基于颗粒物化学组分粒径分布特征的源解析方法构建与评估

大气颗粒物污染来源解析可以为大气污染防控提供科学支撑.大部分颗粒物源解析研究是以化学组分为基础,此外,粒径特征也是颗粒物的重要属性之一,通过分析化学组分的粒径特征,有助于提高解析结果准确性.针对目前组分粒径分布信息利用不充分的问题,在三维多粒径因子分析模型(ABB)基础上,将已知源类标识组分粒径分布信息作为约束限制,构建基于组分粒径分布特征的多粒径源解析模型(SDABB).通过模拟数据集对模型进行了评估,探究了SDABB模型对源谱共线性和源贡献粒径分布相似性的敏感程度.结果表明,ABB模型对源谱共线性和源贡献粒径分布相似性较敏感,将粒径分布规律纳入后的SDABB模型,两种情景效果均明显变优,即SDABB模型可以较好解析共线性源类,并且对贡献粒径分布相似性不敏感.     

青海湖湖水性质、颗粒物沉积通量季节和年际变化——来自沉积物捕获器的研究

本文通过在青海湖南盆沉积中心试验性放置的Mark 8-13型时间序列沉积物捕获器所收集到的为期15个月的自然沉降颗粒物,分析了颗粒物沉积通量和物质组成,结合温盐传感器（CTD）所记录湖水参数数据的分析,讨论了青海湖上部10 m左右湖水中所发生沉积作用的季节与年际变化特征及其与环境参数的相互关系。结果表明,采集期间所沉降的总颗粒物具有显著季节和年际变化特征,其平均年沉降通量为112 g·m^-2·yr^-1,其组成主要是自生碳酸盐（高Mg方解石、文石）、生物壳体（介形虫、硅藻等）等内生作用形成的物质,以及少量的碎屑矿物。与实时监测的湖水参数比较表明,具有显著季节和年际变化的青海湖内生物质通量变化主要受控于夏季温度的变化。其沉积机制为：湖水温度的升高,有利于高Mg方解石和文石等自生矿物从碳酸盐过饱和的碱性湖水中结晶沉淀（盐度降低）,也有利于藻类和介形虫等微体生物大量繁殖,表现为温度偏高的2010年比2011年具有较低的湖水盐度和高得多的沉积通量。因此,青海湖自生碳酸盐沉淀通量可以用来反映湖水盐度和/或温度的变化,尽管这些内生作用形成的物质可能只约占到湖底沉积物的5%~20%。为更全面地了解青海湖现代沉积过程,有必要在更多点位、不同的深度进行长期放置捕获器和实时监测湖水参数变化。     

基于多通道分布式VOCs在线监测质谱系统精准识别企业污染源

建立一套适用于工业园区VOCs无组织排放的监管溯源系统,该系统通过多通道分布式质谱在企业内部和厂界进行多个在线监测点位连续监测,实现对VOCs的无组织排放污染源的初步识别.监测数据结合正交矩阵因子分解(PMF)模型和二元条件概率函数(CBPF)方法精准识别园区内不同范围尺度的污染源.该系统成功应用于台州市化工园区内某医...     

北京APEC期间不同颗粒物源解析方法的结果比较

2014年10月8日~11月25日,在北京城市点位采用颗粒物多组分在线监测技术与单颗粒气溶胶质谱（SPAMS）两种方法测定颗粒物化学组分.基于颗粒物在线多组分监测技术得到的受体数据,采用ME2模型进行解析（OC-ME2）;基于SPAMS的观测数据,采用ART-2a和ME2两种方法进行来源解析.SPAMS-ART2a方法解析得到6种颗粒物污染源,而SPAMS-ME2和OC-ME2均确定了5种来源.每种方法都识别出了扬尘源、机动车尾气、燃煤源、工艺过程源和二次源.结果表明：3种方法的解析结果均显示机动车尾气（25.43%~28.84%）和二次源（22.55%~33.50%）是颗粒物的主要来源,其次是燃煤源（20.16%~21.21%）和工艺过程源（12.01%~15.17%）;不同方法解析出的同种源在对颗粒物（PM）的分担率与贡献时间变化上存在较大的差异,这可能与采样方法、化学分析方法和数据分析方法等有关.对APEC会议期间主要污染源类特征进行研究,3种方法解析结果中的首要污染源均是机动车尾气（29.17%~44.18%）,其贡献均高于非会议期间（23.59%~28.79%）,表明在此期间机动车尾气对颗粒物的产生具有重要影响.     

