| 无锡市冬季典型天气PM2.5中碳组分的污染特征 |
| 摘要点击 2759 全文点击 1272 投稿时间：2014-02-11 修订日期：2014-04-04 |
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| 中文关键词 PM2.5 有机碳 元素碳 霾 二次有机碳 |
| 英文关键词 PM2.5 organic carbon elemental carbon haze SOC |
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| 中文摘要 |
| 于2013-12-03~2014-01-03在无锡市对大气细粒子（PM2.5）进行了连续采集，并用热/光透射法（TOT）分析了其中有机碳（OC）和元素碳（EC）的浓度，结合气象参数，分析了冬季霾产生过程及霾天气下碳组分的污染特征. 结果表明，采样期间共有3次霾产生过程，冷空气、风和降水成为改善空气质量最有效的途径. PM2.5、OC及EC的日均质量浓度分别为（132.38±87.17）、（22.80±9.77）和（2.08±1.63）μg ·m-3，总碳（TC，TC=OC+EC）占PM2.5的23.57%，同时TC与PM2.5之间存在较好的相关性，相关系数为（R2）0.730；采样期间，TC在PM2.5中所占的比例与PM2.5的浓度之间存在相反的变化趋势，并且在霾天气下TC所占的比例要比非霾天气小，二次无机气溶胶粒子（SO42-、NO3-、NH4+）的快速增长可能是造成霾天气下细粒子浓度较高的原因之一；OC/EC值为12.83，并且相关性较差，可能与二次污染有关，对二次有机气溶胶（SOC）进行估算：得到SOC平均质量浓度为9.04 μg ·m-3，占OC的40.96%. |
| 英文摘要 |
| The purpose of this study was to investigate the process of haze in winter and the variation of carbonaceous aerosols in haze days. Continuous measurements of PM2.5 and meteorological parameters were conducted from Dec 3rd,2013 to Jan 3rd, 2014, in Wuxi City. The carbonaceous component was quantified with the thermal/optical transmission (TOT) method. The results showed that: Three times of haze progresses occurred during the sampling period. Cold air, wind and rainfall were the most efficient ways to improve air quality. The mass concentration of PM2.5, OC and EC were (132.38±87.17) μg ·m-3, (22.80±9.77) μg ·m-3 and (2.08±1.63) μg ·m-3, respectively. The TC accounted for 23.57% of the PM2.5; at the same time, the TC and PM2.5 were found to be strongly correlated (correlation coefficients=0.730). There was a negative correlation between the ratio of carbonaceous aerosol in PM2.5 and the concentration of PM2.5, and the ratio in haze days was lower than that in normal days, which suggested that secondary inorganic particles (SO42-, NO3-, NH4+) may have a fast growth in haze days. Average OC/EC ratio was 12.83, and there was a poor correlation between OC and EC, indicating that secondary pollutants might exist. The secondary organic carbon (SOC) was estimated to be 9.04 μg ·m-3, accounting for 40.96% of OC. |
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