北京市典型排放源PM_(2.5)成分谱研究

为了建立和完善北京市PM_(2.5)本地化源谱,对北京市11类排放源PM_(2.5)进行采集,并测定其26种组分,分析了不同排放源源谱的组分特征.结果表明,在有组织排放源中,燃煤电厂PM_(2.5)中OC和Si含量很高,占PM_(2.5)的质量分数分别为8.56%和6.19%(平均值),而供热/工业锅炉排放PM_(2.5)中则是SO_4~(2-)(占48.38%)和OC(11.0%)比例最高,水泥窑炉PM_(2.5)中OC(7.12%)、Ca(4.81)和Si(4.41%)占有较大比例;垃圾焚烧排放的PM_(2.5)中Si、Ca、K和SO_4~(2-)均较高,分别占8.15%、9.36%、7.17%和6.79%,且Cl~-含量(2.5%)高于其他所有源,生物质燃烧源PM_(2.5)中OC(21.7%)、Si(6.75%)、Ca(6.15%)较为丰富,餐饮源PM_(2.5)中OC(19.44%)、SO_4~(2-)(5.76%)和K(3.11%)含量均较高;无组织开放源中,道路扬尘和土壤风沙PM_(2.5)化学组分含量变化较为一致,均是Si(分别为16.8%和9.3%)和OC(分别为8.89%和6.61%)最高,建筑水泥尘PM_(2.5)中Ca(17.46%)含量高于其他源;流动排放源PM_(2.5)中OC、EC比例最高,其中,重型柴油车的OC(29.79%)与EC(26.5%)排放比例相当,而轻型汽油车OC排放占有绝对优势(占75%).本文通过对比国内外部分排放源PM_(2.5)成分谱的差异,指出不同区域相同源类排放的PM_(2.5)化学组分差异较大,在应用受体模型中的化学质量平衡模型(CMB)判断受体颗粒物来源时,应基于本地的排放源成分谱,以避免较大的误差.     

A theoretical comparison between intentional elemental and isotopic atmospheric tracers

A theoretical comparison has been made between intentional elemental and intentional isotopic tracers for the study of the fate of emissions into the atmosphere. The use of an elemental tracer requires a very large signal to background ratio because the latter cannot be determined while the tracer experiment is in progress. It is shown that the variation in the ambient background is the major source of uncertainty for the elemental tracer. The use of a stable isotopic tracer is definitive because the isotopic composition of the background is constant and can be measured in real time during the isotopic analysis of the sample. Simple error analysis suggests that the isotopic tracer is intrinsically definitive and more accurate compared to the elemental tracer. This is because elemental tracers are subject to inherent biases of unknown magnitude that do not exist for isotopic tracers. If it is assumed that the background can vary by a factor of two during a tracer experiment, then for a given confidence in the detection of the tracer signal more than 10⁴ times more elemental tracer is required than isotopic tracer. It is concluded that stable isotopic tracers are inherently superior to elemental tracers; however; this conclusion now needs to be demonstrated in an actual field experiment.     

PM10可替代源成分谱的建立方法及其应用

对收集到的我国35个城市的PM10有效实测源成分谱进行系统聚类,应用系统聚类和方差分析方法,对源成分谱进行聚类和区域的划分.对聚为一类的各城市源成分谱进行主成分分析,所得主成分得分系数作为权重,加权运算建立可替代源成分谱.利用R、CD以及CMB模型解析所得源贡献值的相对误差,评价所建立的可替代源成分谱的合理性及可行性.得到6种污染源的13个可替代源成分谱,煤烟尘与扬尘各三类,土壤风沙尘、钢铁尘与建筑水泥尘各两类,机动车尾气尘一类.煤烟尘与钢铁尘可以直接进行替代;建筑水泥尘不存在明显区域特征;机动车尾气尘由于数据代表性不足,建议采用实测源成分谱;土壤风沙尘与扬尘的替代标准有待进一步的研究.     

