济南市大气细颗粒物中的碳组分特征

The Characteristics of Carbon Components in Atmospheric Fine Particulate Matter of Jinan City

大气颗粒物作为济南市大气环境的首要污染物,严重影响了济南市环境空气质量.通过对济南市大气细颗粒物的滤膜采样与碳组分分析,对济南市细颗粒物中的碳质组分进行了研究,结果表明,OC、EC的平均质量浓度为12.1、4.8μg/m^3,占PM_(2.5)质量的12.0%和4.8%.OC为PM_(2.5)中的优势碳组分,春、夏、秋季的含量均在10%以上;春、夏、秋季TC对PM_(2.5)的贡献均达到了15%以上.济南春、夏、秋季PM_(2.5)中OC/EC比值分别为2.4、2.4、2.7,均大于2,说明济南春、夏、秋季都存在不同程度的二次有机污染.济南市春、夏、秋季有机碳中SOC的贡献率分别为14.8%、56.9%、49.6%.夏、秋季气温高,日照时间长的气象条件促进了SOC的形成.SOC质量浓度为4.8μg/m^3,总有机碳中SOC的贡献为40.4%,表明SOC已经成为济南市细颗粒物中的重要贡献源.通过对8个碳组分在PM_(2.5)中的含量分析发现,该采样点春、夏、秋季碳组分组成相似,特征组分均为EC1,说明汽油车尾气是济南市主要的污染源.

As the primary pollutant for atmosphere in the city of Jinan, particulate matter （PM） has seriously impacted on the air quality of Jinan. This paper is based on the filter sampling and carbon components analysis of PM2.5, proceeded with a study focus on the pollution characteristics of carbon components in PM2.5, Major conclusions are as follow： The average concentrations of OC, EC were 12.1gg/m3 and 4.8μg/m^3, respectively, which accounted for 12.0% and 4.8% of PM2.5 total mass. OC was the dominant carbon components in PM2.5, the contribution in spring, summer and autumn was all above 10.0%. The OC/EC ratios in the spring, summer and autumn of the PM2.5 were 2.4, 2.4 and 2.7, respectively, and were more than 2, which showed that there was different degree secondary organic pollution in spring, summer and autumn. The contribution of SOC in spring, summer and autumn of Jinan were 14.8%, 56.9% and 49.6%, respectively. The meteorological conditions of the long sunshine duration of summer and autumn promoted the formation of SOC. The mass concentration of SOC was 4.8μg/m3, which occupied 40.4% of TC, showed that SOC had been an important contributor to PM25 in Jinan. By analyzing the contents of 8 carbon fractions in PM25, it was found that carbon compositions were similar in spring, sum- mer and autumn at the sample point. The characteristic component was EC1 in the three seasons, which showed that the gasoline vehicle exhaust was the main pollution source of Jinan.