多环芳烃类有机物在腐殖酸上的吸附行为研究

利用CPMAS13CNMR与元素分析相结合的方法测定了3种固体腐殖酸颗粒的化学组成,利用1H-NMR测定了3种腐殖酸溶解部分的化学性质,研究了不同接触时间3种腐殖酸颗粒吸附3种典型多环芳烃类有机物(PAHs)——萘、菲、芘的环境行为.实验结果发现,在吸附的不同阶段,3种腐殖酸吸附PAHs的规律和模式有很大差别:开始阶段,分配作用可能是吸附的主要模式,吸附参数与腐殖酸溶解部分化学性质有一定的相关性;随着接触时间的延长,吸附参数发生突跃性变化,意味着吸附模式发生了转变,此时固体腐殖酸化学组成可能是影响吸附的主要因素.     

PFU微型生物群落监测中异养性指数的应用研究及其分形分析

对常德和汉江的异养性指数(HI)进行了分形分析,表明异养性指数在二维空间分布具有自相似性.异养性指数数据点与化学综合污染指数(P)数据点在双对数坐标中分段拟合时,当常德和汉江的LogP分别小于0 602和0 493时,常德和汉江的分形维数分别为0 39332和0 74110;当常德和汉江的LogP大于0 602和0 493时,常德和汉江的分形维数分别为0 30678和0 27239.拐点的出现表明异养性指数的变化在两个尺度域内遵从着不同的规律.拐点尺度以前,分维数较高,表明群落组成复杂,群落所受污染压迫较小.拐点以后,分维数较低,表明群落组成逐渐简单,群落所受的污染压迫较大.因此对异养性指数的分形研究,可以较好的反映微型生物群落在受到不同的污染压迫时,群落组成从复杂到简单演替过程中的动力学过程.另外,在水质微型生物群落监测方法(PFU)的4个生物参数中,除异养性指数外,其它3个参数都要求有原生动物分类基础,在显微镜下用活体鉴定种类,要求仔细观察,不能遗漏种类,对分析人员的技能要求高.但异养性指数(HI)靠仪器测定,易于掌握.     

Characteristics of airborne particles inside southern California museums

The concentrations and chemical composition of suspended particulate matter were measured in both the fine and total size modes inside and outside five southern California museums over summer and winter periods. The seasonally averaged indoor/outdoor ratios for particulate matter mass concentrations ranged from 0.16 to 0.96 for fine particles and from 0.06 to 0.53 for coarse particles, with the lower values observed for buildings with sophisticated ventilation systems which include filters for particulate matter removal. Museums with deliberate particle filtration systems showed indoor fine particle concentrations generally averaging less than 10 μg m⁻³. One museum with no environmental control system showed indoor fine particle concentrations averaging nearly 60 μg m⁻³ in winter and coarse particle concentrations in the 30–40 μg m⁻³ range. Analyses of indoor vs outdoor concentrations of major chemical species indicated that indoor sources of organic matter may exist at all sites, but that none of the other measured species appear to have major indoor sources at the museums studied. Significant fractions of the dark-colored fine elemental (black) carbon and soil dust particles present in outdoor air are able to penetrate to the indoor atmosphere of the museums studied, and may constitute a soiling hazard to works of art displayed in museums.     

Vertical fluxes of volatile mercury over soil surfaces in Guizhou Province, China

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Effects of geographical dispersion on wind turbine performance in England: A simulation