Anthropogenic contributions to the carbonaceous content of aerosols over the Pacific Ocean

During a joint U.S./U.S.S.R. research cruise from 3 May to 27 July 1987 both total and fine (< 2 μm) particulate material was sampled. This cruise started in the Hawaiian Islands and then proceeded to the Kamchatka peninsula, south to Wellington, New Zealand, south of Australia into the Indian Ocean, to Singapore and then returned to the Hawaiian Islands by sailing just north of the Equator. Particulate samples, collected on quartz fiber and Teflon filters, were analysed for organic and elemental carbon by transmission thermo-optical carbon analysis and for trace elements by energy dispersive X-ray fluorescence.In the Northern Hemisphere the total particulate, organic carbon and elemental carbon concentration ranges were, respectively, 10–25, 0.5–2.5 and 0–0.3 μg m⁻³. In the Southern Hemisphere they were, respectively, 5–10, <0.6 and <0.02 μg m⁻³. In the Northern Hemisphere the fine particulate concentration range was 2–15 μg m⁻³ and the fine fraction varied from 20 to 80% of total aerosol loading. In the Southern Hemisphere the fine particulate loading was 1.2–1.7 μg m⁻³ and was usually less than 20% of the total particulate mass.Chemical mass balance (CMB) modeling was used to determine possible anthropogenic particulate contributions to the ocean aerosol. Readily available source profiles were used for CMB modeling. Sea-salt aerosol was represented by either the conventional EPA marine source profile or by the average of ambient ocean aerosols sampled in very clean mid-ocean regions. Usually 60–90% of ambient particulate mass was “explained” by the CMB model. Sources such as soil, catalytic auto emissions and wood-burning emissions were found to be possible contributors to the ocean aerosol, especially in the Northern Hemisphere. Anthropogenic contributions were estimated to contribute from 10 to 30% of oceanic aerosol mass. Emissions from a hugh forest fire that burned in northern China during the spring of 1987 were possibly detected, but the CMB model cannot distinguish this source from emissions from heating and cooking with wood.Since anthropogenic emissions are mainly combustion emissions which usually contain a large carbon component, carbon data is essential to CMB modeling. The relatively good CMB results obtained in this study suggest that it might be useful to develop source profiles for major emission sources in those countries which contribute most directly to oceanic aerosols. Perhaps characteristic national or regional source profiles could be developed.     

海口市PM_(2.5)和PM_(10)来源解析

以海口市为例,研究了我国典型热带沿海城市——海口市环境空气颗粒物的污染特征和主要来源.2012年春季和冬季在海口市区4个采样点同步采集了环境空气中PM10和PM2.5样品,同时采集了多种颗粒物源样品,并使用多种仪器分析方法分析了源与受体样品的化学组成,建立了源化学成分谱.使用CMB(化学质量平衡)模型对海口市大气颗粒物进行源解析.结果表明:污染源贡献具有明显的季节特点,并存在一定的空间变化.冬季城市扬尘、机动车尾气尘、二次硫酸盐和煤烟尘是海口市PM10和PM2.5中贡献较大的源,在PM10和PM2.5中贡献率分别为23.6%、16.7%,17.5%、29.8%,13.3%、15.7%和13.0%、15.3%;春季机动车尾气尘、城市扬尘、建筑水泥尘和二次硫酸盐是海口市PM10和PM2.5中贡献较大的源,在PM10和PM2.5中贡献率分别为27.5%、35.0%,20.2%、14.9%,12.8%、6.0%和9.5%、10.5%.冬季较重的颗粒物污染可能来自于华南内陆地区的区域输送,特别是,本地排放极少的煤烟尘和二次硫酸盐受区域输送的影响更为显著.     

Regional apportionment of sulfate and tracer elements in Rhode Island precipitation

Regional receptor modeling methods have been used to estimate the relative contributions of northeastern and midwestern source regions to sulfate wet deposition in southern Rhode Island. Three years' precipitation samples were collected and analyzed for the tracer elements As, Sb, Se, and noncrustal IV, which were used in a ‘chemical element balance’ procedure to determine the relative regional contributions. Careful considerations is given to the possibility of fractionation processes altering the relative proportions of the tracers during precipitation scavenging, with the conclusion that such processes are unlikely. The Midwest is the major source for sulfate in precipitation (75% annually). By contrast, aerosol sulfate is about 50% midwestern, suggesting that distant midwestern sources are more important at cloud level than at the surface. Winter rain is slightly more northeastern than summer rain, while snow is markedly so. Comparison of individual event apportionments with synoptic circulation patterns during those events indicates that the apportionments are reasonable.     

