Ozone and secondary organic aerosol formation potential from anthropogenic volatile organic compounds emissions in China

Volatile organic compounds (VOCs) are major precursors for ozone and secondary organic aerosol (SOA), both of which greatly harm human health and significantly affect the Earth''s climate. We simultaneously estimated ozone and SOA formation from anthropogenic VOCs emissions in China by employing photochemical ozone creation potential (POCP) values and SOA yields. We gave special attention to large molecular species and adopted the SOA yield curves from latest smog chamber experiments. The estimation shows that alkylbenzenes are greatest contributors to both ozone and SOA formation (36.0% and 51.6%, respectively), while toluene and xylenes are largest contributing individual VOCs. Industry solvent use, industry process and domestic combustion are three sectors with the largest contributions to both ozone (24.7%, 23.0% and 17.8%, respectively) and SOA (22.9%, 34.6% and 19.6%, respectively) formation. In terms of the formation potential per unit VOCs emission, ozone is sensitive to open biomass burning, transportation, and domestic solvent use, and SOA is sensitive to industry process, domestic solvent use, and domestic combustion. Biomass stoves, paint application in industrial protection and buildings, adhesives application are key individual sources to ozone and SOA formation, whether measured by total contribution or contribution per unit VOCs emission. The results imply that current VOCs control policies should be extended to cover most important industrial sources, and the control measures for biomass stoves should be tightened. Finally, discrepant VOCs control policies should be implemented in different regions based on their ozone/aerosol concentration levels and dominant emission sources for ozone and SOA formation potential.     

2008～2018年武汉市BC气溶胶时间演变特征及其来源分析

黑碳(BC)作为最重要的吸收性气溶胶,其辐射强迫显著地改变大气边界层结构和近地面大气污染物的累积。基于2008～2018年武汉市BC和气象要素的观测数据,结合CWT潜在来源模型,分析了BC的时间演变特征和潜在来源分布。结果表明武汉BC平均质量浓度为6 926.4±4 090.6 ng/m³,?ngstr9m指数(AAE)和液体燃料源对BC贡献占比(P)的平均值分别为0.98±0.44和76.6%,BC主要来自液体燃料的燃烧。2014～2017年BC质量浓度呈现显著的下降趋势,液体燃料对BC的贡献逐年增加。BC的季节分布为冬季(8 537.3 ng/m³)>春季(7 513.2 ng/m³)>秋季(6 820.2 ng/m³)>夏季(6 161.9 ng/m³),BC_liquid占比为秋季(80.0%)>冬季(77.3%)>春季(76.2%)>夏季(72.9%)。不同季节BC日变化特征不同。四个季节BC日变化在2008～2...     

黑碳气溶胶研究现状

简单介绍了黑碳气溶胶的来源、生成机理、一般性质及危害,概括介绍了国内外相关领域的研究现状,指出黑碳气溶胶在气候变化以及大气环境等领域中具有重大的研究价值和意义.     

白令海峡及其附近海域气溶胶中金属元素含量特征

北极考察沿线气溶胶中金属元素质量浓度随纬度变化,其分别受到来自中国大陆粉尘及中国、日本、韩国、俄罗斯以及北美地区工业排放气溶胶的不同程度的影响.富集因子的计算结果表明,楚科奇海、日本海和白令海等海域元素的富集因子很接近. Fe,Co,Ni,As,Sb,W,Mo ,Mn和Ca与地表的风化关系密切,为地壳源元素;Ca,Mg总体为海洋源元素,主要来自海洋;Pb,Zn,Cd,V 和Cr相对地壳和海洋均为富集元素,主要可能来自矿产冶炼、工业排放、燃煤和燃油等人为污染源.北极楚科奇海、白令海、日本海、西太平洋、东印度洋、南大洋及我国中山站邻近海域海洋气溶胶中的微量重金属质量浓度均值对比表明,西太平洋气溶胶中的各种金属元素的平均质量浓度均远远高于其他地区.总体上看,北半球气溶胶受陆源性物质和人为污染源影响比南半球严重,其中楚科奇海较日本海和白令海严重,南半球气溶胶质量浓度则依纬度的升高而逐渐降低.气溶胶月总沉降通量具有明显的区域性,其大小排序为:西太平洋>楚科奇海>白令海和日本海>东印度洋>南大洋>中山站邻近海域.      

珠三角地区不同季节颗粒物数谱分布特性

基于珠三角大气超级站不同季节3 nm~10μm颗粒物数谱分布在线监测数据,系统分析不同季节颗粒物数浓度、表面积浓度与体积浓度的水平与构成及数谱分布日变化规律,揭示了珠三角地区颗粒物数谱分布特征。结果表明,冬季、春季和秋季珠三角大气超级站总颗粒物数浓度分别为2.17×104、1.97×104、2.24×104个/立方厘米,总颗粒物表面积浓度分别为2.98×103、2.28×103、2.78×103μm2/cm3,总颗粒物体积浓度分别为1.33×102、1.04×102、1.40×102μm3/cm3。颗粒物总数浓度中,爱根核模和积聚模态颗粒物是主要贡献者,在总数浓度的比例均达到40%以上;总颗粒物表面积浓度中,积聚模态颗粒物是主要贡献者,月平均比例高达88%以上;总颗粒物体积浓度中,积聚模态颗粒物也是主要贡献者,月平均贡献为65%~80%,其次为粗粒子模贡献较大,比例为20%~30%。积聚模态颗粒物的重要贡献较好地体现了超级站的区域性。冬季、春季和秋季颗粒物数浓度平均日变化趋势均为7:00~9:00和18:00~20:00存在较高的爱根核模态颗粒物数浓度,意味着机动车排放对细颗粒物污染的影响较显著。10月颗粒物数谱分布平均日变化中存在明显的颗粒物增长过程,体现了新粒子生成事件的重要影响。     