Hourly wind speed data for a 3-year period, an eight-winer period and eight peak demand times were analyzed from four widely-dispersed sites in England: Dungeness, Fleetwood, Lynemouth and St Mawgan. The data were extrapolated from anomometer heights to the hub height of a 330 kW turbine (25 m) and a 1 MW turbine (45 m) using the method of wieringa (1986, Q. Jl R. met. Soc.112, 867–889). The hub-height wind speeds were passed through the turbine characteristic of the appropriate machine to simulate output time series.These time series were analyzed according to, first, the output in terms of load factors and turbine running times, and, second, the hour-to-hour variability in output levels. The data were analysed for single sites and for sites in combination, to investigate the effects of dispersion. Output at Dungenes and St Mawgan was strongly influenced by the frequency of weather patterns involving pronounced westerly flow over the U.K. In winter, Lynemouth output demonstrated the influence of this circulation type, suggesting that the possibilities for spatial compensation in this season may be few. However, over the year as a whole Lynemouth potential output was not strongly related to the frequency of westerly events, so that outside the winter season compensation for fluctuations in output could be achieved by geographical dispersion of turbine sites. Hour-to-hour variability in potential output was reduced by combination of sites. In the investigation of peak demand times it was shown that some output from wind turbines can be expected.     

火工品温湿度加速老化模型和算法研究

目的 研究对火工品适用的温湿度加速模型,以及加速系数计算程序,获取准确的温湿度加速系数外推公式.方法 通过分析国内外使用的各种双因素加速模型的适用性,确定火工品适用的温湿度加速模型,采用免费自由的开源统计分析软件——R软件,对通过加速试验获取的某点火头2种温湿度加速条件下的试验数据,进行单组数据拟合和多组数据拟合两种温湿度加速老化算法的开发,并且对2种算法、3种寿命分布下寿命外推的准确性进行对比分析.结果 确定了Peck模型适合用于火工品的温湿度加速模型,获取了某电点火头对应的温湿度加速系数和湿度项反应速率常数.结论 基于多组数据拟合的温湿度加速老化算法,比基于单组数据拟合的温湿度加速老化算法对试验数据的兼容性好.3种寿命分布中,Weibull分布的加速系数计算结果最保守.     

滦河流域上游地区主要河流水污染特征及评价

在水资源管理与污染控制的研究过程中,进行水质特征分析与评价具有重要意义.本研究选取滦河流域上游地区29个监测站点,在2010年对河流溶解氧、氨氮、高锰酸盐指数等14项指标进行监测,并分别采用了单因子评价法、综合污染指数法、分级评价法、内梅罗污染指数法、模糊综合评价法及水质标识指数法6种方法对该地区主要河流水污染特征进行分析及评价.结果表明,水质标识指数法比较适于滦河流域上游地区河流的评价.单因子水质标识指数显示,该地区的主要污染物为总氮、氨氮、总磷和高锰酸盐指数,基本呈现富营养化状态;29个站点中小东区水质最差,达到劣Ⅴ类水质,且出现黑臭现象;波罗诺、窑沟门、下板城和平泉4个站点水质最好,均达到Ⅰ类标准;在河流总体评价中,柳河污染最为严重.根据评价结果将所有监测站点分为达标和未达标两类,并应用主成分分析和多元线性回归进行分析,结果表明达标站点和未达标站点的污染物的最大贡献者分别是生活污水和工业废水.研究结果对指导滦河流域水污染防治及水资源管理具有重要意义.     

运用相对组成探针技术研究青藏高原POPs大气传输与来源

为探讨青藏高原大气POPs(持久性有机污染物)空间分布趋势、来源和传输特征,应用POPs相对组成探针技术对16个大气被动采样观测点的数据进行分析,将青藏高原空间尺度上的采样点聚为不同的组,以探讨污染物来源及大气传输过程. 结果表明:青藏高原大气中的HCB(六氯苯)主要来自于本地燃烧,其中人类活动较为频繁的城镇(波密、格尔木、玉树、拉萨、工布江达、拉孜、那曲)具有较高的HCB相对组成(25%～74%). 青藏高原南缘(包括珠峰、然乌、萨嘎)以南亚正在使用的农药——HCHs(六六六)和α-Endo(硫丹)为特征(二者的相对组成之和超过了40%),凸显了南亚污染排放经长距离传输对青藏高原的影响. 剔除HCB影响后,青藏高原中部、东南部河谷地区(鲁朗、拉孜、拉萨、日喀则、工布江达、昌都)及那曲、狮泉河因具有较高的o,p'-DDT相对组成而聚为一组,平均值为40%,表明这些采样点可能受到本地污染排放的影响.      

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.     