新疆阿克达拉大气背景点气溶胶物质来源研究

文章利用2004年7月~2005年3月间新疆阿克达拉区域大气本底观测站PM10和TSP有机碳、元素碳及水溶性离子的组成数据,分别采用主成分分析法(Principal Component Analysis,PCA)和绝对主成分分析法(Absolutely Principal Component Analysis,APCA)对大气气溶胶物质来源进行研究。结果表明PM10中气溶胶来源及贡献率分别为:人为污染源(49.6%)、地壳矿物质粉尘(17.3%)、盐渍化地壳矿物质粉尘(33.1%);TSP中气溶胶来源及贡献率分别为:盐渍化地壳矿物质粉尘(21.3%)、地壳矿物质粉尘及人为污染混合源(50.8%)、人为污染源(27.8%)。由于阿克达拉大气本底观测站位于我国气候上游,该站PM10和TSP中不同来源物质贡献率的源解析结果对于研究中国西北地区大气背景气溶胶的特性及其气候效应具有重要意义,对我国西北边境大气背景区空气污染治理对策的制定有一定的参考价值。     

The relationship between ozone and regional tracers in rural Rhode Island

Ozone and regional tracers are directly related at a rural Rhode Island site during summer. Unlike elemental tracers and sulfate, ozone has a significant background which appears to be unrelated to regional-pollution sources. Summer ozone concentrations were apportioned among northeastern and midwestern sources using results from regional-scale receptor modeling of pollution aerosol. The Northeast contributed roughly 40% more than the Midwest, but ‘background’ accounted for up to half of the average ozone concentration.     

Building wake dispersion at an Arctic industrial site: Field tracer observations and plume model evaluations

Ten multi-hour atmospheric dispersion SF₆ tracer experiments were conducted during October and November of 1987 near a large oil gathering facility in the Prudhoe Bay, Alaska, oilfield reservation. The purpose of this study was to investigate dispersion under arctic conditions and in situations where building-generated airflow disturbances dominate downwind distributions of ground level pollutant concentrations. This was accomplished with a network of micrometeorological instruments, portable syringe tracer samplers, continuous tracer analyzers, and infrared visualization of near source plume behavior.Atmospheric stability and wind speed profiles at this arctic site are influenced by the smooth (surface roughness = 0.03 cm), snow covered tundra surface which receives negligible levels of solar isolation in winter. The dispersion of pollutants emitted from sources within the oil gathering facility, however, is dominated by the influence of nearby buildings when high winds generate elevated ground level concentrations. An order of magnitude increase in maximum ground level concentration was observed as wind speeds increased from 5 to 8 m s⁻¹ and another order of magnitude increase was observed as winds increased from 8 to 16 m s⁻¹. Variation in maximum concentrations was also observed with changes in wind direction. Vertical plume diffusion (σ_z) near the buildings was a factor of 2–3 greater than that observed in open terrain and was dependent on both wind speed and the projected building width and location of nearby buildings. Wind tunnel tracer distributions for east winds agree with field observations but also indicate that a significant increase in plume downwash occurs with other wind directions. Concentration distributions were calculated using several versions of the Industrial Source Complex (ISC) model. Model estimates of ground level concentrations were within a factor of three depending on wind direction. The model predictions are extremely sensitive to the ratio of plume height to vertical plume diffusion which is significantly influenced by a complex aerodynamic wake in the field.     

