2.5 in Beijing city mainly come from coal combustion and vehicle exhaust emission. New measures about restricting coal combustion and vehicle exhaust must be established as soon as possible to improve the air pollution situation in Beijing city. 相似文献
11.
PM10 samples from a garden site (site A), an industrial-traffic intersection (site B), a residential site (site C) and an island site (site D) were collected at December 21–29, 2004; March 18–22, 2005; July 4–13, 2005 and October 24–28, 2005 in Xiamen. 15 priority PAHs compounds were analyzed by using a gas chromatograph/mass spectrometer (GC/MS). The abundance and origin of PAHs are discussed to reveal seasonal variations in Xiamen air quality. Average concentrations of Σ15PAHs were 17.5 ng/m3, 3.7 ng/m3, 32.6 ng/m3 and 10.5 ng/m3 from spring to winter with the highest value in autumn. The dominant PAHs components in every season were low and middle molecular weight PAHs including phenanthrene, pyrene, fluoranthene and chrysene. Diagnostic ratios and PCA analysis identified the main sources of particle bound PAHs: mainly from both gasoline and diesel vehicles exhaust, with some contribution from coal combustion, industry emission and cooking sources. 相似文献
12.
The concentrations of particulate Polycyclic aromatic hydrocarbons (PAHs) were measured at Gosan, a background site in Korea for 1 year between November 2001 and November 2002. The total concentrations of 14 PAH compounds at Gosan were between 0.52 and 14.76 ng m− 3 and about 3–15 times higher than those at other rural or remote sites in the world. Seasonal trend was observed for particulate PAHs concentrations at Gosan with higher levels during heating season due to increased fossil fuel usage and the movement of air parcels from Asian continent. Principal component factor analysis (PCF) for PAHs showed three factors; combination of coal combustion and vehicular emission, natural gas combustion, and unidentified one. However, PCF for the combined data of PAHs, inorganic ions, and elements revealed that the unidentified factor consists of crustal species, sea salts, and four PAH compounds. Thus, this factor is thought to be transport of crustal species with organics from combustion sources. The major variables which determine the sources of PAHs are the heating season and the movement of air parcels from Asian continent. 相似文献
13.
基于国家气候中心中等分辨率模式版本BCC-CSM2-MR开展的第六次耦合模式比较计划(CMIP6)模拟结果, 首先利用辽河流域80个气象站点观测资料对模式的性能进行了评估, 然后分析了未来不同共享社会经济路径(SSP)情景下的气温降水变化趋势。结果表明: 模式能较好的模拟气温和降水的月、季、年变化, 模拟的气温较观测气温偏低, 模拟的降水略偏多; 模式对秋季和冬季气温的模拟性能明显优于夏季和春季, 对夏季降水的模拟性能较好。模式较好地模拟了辽河流域气温南高北低的纬向分布以及降水自东南向西北逐渐减少的空间分布形势, 较好地模拟出辽河流域冷暖中心位置, 模拟的降水偏少地区位于辽河流域水系稀疏地区。相对于基准期(1995—2014年), 未来辽河流域气温、降水基本呈增加趋势, 未来不同时期不同情景气温增幅均表现为平均最低气温>平均气温>平均最高气温, 冬季和春季增温幅度较大, 夏季降水量增幅最显著。随着排放情景升高, 平均气温和平均最低(最高)气温增幅持续增大, 显著增温地区集中于辽河流域东北部。SSP1-2.6和SSP2-4.5情景下预估降水的增幅自西南向东北递减, 降水增加大值区位于辽宁西部; SSP3-7.0和SSP5-8.5情景下降水增幅自西向东逐渐递减, 降水增幅显著区域位于辽河流域上游的内蒙古和辽宁西部。 相似文献
14.
Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in urban air samples of Konya, Turkey between August 2006 and May 2007. The concentrations of pollutants in both the gas and particulate phase were separately analysed. The average total (gas + particulate) concentrations of PAHs, PCBs and OCPs were determined as 206 ng m− 3, 0.106 ng m− 3, 4.78 ng m− 3 respectively. All of the investigated target compounds were dominantly found in the gas phase except OCPs. Higher air concentrations of PAHs were found at winter season while the highest concentrations of PCBs were determined in September. The highest OCPs were detected in October and in March. In urban air of Konya, PCB 28 and PCB 52 congeners represent 46% and 35% of total PCBs while Phenanthrene, Fluoranthene, Pyrene accounted for 29%, 13%, 10% of total PAHs. HCH compounds (α + β + γ + δ-HCH), total DDTs (p,p′-DDE, p,p′-DDD, p,p′-DDT), Endosulfan compounds (Endosulfan I, Endosulfan II, Endosulfan sulfate) were dominantly determined as 30%, 21%, 20% of total OCPs respectively. Considering the relation between these compounds with temperature, there was no significant correlation observed. Despite banned/restricted use in Turkey, some OCPs were determined in urban air. These results demonstrated that they are either illegally being used in the course of agricultural activity and gardens in Konya or they are residues of past use in environment. According to these results, it can be suggested that Konya is an actively contributing region to persistent organic pollutants in Turkey. 相似文献
15.