场地地下水1,2-二氯乙烷污染的修复实验与数值模拟研究

为筛选适宜的地下水中1,2-DCA(1,2-二氯乙烷)污染的修复方法,本文开展原位修复包括化学氧化清除技术、监测自然衰减技术及其集成技术的有效性研究.首先通过室内实验,研究高铁酸钾和过氧化氢这两种不同氧化剂对1,2-DCA化学清除的效率以及清除过程中对地下水化学环境的影响.结果表明,高铁酸钾和过氧化氢均能有效的进行化学...     

Properties of agricultural aerosol released during wheat harvest threshing, plowing and sowing

This study shows for the first time a chemical and morphological characterization of agricultural aerosols released during three important agricultural operations： threshing, plowing and sowing. The field campaigns were carried out in the eastern part of the Po Valley, Italy, in summer and autumn 2009. The aerosol particles were sampled on quartz fiber filters and polytetrafluoroethylene membranes in order to allow Inductively Coupled Plasma Mass Spectrometry （ICP-MS） analysis and Scanning Electron Microscopy equipped with an Energy Dispersive X-ray Spectrometer （SEM-EDS） investigations, respectively. The organic carbon mass concentrations were measured with a Sunset Laboratory Dual-Optical Organic Carbone/Elemental Carbon （OCEC） Aerosol analyzer. The morphological and chemical analyses by SEM-EDS allowed recognizing four main particle classes： organic, silica, calcite and clay minerals. The organic particles contribute to both fine and coarse aerosol fractions up to ca. 50% for all three agricultural activities. This was also confirmed by OCEC analysis for fine fraction. Most of the agricultural aerosols, about 60%, were single particles and the remaining 40% were agglomerations of particles. The ICP-MS results showed that threshing and plowing produce more aerosol particles than sowing, which was characterized by important amounts of clay minerals produced from land soils.     

大气颗粒物吸湿性研究

大气颗粒物吸湿性是反映颗粒物理化性质的重要指标,吸湿性研究对深入了解颗粒物的环境和健康效应具有重要意义. 总结了国外近年来大气颗粒物吸湿性研究进展:①典型的大气颗粒物吸湿性分析方法为H-TDMA(吸湿性串联差分电迁移率粒径分析仪)系统及其优化方法. ②大气颗粒物吸湿性呈单峰、双峰甚至多峰分布;根据G_f(吸湿性生长因子)随粒径变化的模式,可将大气颗粒物分为强吸湿性和弱吸湿性2类,也可分为纯不溶性、混合不溶性、混合可溶性和纯可溶性4类. ③城市背景点颗粒物的G_f比城市观测点高;城市观测点的颗粒物G_f分布呈夏季高、冬季低,白天高、晚上低的特征. ④颗粒物吸湿性与其化学组成和形态密切相关,纯可溶性盐颗粒物的G_f通常较高. ⑤柴油燃烧源新排放的颗粒物属于弱吸湿性颗粒物,G_f非常小,但在其表面老化后或随燃料中硫含量的增加G_f会明显变大. ⑥生物质燃烧排放颗粒物的G_f相对较高,但存在区域差异性. 针对国内大气颗粒物吸湿性研究现状,提出了未来重点研究方向.      

Source apportionment of PM2.5 light extinction in an urban atmosphere in China

Haze in China is primarily caused by high pollution of atmospheric fine particulates (PM_2.5). However, the detailed source structures of PM_2.5 light extinction have not been well established, especially for the roles of various organic aerosols, which makes haze management lack specified targets. This study obtained the mass concentrations of the chemical compositions and the light extinction coefficients of fine particles in the winter in Dongguan, Guangdong Province, using high time resolution aerosol observation instruments. We combined the positive matrix factor (PMF) analysis model of organic aerosols and the multiple linear regression method to establish a quantitative relationship model between the main chemical components, in particular the different sources of organic aerosols and the extinction coefficients of fine particles with a high goodness of fit (R² = 0.953). The results show that the contribution rates of ammonium sulphate, ammonium nitrate, biomass burning organic aerosol (BBOA), secondary organic aerosol (SOA) and black carbon (BC) were 48.1%, 20.7%, 15.0%, 10.6%, and 5.6%, respectively. It can be seen that the contribution of the secondary aerosols is much higher than that of the primary aerosols (79.4% versus 20.6%) and are a major factor in the visibility decline. BBOA is found to have a high visibility destroying potential, with a high mass extinction coefficient, and was the largest contributor during some high pollution periods. A more detailed analysis indicates that the contribution of the enhanced absorption caused by BC mixing state was approximately 37.7% of the total particle absorption and should not be neglected.     