Characteristics of air particulate matter and their sources inurban and rural area of Beijing, China

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利用SPAMS研究石家庄市冬季连续灰霾天气的污染特征及成因

2014年11月18~26日石家庄市发生了连续的灰霾天气.利用位于石家庄市大气自动监测站(20 m)的单颗粒气溶胶质谱仪(SPAMS)分析了细颗粒物的化学组成,根据石家庄市大气污染物排放源谱库对主要成分进行了来源解析,并结合颗粒物质量浓度和气象条件研究了该地区冬季灰霾天气成因.结果表明,石家庄市大气细颗粒物来源分为7类,各源示踪离子:燃煤源为Al,工业源为OC、Fe、Pb,机动车尾气源为EC,扬尘源为Al、Ca、Si,生物质燃烧源为K和左旋葡聚糖,纯二次无机源为SO-4、NO-2和NO-3,餐饮源为HOC.灰霾期间大气中主要含有OC、HOC、EC、HEC、ECOC、富钾颗粒、矿物质和重金属等8类颗粒,其中OC和ECOC颗粒最多,分别占到总数的50%和20%以上,OC颗粒主要来自燃煤和工业工艺,ECOC颗粒主要来自燃煤和机动车尾气排放.灰霾发生时含有NH+4、SO-4、NO-2和NO-3等二次离子的颗粒物占比升高,其中含NH+4颗粒增幅最大;EC、OC与NO-3、SO-4、NH+4在灰霾天气下的混合程度均比干净天气高,其中与NH+4的混合程度加剧最为明显.冬季采暖期煤炭的大量燃烧、医化行业工艺过程及机动车尾气等污染源排放的一次气态污染物(SO2、NOx、NH3、VOCs)和一次颗粒物在静稳天气中难以扩散而迅速累积,气态污染物发生二次转化形成硝酸铵、硫酸铵,而颗粒物之间通过碰撞形成二次颗粒物并发生不同程度的混合,从而导致大气能见度下降,以上是石家庄市冬季灰霾形成的主要原因.     

城市间PM2.5源的碳成分谱比较

为了解我国不同城市PM_2.5源的碳成分谱特征和地域差异,采集沈阳市、十堰市和乌鲁木齐市的燃煤源、柴油车尾气源、汽油车尾气源和餐饮源样品,使用热光透射法分析PM_2.5中的总碳（TC）、有机碳（OC）和元素碳（EC）,以及细分的8种碳组分（OC1,OC2,OC3,OC4,EC1,EC2,EC3和OPC_T）,构建各类污染源碳成分谱.结果表明：3个城市4类源TC/PM_2.5从高到低分别为：餐饮源（65.1%±8.4%）、柴油车尾气源（46.2%±9.5%）、汽油车尾气源（37.7%±3.5%）和燃煤源（17.3%±8.0%）;OC/TC在餐饮源中最高（98.0%±0.5%）,EC/TC在柴油车尾气源中最高（38.6%±8.5%）.3个城市同类源的碳组分含量受污染源细分后的不同类型影响有一定差异,但归一化处理后总体仍表现为燃煤源中OC2（14%~30%）和OC3（13%~23%）含量最高,柴油车尾气源中EC2（22%~56%）含量最高,汽油车尾气源中OC2（24%~41%）、OC1（16%~42%）和OC3（12%~26%）含量最高,餐饮源中OC2（21%~43%）和OC3（23%~49%）含量最高.不同污染源的OC/EC值为燃煤源在0.4~7.6之间,柴油车尾气源在0.2~5.6之间,汽油车尾气源在1.1~38.5之间,餐饮源在6.4~170.2之间.分歧系数结果显示3个城市不同源的碳成分谱具有差异性,同类源的碳成分谱具有相似性.将3个城市同类源碳成分谱合并后利用化学质量平衡灵敏度矩阵得到OC2,OC3,OC4,EC1和OPC_T可共同作为燃煤源的标识组分;EC2是柴油车尾气源的标识组分;OC1,OC2和OC3可共同作为汽油车尾气源的标识组分;OC2和OC3可共同作为餐饮源的标识组分.沈阳市、十堰市和乌鲁木齐市相同污染源相似的碳成分谱和一致的标识碳组分可为国内其他城市相关研究提供数据参考.     

