何雨璇,常运华,张和艳,郭仕祥,白琰婧,高硕,郭照冰.基于隧道PM2.5取样研究南京市机动车尾气颗粒物排放特征[J].环境科学学报,2021,41(11):4430-4438
基于隧道PM2.5取样研究南京市机动车尾气颗粒物排放特征
- Emission characteristics of particulate emitted by motor vehicles in Nanjing based on PM2.5 sampling in tunnel
- 基金项目：国家自然科学基金项目（No.41873016，91544229-02，41625006）；江苏省“333人才工程”项目；江苏省“青蓝工程”项目
- 何雨璇
- 1. 南京信息工程大学环境科学与工程学院, 南京 210044;2. 江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044
- 常运华
- 南京信息工程大学应用气象学院, 南京 210044
- 张和艳
- 1. 南京信息工程大学环境科学与工程学院, 南京 210044;2. 江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044
- 郭仕祥
- 1. 南京信息工程大学环境科学与工程学院, 南京 210044;2. 江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044
- 白琰婧
- 1. 南京信息工程大学环境科学与工程学院, 南京 210044;2. 江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044
- 高硕
- 1. 南京信息工程大学环境科学与工程学院, 南京 210044;2. 江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044
- 郭照冰
- 1. 南京信息工程大学环境科学与工程学院, 南京 210044;2. 江苏省大气环境监测与污染控制高技术研究重点实验室, 南京 210044
- 摘要：为研究南京地区机动车尾气颗粒物排放特征，于2020年8月对南京富贵山隧道内和隧道外进行PM2.5采集，对样品中的水溶性离子、碳质组分的分布特征进行分析，综合总碳同位素（δ13C）与主成分分析（PCA）探究隧道内PM2.5来源，并使用质量平衡模型计算了污染物的平均排放因子.结果显示，隧道入口、出口及隧道外早晚高峰期内PM2.5平均值分别为（69.25±24.19）、（116.67±28.70）和（60.87±16.08）μg·m-3，隧道内污染程度明显高于隧道外.隧道内外二次无机气溶胶（SNA）分布略有不同，隧道外NH4+主要以（NH4）2SO4的形式存在，其次为NH4NO3；隧道内则主要以（NH4）2SO4和NH4NO3的形式存在.隧道内δ13C存在着较小的分馏，平均值为-26.0‰±0.72‰，综合δ13C与主成分分析，隧道内PM2.5主要来源于机动车的一次排放、尾气颗粒物的二次转化和扬尘.富贵山隧道中PM2.5、EC、OC的平均排放因子分别为82.86、24.22、7.07 mg·km-1·veh-1，与国内外其他隧道实验排放因子的对比结果显示，通过柴油车比例为6%的富贵山隧道远低于柴油车比例较高的地区.
- Abstract：To explore chemical characteristics of particulate emitted by motor vehicles, PM2.5 was collected and analyzed from inside and outside of Fugui Mountain Tunnel in Nanjing during August 2020. This study explored and investigated the water-soluble ions and carbon components in the samples. In addition, a combination of stable carbon isotope (δ13C) and principal component analysis (PCA) revealed the source of PM2.5. Finally, the average emission factors (EF) of pollutants were calculated by using mass balance model. The results showed that the average concentrations of PM2.5 at the entrance, exit and outside of the tunnel were (69.25±24.19), (116.67±28.70) and (60.87±16.08) μg·m-3, respectively. The average pollutant concentration inside of the tunnel was significantly higher than that outside of the tunnel. The distribution of secondary inorganic aerosol inside and outside of the tunnel was slightly different. Outside of the tunnel NH4+ mainly existed in the form of (NH4)2SO4, followed by NH4NO3. While inside of the tunnel, NH4+ mainly existed in the form of (NH4)2SO4 and NH4NO3. There was a small fractionation of δ13C in the tunnel, with an average value of -26.0‰±0.72‰. Combined with δ13C and PCA, PM2.5 in the tunnel mainly comes from primary vehicle emissions, secondary conversion of exhaust particulate matter and dust. The EF of PM2.5, EC, and OC in tunnel were 82.86, 24.22 and 7.07 mg·km-1·veh-1, respectively. Compared with other tunnel, the results showed that the EF in the Fugui Mountain Tunnel (the proportion of diesel cars passing was 6%) was lower than that of tunnels with a high proportion of diesel vehicle passing.