冬季德州市大气颗粒物消光与化学组成关系研究

为了深入探究华北地区冬季大气颗粒物的消光特性和化学组分之间的关系,本研究于2017年11月—2018年1月在山东省德州市平原县对大气颗粒物消光和化学组成进行了连续在线观测.运用多元线性回归方法和MIE散射模型定量分析了颗粒物各化学组成对颗粒物消光的贡献,进一步地,利用高分辨飞行时间气溶胶质谱(HR-ToF-AMS)结合正矩阵因子解析模型(PMF)得出二次气溶胶(OOA)、生物质燃烧有机气溶胶(BBOA)、还原性气溶胶(HOA)、燃煤燃烧排放的有机气溶胶(CCOA)的浓度,并进一步结合线性回归模型得到OOA、BBOA、HOA、CCOA对消光的贡献.结果显示元素碳(EC)是颗粒物吸光的最主要贡献者, OOA、BBOA和CCOA对颗粒物吸光也具有一定贡献,这主要是由于二次生成和一次排放的棕色碳的吸光造成的.颗粒物各组分与散射关系的分析结果表明,有机物对颗粒物散射影响最大,其中OOA的散射截面最大,对颗粒物散射的贡献也最高,可以占到总散射的53.4%.颗粒物中有机物对大气总消光的贡献可达75.5%,其中OOA、BBOA、CCOA和HOA对总消光的贡献分别为47.8%、14.7%、9.0%、4.0%. Mie散射的结果与多元回归结果比较一致,但部分时间段偏差较大,因此在不同的研究中应根据不同情况选择研究方法.     

The distribution of ammonium salts among a size and composition dispersed aerosol

The chemical and physical processes that govern the distribution of ammonium salt condensate over a size- and composition-dispersed aerosol particle population are considered. From an analysis of the concentration profiles of ammonia, nitric acid, and hydrochloric acid vapors surrounding an aerosol particle, the single particle fluxes of these species are derived. By evaluating the time scales for equilibration of the vapor-phase species with a population of aerosol particles, it is found that ammonium salts in the gas and aerosol phases are not always in equilibrium, especially under less polluted and cooler conditions. The principles that govern the distribution of ammonium salts on aerosol particles of different size and composition are identified, and it is found that thermodynamic equilibrium often does not uniquely determine the distribution of ammonium salt condensate. Thus it is concluded that both transport and thermodynamic properties of the aerosol population govern the distribution of ammonium salt condensate.     

激光法与传统方法比较测定土壤粒度分布的研究

激光法测定土壤粒度是近年来应用的新方法,它的特点是测定速度快、效率高,比传统的经典测定法省时省力省试剂消耗,实验室对环境的二次污染也小,特别是在处理和测定大量样品时,它的优势更为明显。本文作者选择内蒙古地区有代表性的暗棕壤、草甸土、黑土、黑钙土、栗钙土、棕钙土和风沙土7种土壤类型共42个土壤样本为例,采用激光法与传统比重计法对土壤粒度分布测定进行了方法比对研究,设计了激光法三个参数三个水平的正交实验,结果表明粘粒含量激光法测定低于传统方法,粉粒含量则相反,砂粒含量两种方法测定结果最接近;得出了两种方法之间的相关系数和回归方程,P〈0．05时,最大相关系数是：粘粒含量r=0．5822,粉粒含量r=0．9094,砂粒含量r=0．9152;本研究结果还表明激光法与传统比重计法两种方法确定的质地大致相同,认为虽然土壤的粘粒部分就目前的测定结果来看不适合用激光法测定,但粉粒部分和砂粒部分可以用激光法测定后通过两种方法之间的线性回归方程换算,从而提高测定效率。这一研究结果明确了激光法与传统比重计法测定土壤粒度分布的差异,对使用两种不同方法研究土壤颗粒组成具有借鉴作用,并且在土壤批量样品粒度的分析测定中具有非常实用的推广意义。