Source types in Canadian precipitation chemistry

Precipitation data generated by Canadian Air and Precipitation Monitoring Network (CAPMoN) have been analysed by an iterative multiple linear regression method, revealing five source types or components, each with distinctive seasonal and geographic variations. Each source types has its characteristics chemical profile. The profiles suggest that two of the source types are rural (apparently derived from fertilizer and soil), two are urban/industrial (apparently derived from SO₂ and NO_x emissions), and one is sea salt. The NO_x-derived component is highly acidic, the SO₂-derived component is also very acidic, the fertilizer component is slightly alkaline, and the soil component is more alkaline.Charge balance calculations show a fairly consistent deficit in anions, a deficit which is especially important for the NO_x-derived component. The anion deficit results suggest that more complete chemical analyses are required.The chemical profiles from CAPMoN data have been used to determine the component contributions to precipitation data collected in Manitoba by the provincial Ministry of the Environment. Back trajectories for the Manitoba data show distinct geographic and seasonal effects, including: (i) seasalt input to Manitoba is derived mainly from Hudson Bay and the Arctic, especially in fall and winter; (ii) the SO₂ component has ubiquitous sources, including polar sources: (iii) the fertilizer component arrives mainly form the U.S. rural Midwest, especially in spring and fall; (iv) the soil component has northern sources, with perhaps transpolar and trans-Pacific origins, in spring and summer; and (v) the NO_x component appears to be derived from northern sources at polar sunrise in spring.     

Observation of possible elemental sulfur in the marine atmosphere and speculation on its origin

Samples obtained during research cruises in the North Atlantic and the North Pacific showed possible evidence of gas-phase elemental sulfur, S₈. Though the sampling and analytical method are still untested for this sulfur species, these data represent the first suggestion that this sulfur species exists in the marine troposphere. Concentrations of S₈ were ∼ 1 ng m⁻³ or less, though these measurements may represent a lower limit of the true ambient concentration. Though there are only few data, concentrations of elemental sulfur appear to be elevated near coastal or continental margins in the North Atlantic. Possible sources of elemental sulfur include direct vaporization during the sulfur processing, automotive emissions, geothermal emissions, and heterogeneous oxidation of reduced sulfur in cloud droplets.     

地下水“三氮”污染来源及其识别方法研究进展

地下水"三氮"污染来源的识别研究对污染控制与修复有重要的意义.在阐述地下水"三氮"污染来源(大气氮沉降、土壤天然有机氮矿化、地表径流氮输入、人类活动氮排放等)及其在我国的分布特征的基础上,总结了国际上常用的"三氮"污染来源识别方法,包括水化学方法、统计学相关方法、区域氮平衡法、稳定同位素示踪法及一些新型示踪方法.指出由于"三氮"污染来源的多样性及污染形成机制的复杂性,单一识别方法在应用中均有较明显的局限性,目前主流识别手段为稳定同位素示踪法与多种识别方法相综合.进一步提出要加强新型示踪方法的开拓、定量识别方法的优化,污染源识别与迁移转化机制、地下水补排条件、地下水-地表水转化关系等研究相结合为未来发展的主要趋势.     

中国挥发性有机物（VOCs）排放源成分谱研究进展

我国VOCs排放来源多、排放成分复杂.排放源成分谱是识别VOCs排放源特征的基本信息,对开展我国大气复合污染研究及制定污染控制策略具有重要意义.本文在介绍排放源成分谱的测量方法和总结我国排放源成分谱测量结果的基础上,阐述了典型排放源VOCs成分谱组分特征.不完全燃烧产物(烯烃和醛酮类)是机动车尾气的重要组分,烯烃在我国油品挥发成分谱中的比例较高,含氧VOCs在溶剂使用源和燃烧排放源中不容忽视,化学组分复杂是工业排放的重要特征.文章还指出了源谱研究的不足之处,主要包括源谱采集与测试方法不规范、测量结果质量难以保证及评价、含氧VOCs组分关注不够、工业排放源成分谱缺失等.从源谱的测量方法、测量组分和数据后处理等方面进行规范化,继续加强机动车排放研究,开展石油化工等工业源谱测量,构建我国本地化VOCs源谱数据库将是今后重要研究工作.     

基于PMF和源示踪物比例法的大气羰基化合物来源解析:以南京市观测为例

大气羰基化合物在对流层大气化学中发挥着重要作用,其受到直接排放和二次生成的共同影响,来源研究面临挑战.本研究基于2017年3月在南京市开展的羰基化合物观测,分别利用源示踪物比例法(STR)和正交矩阵因子模型(PMF)对羰基化合物进行来源解析,并将二者结果进行比较,以探讨导致来源解析不确定性的因素.本研究共检测出11种羰...     