武汉地区沙尘天气气溶胶粒径分布特性研究

通过利用湖北省大气复合污染自动监控预警中心的振荡天平法颗粒物监测仪、光散射法气溶胶粒径谱仪,对武汉地区一次典型沙尘天气过程中记录的不同粒径气溶胶颗粒数量浓度、相对质量浓度进行研究。结果表明,在武汉地区沙尘天气过程中,粗颗粒显著增多,而细颗粒显著减少,这与部分研究发现的沙尘天气过程中粗颗粒与细颗粒共同显著增多的结论有所不同。粒径谱仪分析显示,大于PM5颗粒的增多对粗颗粒浓度增加有显著贡献,而小于PM0.5颗粒的减少则对细颗粒浓度降低有主要贡献,这可能是武汉地区沙尘天气过程颗粒物的变化特点。     

茂名市大气PM_(2.5)在线源解析

于2014年12月31日—2015年1月12日,利用单颗粒气溶胶质谱仪对茂名市大气中PM2.5进行在线监测和分析。结果表明,茂名市大气颗粒物污染来源分布(颗粒数占比)分别为扬尘6%、工业工艺源10.9%、生物质燃烧14.7%、机动车尾气27.5%、燃煤23.4%、二次无机源7.7%和其他9.9%。空气质量从重度污染转为优良天气过程中,机动车尾气的贡献率基本保持在20%以上,而燃煤占比从28.9%降至12.3%;空气质量从优良转为污染天气的过程中,工业工艺源、二次无机源、生物质燃烧、燃煤的占比增加,而机动车尾气占比不断下降。     

Using Archive Data to Investigate Trends in the Sources and Composition of Urban PM10 Particulate Matter: Application to Edinburgh (U.K.) Between 1992 and 1997

By extending the method of Stedman (1998), daily dataof atmospheric concentrations of gravimetricPM₁₀, black smoke (BS) and sulphate aerosol (SA)from national networks were analysed to determine thetrends in time of the contribution of different sources of particulate matter to total PM₁₀ measured in central Edinburgh. Since BS is an indicator of combustion-related primary sources of particulate matter, the quantity obtained by subtraction of daily BS from daily PM₁₀ is indicative of the contribution to total PM₁₀ from other primary sources and from secondary aerosol. This PM₁₀-BS statistic was regressed on SA, since SA is an indicator of variation in secondary aerosol source. For Edinburgh, SA is a considerably better indicator of PM₁₀-BS during summer than winter (reflecting the much greater photochemical generation of secondary aerosol in summer) and there is evidence that the contribution of other secondary aerosol (presumably nitrate aerosol) has increased relative to SA between 1992 and 1997. The concentration of non-combustion primary particulate material (marine aerosol, suspended dust) to PM₁₀ in Edinburgh has not changed over this period but is about twice that calculated as the U.K. national average. The increasing input to PM₁₀ from secondary aerosol sources at regional rather than urban scale has important implications for ensuring local air quality compliance. The method should have general applicability to other locations.     

气溶胶与降尘中多环芳烃的含量分布研究

通过广东省茂名市区四个不同功能点大气气溶胶和降尘中多环芳烃的含量分布研究发现 :1、气溶胶中优控多环芳烃大大高于降尘中的含量 ,为降尘的 5.97～ 1 9.3倍 ;以石化厂区为例 ,非优控多环芳烃在气溶胶中的相对含量更高 ,为降尘的 2 4 .7倍。2、气溶胶中优控多环芳烃和非优控多环芳烃的分布为随分子量增加而含量增高的趋势 ,但降尘中优控多环芳烃的高含量相对集中于萤蒽至苯并 (b)萤蒽之间。3、不同功能区由于排放源的差别所表现出的气溶胶和降尘中优控多环芳烃总量及总量比值、部分强致癌和致癌物含量及含量比值均存在差异。4、对气溶胶和降尘中多环芳烃研究可以对降尘中非优控多环芳烃降解和溶解量进行估算。以石化厂区为例 ,降尘中非优控多环芳烃比原始含量已减少76%。     

大气气溶胶地基光学遥感物联网系统研究

研究了大气气溶胶地基光学遥感物联网系统的设计问题.根据其应用特点从传感层、传输层、数据层、应用层这几个组成部分对系统进行了设计,并初步实现.测试表明:设计的大气气溶胶地基光学遥感物联网系统具有支持数据实时共享、无人值守运行、快速数据融合、环境参数在线显示、历史数据快速查询和分析、仪器远程管理维护等优点,可实现大气气溶胶特性的网络化和自动化观测,对研究气溶胶对环境和气候的影响具有重要应用价值.