【摘要】 近几年,PM_2.5浓度上升导致灰霾事件频繁发生,已经引起了广泛的关注。碳组分是PM_2.5中的重要组分,被认为是灰霾形成和转化的重要因素,因此,研究PM_2.5中含碳组分的来源及其化学过程具有重要的意义。本研究于2016年12月至2017年8月期间在南昌地区共采集105个PM_2.5样品,分析了PM_2.5样品中总碳（TC）浓度及其碳同位素(δ¹³C)。结果表明,采样期间TC的年平均浓度为（12.1±2.1）μg/m³,总体上呈现冬季高、夏季低的变化趋势,可能是受不同季节气象因素和来源变化的影响。δ¹³C的年平均值为（-26.1±0.2）‰,总体上呈现冬季高、春季低的变化趋势,可能是受不同来源的影响。利用贝叶斯模型计算南昌地区PM_2.5中TC主要来源于C₃植物燃烧和机动车尾气,年源贡献分别为49.3%和28.7%;其次是煤燃烧和C₄植物燃烧,年源贡献分别为17.7%和4.2%。春季δ¹³C值偏低是由于C₃植物燃烧贡献相对较高,而冬季δ¹³C值偏高则是煤燃烧贡献增加。更多还原

【Abstract】 The frequent haze events caused by the rise of PM_2.5 concentrations in the recent years have attracted extensive attention.As an important component of PM_2.5,carbon is considered as an important factor for haze formation and transformation.Therefore,studying the source and chemical process of the carbon component in PM_2.5 is significant.In this study,PM_2.5 samples were collected in Nanchang from December 2016 to August 2017The total carbon（TC）concentration and carbon isotope(δ¹³C)in the PM_2.5 samples were then analyzed.The results showed that the TC concentrations in PM_2.5 and the annual average ofδ¹³C were generally significantly higher in winter than those in summer.During the sampling period,the annual average concentration of TC was（12.1±2.1）μg/m³,which may be influenced by meteorological factors and source changes in different seasons Meanwhile,the annual average ofδ¹³C was（-26.1±0.2）‰,which may be affected by different sources.Through the Bayesian model,we calculated that TC in PM_2.5 in the Nanchang area mainly came from C₃ plant combustion and motor vehicle exhaust,with annual contributions of 49.3%and 28.7%,respectively.Coal burning and C₄ plant burning also contributed 17.7%and 4.2%,respectively.The results illustrated that the lowδ¹³C value in spring was caused by the relatively high contribution of C₃ plant combustion,while the higherδ¹³C in winter was caused by the increased contribution of coal combustion.更多还原