Ye Zhao-Lian, Liu Jia-Shu, Li Qing, Ma Shuai-Shuai, Xu Peng
School of Chemical and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, China.
School of Environmental Science and Engineering, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Huan Jing Ke Xue. 2017 Nov 8;38(11):4469-4477. doi: 10.13227/j.hjkx.201704295.
To better understand the characterization and sources of carbonaceous components, a total of 60 fine particle (PM) samples were collected in Changzhou during summer (July to August) and fall (October to November) of 2016. The average mass concentrations of PM, organic carbon (OC), and elemental carbon (EC) during this study period were observed to be 73.0, 14.3 and 3.3 μg·m in summer and 84.2, 13.2, and 3.5 μg·m in fall, respectively. The average mass fraction of carbonaceous aerosols (OC+EC) in the PM measurement was estimated to be 24.3% in summer and 20.7% in fall. Eight carbonaceous fractions, resolved by following the IMPROVE-A thermal/optical reflectance protocol, showed strong correlation (>0.92) between OC2, OC3, OC4 and EC1 and close correlations between EC2 and EC3 (>0.65), indicating probable similar contributors. OC and EC were moderately correlated, suggesting complex contributions to carbonaceous aerosol. The water soluble organic carbon (WSOC) to OC ratio (WSOC/OC) in the fall (60.9%) was slightly higher than that in the summer (57.4%), while secondary organic carbon (SOC) to OC ratio (SOC/OC) was lower in the fall (49.0%) compared with the summer (52.5%). The SOC/OC ratio was lower than the WSOC/OC for both seasons, suggesting that part of WSOC component originates from primary emissions. The significant correlation of WSOC and SOC confirms that most SOC is water soluble. Relationships between each carbonaceous species and the principal component analysis indicate that vehicle emissions and coal combustion are the two main emission sources of carbonaceous aerosols from the observation period. Back trajectory analysis was used to indicate that carbonaceous components at sampling site are mainly affected by local emission sources and short distance transport, whereas the contribution of long-distance transmission is small.
为了更好地了解碳质成分的特征和来源，2016年夏季（7月至8月）和秋季（10月至11月）在常州共采集了60个细颗粒物（PM）样本。在本研究期间，夏季PM、有机碳（OC）和元素碳（EC）的平均质量浓度分别为73.0、14.3和3.3 μg·m，秋季分别为84.2、13.2和3.5 μg·m。PM测量中碳质气溶胶（OC+EC）的平均质量分数在夏季估计为24.3%，秋季为20.7%。按照IMPROVE-A热/光反射规程解析的八个碳质组分显示，OC2、OC3、OC4与EC1之间有很强的相关性（>0.92），EC2与EC3之间有密切相关性（>0.65），表明可能有相似的来源。OC和EC呈中度相关，表明对碳质气溶胶的贡献复杂。秋季水溶性有机碳（WSOC）与OC的比值（WSOC/OC）（60.9%）略高于夏季（57.4%），而秋季二次有机碳（SOC）与OC的比值（SOC/OC）（49.0%）低于夏季（52.5%）。两个季节的SOC/OC比值均低于WSOC/OC，表明部分WSOC组分源自一次排放。WSOC和SOC的显著相关性证实了大多数SOC是水溶性的。各碳质物种之间的关系以及主成分分析表明，在观测期内，车辆排放和煤炭燃烧是碳质气溶胶的两个主要排放源。后向轨迹分析表明，采样点的碳质成分主要受本地排放源和短距离传输的影响，而长距离传输的贡献较小。