Understanding the sources and composition of the incremental excess of fine particles across multiple sampling locations in one air shed

Well-designed health studies and the development of effective regulatory policies need to rely on an understanding of the incremental differences in particulate matter concentrations and their sources. Although only a limited number of studies have been conducted to examine spatial differences in sources to particulate matter within an air shed, routine monitoring data can be used to better understand these differences. Measurements from the US EPA Chemical Speciation Network （CSN） collected between 2002-2008 were analyzed to demonstrate the utility of regulatory data across three sites located within 100 km of each other. Trends in concentrations, source contribution, and incremental excesses across three sites were investigated using the Positive Matrix Factorization model. Similar yearly trends in chemical composition were observed across all sites, however, excesses of organic matter and elemental carbon were observed in the urban center that originated from local emissions of mobile sources and biomass buming. Secondary sulfate and secondary nitrate constituted over half of the PM2.5 with no spatial differences observed across sites. For these components, the excess of emissions from industrial sources could be directly quantified. This study demonstrates that CSN data from multiple sites can be successfully used to derive consistent source profiles and source contributions for regional pollution, and that CSN data can be used to quantify incremental differences in source contributions of across these sites. The analysis strategy can be used in other regions of the world to take advantage of existing ambient particulate matter monitoring data to better the understanding of spatial differences in source contributions within a given air shed.     

紫色土旱坡地氮流失通量对减肥配施秸秆的响应

紫色土旱坡地被认为是三峡库区泥沙和面源污染的主要来源地,加强对紫色土旱坡地壤中流和地表径流中氮流失特征的研究,对防控三峡库区的面源污染有重要的现实意义.依托中科院成都山地所忠县石宝寨试验站的紫色土旱坡地定位径流小区,设置不施肥(CK)、常规施肥(T₁)、优化施肥(T₂)和减肥配施秸秆(T₃)这4种不同的处理,通过监测在油菜-玉米轮作制度下紫色土旱坡地壤中流和地表径流的流失通量、各次径流不同氮形态的流失浓度和流失通量,研究紫色土旱坡地氮流失通量对减肥配施秸秆的响应.结果表明,壤中流径流量占总径流量的比例达到60.14%～88.56%,壤中流氮流失通量占全氮流失通量的72.88%～92.35%.铵态氮主要通过地表径流的方式流失,硝态氮主要通过壤中流的方式流失且是氮流失的主要形态.不同处理的铵态氮和硝态氮流失通量均呈现出T₁>T₂>T₃>CK,T₃处理的氮流失通量为20.07 kg·(hm²·a)     

基于多种新型受体模型的PM2.5来源解析对比

为了解多种新型受体模型的适用性,利用正定矩阵分解/多元线性引擎2-物种比值（PMF/ME2-SR）、偏目标转换-正定矩阵分解（PTT-PMF）、正定矩阵分解（PMF）和化学质量平衡（CMB）这4种受体模型对我国北方典型城市细颗粒物(PM_2.5)数据进行同步解析并互相验证.结果发现,燃煤源（25%～26%）、扬尘源（19%～21%）、二次硝酸盐（17%～19%）、二次硫酸盐（16%）、机动车源（13%～15%）、生物质燃烧源（4%～7%）和钢铁源（1%～2%）这7种主要污染源对研究地区PM_2.5有贡献.通过比较不同模型获得的源成分谱和源贡献以及计算各源的差异系数（CD）和平均绝对误差（AAE）,发现4种模型的解析结果具有较高的一致性（平均CD值在0.6～0.7之间）,但不同模型对各污染源中组分的识别存在差异.相比于传统PMF模型,PMF/ME2-SR模型由于纳入一次源类的特征比值,能够更好地区分源谱特征较为相似的源类,如扬尘源的CD和AAE分别比PMF模型低15%和54%; PTT-PMF模型以实测一次源谱和虚拟二次源谱为约束目标,计算的二次硫...