Characteristics of Major PM2.5 Components during Winter in Tianjin, China
Characteristics of Major PM2.5 Components during Winter in Tianjin, China
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DOI：
10.4209/aaqr.2008.11.0054
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发表时间：
2009-03
影响因子：
4
通讯作者：
Weifang Li;Z. Bai;Aixia Liu;Jun Chen;Li Chen
中科院分区：
文献类型：
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作者：
Weifang Li;Z. Bai;Aixia Liu;Jun Chen;Li Chen
2006年12月28日至2007年1月31日，在天津市某城市、工业和沿海站点同时采集细颗粒物，研究每年高污染季节PM2.5主要组分的化学特征。分析了水溶性无机离子、有机碳（OC）和元素碳（EC）。PM2.5的日平均浓度范围为61.5-566.8 μg/m^3，平均值为223.0 μg/m^3。测量到的物种总数约占PM2.5质量的60%，其中有机气溶胶和硫酸盐是两个最大的贡献者。总碳（OC+EC）分别占城市、工业和沿海PM2.5的23.3%、25.5%和19.2%，次级离子物质(SO4（上标2-）、NO3（上标-）和NH4（上标+）分别占27.6%、19.0%和25.9%。工业区PM2.5组成受局地工业排放源的影响。总碳中约80%以OC形式存在，城市、工业和沿海地区OC/EC的平均比值分别为4.5、5.6和4.8。根据最小OC/EC比值估算，次生有机碳（SOC）约占总OC的37.2%~50.3%。发现高Cl（上标-）浓度，平均为9.3 μg/m^3，主要来自人为来源，而不是来自海盐气溶胶。
Fine particles were simultaneously collected at an urban, industrial and coastal site in Tianjin, China from December 28, 2006 to January 31, 2007 to investigate the chemical characteristics of major PM2.5 components during an annually occurring season of high pollution. Water-soluble inorganic ions, organic carbon (OC) and elemental carbon (EC) were analyzed. Daily average concentrations of PM2.5 ranged from 61.5-566.8 μg/m^3 with an average of 223.0 μg/m^3. The sum of the measured species accounted for about 60% of the PM2.5 mass with organic aerosols and sulfates being the two largest contributors. Total carbon (OC+EC) constituted 23.3%, 25.5% and 19.2%, and secondary ionic species (SO4(superscript 2-), NO3(superscript -) and NH4(superscript +)) constituted 27.6%, 19.0% and 25.9% of PM2.5 at the urban, industrial and coastal sites, respectively. The PM2.5 composition in the industrial area was influenced by local industrial emission sources. About 80% of the total carbon existed in the form of OC, and the average OC/EC ratios were 4.5, 5.6 and 4.8 at the urban, industrial and coastal sites, respectively. Secondary organic carbon (SOC), estimated by the minimum OC/EC ratio, accounted for about 37.2%~50.3% of total OC. High Cl(superscript -) concentrations averaging 9.3 μg/m^3 were found, which mostly originated from anthropogenic sources, rather than from sea-salt aerosols.