| 黄石市大气PM2.5中碳氮组分的污染特征及来源解析 |
| 摘要点击 3932 全文点击 2744 投稿时间：2022-04-28 修订日期：2022-05-31 |
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| 中文关键词 稳定同位素 PMF模型 后向轨迹 源解析 污染特征 |
| 英文关键词 stable isotope PMF model backward trajectory source apportionment pollution characteristics |
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| 中文摘要 |
| 基于稳定同位素技术与正定矩阵因子分解（PMF）模型，探究黄石市城区大气PM2.5中碳氮组分的污染特征和来源.结果表明，黄石市城区大气PM2.5中总碳浓度［ρ（TC）］与总碳同位素组成（δ13 CTC）均呈冬高夏低的季节性变化特征，夏季分别为（4.4±1.2）μg ·m-3和（-26.3±0.5）‰，冬季分别为（9.9±3.5）μg ·m-3和（-25.5±0.5）‰；总氮浓度［ρ（TN）］在夏季［（9.1±9.1）μg ·m-3］明显低于冬季［（62.4±26.4）μg ·m-3］，而总氮同位素组成（δ15 NTN）在夏季［（12.8±1.9）‰］较冬季［（2.9±4.0）‰］明显富集.除本地源贡献外，黄石市PM2.5中碳氮组分主要受湖南北部近距离区域排放和西北方向远距离传输影响.贝叶斯混合模型（MixSIAR）与PMF模型解析出机动车排放源为PM2.5中碳组分的主要来源，贡献率分别为38.9%和39.3%.MixSIAR结果表明NOx排放源相对NH3排放源对不同季节PM2.5中氮组分的影响更大，且夏季（80%）贡献高于冬季（66.8%），其中燃煤（夏季：36.1%；冬季：20.2%）排放产生的NOx贡献最大，而PMF模型表征出氮质组分主要来源为机动车排放（59.8%）.通过多模型结合分析克服了单模型解析的不确定性和主观性，为有效应对城市PM2.5污染问题提供理论依据. |
| 英文摘要 |
| Based on stable isotope technology and a PMF model, the pollution characteristics and sources of carbon and nitrogen components in ambient PM2.5 in Huangshi City were explored. The results showed that the total carbon concentration[ρ(TC)] and the total carbon isotopic composition (δ13CTC) in ambient PM2.5 in Huangshi City both showed seasonal variation characteristics of being high in winter and low in summer, with values of (4.4±1.2) μg·m-3 and (-26.3±0.5)‰ in summer and (9.9±3.5) μg·m-3 and (-25.5±0.5)‰ in winter, respectively. The total nitrogen concentration[ρ(TN)]was significantly lower in summer[(9.1±9.1) μg·m-3]than that in winter[(62.4±26.4) μg·m-3], whereas the total nitrogen isotopic composition (δ15NTN) was obviously enriched in summer[(12.8±1.9)‰]compared with that in winter[(2.9±4.0)‰]. In addition to the contribution from local sources, the carbon and nitrogen components were mainly affected by the short-range regional emission in northern Hunan and the long-distance transport in the northwest. The MixSIAR model and the PMF model indicated that the vehicle emission source was the main source of carbon components in PM2.5, with contribution rates of 38.9% and 39.3%, respectively. MixSIAR results showed that NOx emission sources had a greater impact on nitrogen components in PM2.5 of different seasons than NH3 emission sources, and their contribution was higher in summer (80%) than that in winter (66.8%), among which the NOx emissions from coal combustion (summer:36.1%; winter:20.2%) had the largest contribution. By contrast, the PMF model indicated that the main source of nitrogen components was vehicle emissions (59.8%). Combining multiple models to overcome the uncertainty and subjectivity of single-model analysis can provide a theoretical basis for actively controlling and reducing fine particulate matter emissions and effectively dealing with urban aerosol pollution. |
