| 重庆典型城区冬季碳质气溶胶的污染特征及来源解析 |
| 摘要点击 1150 全文点击 255 投稿时间：2023-02-21 修订日期：2023-04-11 |
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| 中文关键词 碳质气溶胶 污染过程 二次有机碳 来源解析 重庆 |
| 英文关键词 carbonaceous aerosols pollution period secondary organic carbon source apportionment Chongqing |
| 作者 | 单位 | E-mail | | 彭超 | 重庆市生态环境科学研究院, 重庆 401147
中国环境科学研究院西南分院, 重庆 401147
城市大气环境综合观测与污染防控重庆市重点实验室, 重庆 401147 | pengchao0623@sina.com | | 李振亮 | 重庆市生态环境科学研究院, 重庆 401147
中国环境科学研究院西南分院, 重庆 401147
城市大气环境综合观测与污染防控重庆市重点实验室, 重庆 401147 | zhenliangli@163.com | | 向英 | 重庆市生态环境科学研究院, 重庆 401147
中国环境科学研究院西南分院, 重庆 401147
城市大气环境综合观测与污染防控重庆市重点实验室, 重庆 401147 | | | 王晓宸 | 重庆市生态环境科学研究院, 重庆 401147
中国环境科学研究院西南分院, 重庆 401147
城市大气环境综合观测与污染防控重庆市重点实验室, 重庆 401147 | | | 汪凌韬 | 重庆市生态环境科学研究院, 重庆 401147
中国环境科学研究院西南分院, 重庆 401147
城市大气环境综合观测与污染防控重庆市重点实验室, 重庆 401147 | | | 张晟 | 重庆市生态环境科学研究院, 重庆 401147
中国环境科学研究院西南分院, 重庆 401147
城市大气环境综合观测与污染防控重庆市重点实验室, 重庆 401147 | | | 翟崇治 | 重庆市生态环境科学研究院, 重庆 401147
中国环境科学研究院西南分院, 重庆 401147
城市大气环境综合观测与污染防控重庆市重点实验室, 重庆 401147 | | | 陈阳 | 中国科学院重庆绿色智能技术研究院, 重庆 400714 | | | 杨复沫 | 四川大学建筑与环境学院, 成都 610065 | | | 翟天宇 | 北京大学环境科学与工程学院, 北京 100871 | |
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| 中文摘要 |
| 于2021年1~2月在重庆典型城区万州区（WZ）、渝北区（YB）和双桥区（SQ）同步采集PM2.5样品,分析冬季碳质气溶胶的污染特征、来源及潜在源区.结果表明,观测期间SQ的ρ（PM2.5）、ρ（OC）和ρ（EC）均值分别为（72.6 ± 33.3）、（18.2 ± 8.2）和（4.4 ± 1.7）μg·m-3,高于WZ[（67.2 ± 30.3）、（17.2 ± 7.4）和（5.1 ± 2.4）μg·m-3]和YB[（63.4 ± 25.7）、（15.4 ± 6.3）和（4.2 ± 1.9）μg·m-3].与清洁日相比,WZ污染日EC浓度及其对总碳的贡献率均涨幅最大（103.0%和8.1%）,但OC/EC值下降最明显（-10.5%）,表明WZ污染日碳质气溶胶的一次排放明显增强.观测期间SQ和YB的ρ（SOC）均值分别为（7.7 ± 4.8）μg·m-3和（6.9 ± 2.8）μg·m-3,明显高于WZ[（4.5 ± 1.9）μg·m-3],表明二次转化对SQ和YB碳质气溶胶的影响相对较大.此外,与WZ不同,SQ和YB的SOC/OC值整体随PM2.5浓度上升而增大,且SOC浓度与气溶胶液态水含量（AWC）、NO2浓度和NOR值等均显著线性相关（P<0.01）,表明通过液相反应生成含—NO2官能团的SOC可能是SQ和YB碳质气溶胶浓度持续上升的主要因素.正定矩阵因子（PMF）解析结果表明,WZ的生物质/煤炭燃烧混合源贡献率（47.4%）明显高于YB（34.2%）和SQ（38.1%）,而YB受汽油车排放和二次转化的影响较为突出.浓度权重轨迹分析（CWT）结果表明,各城区污染日碳质气溶胶主要受本地及其东北方向相邻城区（如长寿区）的影响. |
| 英文摘要 |
| To investigate the characteristics, source apportionment, and potential source areas of carbonaceous aerosols in Chongqing during winter, PM2.5 samples were collected from January 2021 to February 2021 in the urban areas of Wanzhou (WZ), Yubei (YB), and Shuangqiao (SQ). The results showed that the average mass concentrations of PM2.5, OC, and EC in SQ were (72.6 ±33.3), (18.2 ±8.2), and (4.4 ±1.7) μg·m-3, respectively, higher than those in WZ[(67.2 ±30.3), (17.2 ±7.4), and (5.1 ±2.4) μg·m-3] and YB[(63.4 ±25.7), (15.4 ±6.3), and (4.2 ±1.9) μg·m-3]. Compared with that during the clear period, the concentration and fraction of EC in total carbon increased by 103.0% and 8.1%, respectively, in WZ compared to that in other areas during pollution period, whereas the OC/EC ratio was decreased significantly (-10.5%), indicating that the primary emission of carbonaceous aerosols increased significantly during the pollution period. The average mass concentrations of secondary organic carbon (SOC) in SQ and YB were (7.7 ±4.8) μg·m-3 and (6.9 ±2.8) μg·m-3 significantly higher, respectively, than that in WZ[(4.5 ±1.9) μg·m-3] during the campaign. This indicated that the secondary transformation had a greater influence on the carbonaceous aerosols in SQ and YB than that in WZ. Furthermore, in contrast to that in WZ, the ratios of SOC/OC were increased with the increase in PM2.5 concentrations, and significant correlations between SOC concentration and aerosol water content, NO2 concentration, and the value of NOR were observed in SQ and YB (P < 0.01), indicating that the increasing of carbonaceous aerosol concentrations might be mainly driven by the SOC with -NO2 groups produced by aqueous chemical reactions during winter in SQ and YB. The positive definite matrix factor (PMF) results in these urban areas showed that the contribution of biomass/coal combustion source in WZ (47.4%) was significantly higher than that in YB (34.2%) and SQ (38.1%), whereas the gasoline motor vehicle emission and secondary transformation impacts were more significant in YB. The results of the concentration weighted trajectory (CWT) showed that the potential sources of carbonaceous aerosols were mainly the local and northeastern parts of these urban areas (such as Changshou). |
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