松花江、辽河流域实测径流的变化趋势及其与降水的关系 总被引：1，自引：0，他引：1
利用松花江、辽河流域内132个降水测站1961-2000年40年的月降水资料,以及水文测站哈尔滨、江桥、铁岭1956-2000年45年的月实测径流量资料,分析松花江、辽河流域实测径流的变化趋势,并探讨夏季径流与同期降水的相关性。结果表明：松花江流域的年实测径流量呈现较微弱的下降趋势,而辽河流域年实测径流呈现显著的下降趋势;两流域径流量均存在着一致的阶段性丰枯周期变化;最显著的一次波动是夏季实测径流由20世纪60年代中后期呈现的显著下降趋势转为80年代初期的明显上升趋势;降水是影响松花江、辽河流域夏季实测径流的一个重要气候因素。初步揭示了人类活动、下垫面改变对实测径流的影响。 相似文献
16.
Emissions of Polycyclic aromatic hydrocarbons by savanna fires 总被引：2，自引：0，他引：2
Pierre Masclet Hélène Cachier Catherine Liousse Henri Wortham 《Journal of Atmospheric Chemistry》1995,22(1-2):41-54
Although Polycyclic aromatic hydrocarbons (PAH) are known as anthropogenic compounds arising from the combustion or the pyrolysis of fossil fuels, they may be also emitted by the combustion of vegetation. A field study was carried out in January 1991 at Lamto (Ivory Coast) as part of the FOS DECAFE experiment (Fire Of Savanna). Some ground samplings were devoted to the qualitative and quantitative characterization of atmospheric emissions by savanna fires during prescribed burns and under background conditions. Specific collections for gaseous and particulate PAHs have shown that the African practice of burning the savanna biomass during the winter months is an important source of PAHs. These compounds are emitted mainly in gaseous form but a significant fraction, essentially heavy PAHs, is associated with fine carbonaceous particles and can therefore represent a hazard for human health, since some of these compounds are mutagenic and carcinogenic. Twelve compounds were identified during the fire episodes and in the atmospheric background. The total concentration in the fires is of the order of 10 ng m–3 for the gas phase and from 0.1 to 1 ng m–3 in the aerosols. In the atmospheric background the mean concentrations are regular, 0.15 ng m–3 and 2 pg m–3, respectively. These concentrations are comparable with what is observed in European rural zones. The particulate emissions of PAHs by the savanna fires are distinguished by the abundance of some compounds which can be considered as tracers, although they are also slightly emitted by fossil fuel sources. These compounds are essentially pyrene, chrysene and coronene. In the gas phase, although no individual PAH may be considered as specific of the biomass combustion emissions, the relative abundances of the main PAHs are characteristic of the biomass burning. The concentrations of pyrene and fluorene are always predominant; these compounds could be considered as characteristic emission products of smoldering and flaming episodes, respectively. In the background the PAH composition shows that in a tropical region the air consists of a mixture coming from the various sources, but the biomass combustion is by far the most important source.The fluxes of total PAH emitted by savanna biomass burning in Africa were estimated to be of the order of 17 and 600 ton yr–1, respectively, for the particulate PAHs and the gaseous PAHs, respectively. 相似文献
17.
Ximei Hou Guoshun Zhuang Yanfen Lin Juan Li Yilun Jiang Joshua S. Fu 《Journal of Atmospheric Chemistry》2008,61(2):119-131
The indoor PM2.5 aerosol samples for charcoal broiling source under Chinese traditional charbroiling and the ambient fine aerosols samples
(PM2.5) were collected in Beijing to investigate the characteristics of the charcoal broiling source and its impact on the fine
organic aerosols in the atmosphere. The concentrations of 20 species of the trace organic compounds, including polycyclic
aromatic hydrocarbons (PAHs), fatty acids, levoglucosan, and cholesterol in PM2.5 were identified and quantified by GC/MS. The total PAHs and fatty acids emitted from charcoal broiling to PM2.5 were 8.97 and 87,000 ng mg−1 respectively. The concentrations of the light molecular weight (LMW) 3- and 4-ring PAHs were much higher than those of the
high molecular weight (HMW) 5- and 6-ring PAHs. Fatty acids were the most abundant species in source profile, accounting for
over 90% of all identified organic compounds. More polyunsaturated fatty acid (linoleic acids) than the saturated fatty acid
(stearic acids) emitted in the cooking. Charcoal broiling is a minor source of PAHs compared to the source of biomass burning.
Comparing the ratios of levoglucosan/fatty acid and levoglucosan/cholesterol in the charcoal broiling samples to the ambient
samples, it is evident that meat cooking is an important source of fatty acids, but a less important source of cholesterol.
Cooking, as one of the source of fine organic particles, plus other anthropogenic sources would be related to the formation
of the severe haze occurred and spread over the urban atmosphere in most of the cities of China in the past several years. 相似文献
18.
青岛市汛期降水阶段划分及其环流背景特征 总被引：2，自引：1，他引：1
应用1961年1月到2011年12月的中国722站降水、NCEP/NCAR再分析和青岛市辖7站降水等逐日资料,分析青岛汛期降水阶段及对应的环流气候背景。结果表明:青岛市汛期有5个降水阶段,分别是主汛期开始阶段(6月29日至7月3日),黄淮雨期阶段(7月9—25日),华北雨季阶段(7月27日至8月6日),热带低压阶段(8月11-20日)和主汛期结束阶段(8月29日至9月4日)。其中主雨季(7—8月)呈明显的双峰分布,分别是黄淮雨期阶段和热带低压阶段两个主要降水阶段。副热带高压的季节性移动及其高低空的配置是形成青岛汛期降水阶段的主要成因,各降水阶段对应着相对稳定的天气气候阶段,各降水阶段间的大气环流有明显的突变现象,该研究为细化青岛汛期降水气候预测提供了理论支持。 相似文献