| 2020年和2021年南京城区臭氧生成敏感性和VOCs来源变化分析 |
| 摘要点击 1860 全文点击 1544 投稿时间：2022-04-19 修订日期：2022-07-07 |
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| 中文关键词 O3-VOCs-NOx敏感性 基于观测的模型(OBM) VOCs来源解析 正定矩阵因子分解(PMF)模型 南京 |
| 英文关键词 O3-VOCs-NOx sensitivity observation-based model (OBM) VOCs source apportionment positive matrix factorization (PMF) model Nanjing |
| 作者 | 单位 | E-mail | | 陆晓波 | 江苏省南京环境监测中心, 南京 210013 | lxb2003y@163.com | | 王鸣 | 南京信息工程大学环境科学与工程学院, 江苏省大气环境监测与污染控制高技术研究重点实验室, 江苏省大气环境与装备技术协同创新中心, 南京 210044 | wangming@nuist.edu.cn | | 丁峰 | 江苏省南京环境监测中心, 南京 210013 | | | 喻义勇 | 江苏省南京环境监测中心, 南京 210013 | | | 张哲海 | 江苏省南京环境监测中心, 南京 210013 | | | 胡崑 | 南京信息工程大学环境科学与工程学院, 江苏省大气环境监测与污染控制高技术研究重点实验室, 江苏省大气环境与装备技术协同创新中心, 南京 210044 | |
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| 中文摘要 |
| PM2.5和臭氧（O3）协同防控是"十四五"期间空气质量提升的重点.O3生成与其前体物挥发性有机物（VOCs）和氮氧化物（NOx）呈高度非线性关系.基于南京市城区站点2020年和2021年的4~9月O3、VOCs和NOx的连续在线监测数据，比较了两年间O3及其前体物浓度的变化，进一步利用基于观测的盒子模型（OBM）和正定矩阵因子分解（PMF）模型分析了O3-VOCs-NOx敏感性和VOCs来源.结果表明，2021年的4~9月O3日最大浓度、VOCs和NOx浓度的平均值相较于2020年同期约下降7%（P=0.031）、17.6%（P<0.001）和14.0%（P=0.004）.2020年和2021年的O3超标天NOx和人为源VOCs的平均相对增量反应活性（RIR）分别为0.17和0.14，0.21和0.14，说明O3生成处于VOCs和NOx协同控制区.基于人为源VOCs和NOx削减情景所模拟的O3生成潜势等值线（EKMA曲线）也支撑这一结论.PMF解析结果显示工业和交通排放是VOCs的主要来源，其中与工业排放相关有5个因子，包括工业液化石油气（LPG）使用、苯化工、石化、甲苯相关的工业和溶剂涂料使用，对总VOCs浓度的贡献率为55%~57%.机动车尾气和汽油挥发因子的贡献率之和为43%~45%.进一步计算各因子的RIR值，结果显示石化和溶剂涂料使用的RIR值最高，说明从臭氧防控的角度，需要优先削减这两类源的VOCs排放.随着VOCs和NOx减排措施的实施，O3敏感性和VOCs来源会改变，因此在"十四五"期间仍需持续关注，以及时调整O3防控策略. |
| 英文摘要 |
| The synergistic control of PM2.5 and ozone (O3) are the focus of air quality improvement during the 14th Five-Year Plan in China. The production of O3 shows a highly nonlinear relationship with its precursors volatile organic compounds (VOCs) and nitrogen oxides (NOx). In this study, we conducted online observations of O3, VOCs, and NOx at an urban site in downtown Nanjing from April to September of 2020 and 2021. The average concentrations of O3 and its precursors between these two years were compared, and then the O3-VOCs-NOx sensitivity and the VOCs sources were analyzed using the observation-based box model (OBM) and positive matrix factorization (PMF), respectively. The results showed that the mean daily maximum O3 concentrations, VOCs, and NOx concentrations decreased by 7% (P=0.031), 17.6% (P<0.001), and 14.0% (P=0.004) from April to September of 2021 compared with those from the same period in 2020, respectively. The average relative incremental reactivity (RIR) values of NOx and anthropogenic VOCs during the O3 non-attainment days in 2020 and 2021 were 0.17 and 0.14 and 0.21 and 0.14, respectively. The positive RIR values of NOx and VOCs indicated that O3 production was controlled by both VOCs and NOx. The O3 production potential contours (EKMA curves) based on the 50×50 scenario simulations also supported this conclusion. The PMF results showed that industrial and traffic-related emissions were the main sources of VOCs. The five PMF-resolved factors were identified as industrial emissions, including industrial liquefied petroleum gas (LPG) use, the benzene-related industry, petrochemistry, toluene-related industry, and solvent and paint use, which contributed 55%-57% of the average mass concentration of total VOCs. The summed relative contributions of vehicular exhaust and gasoline evaporation were 43%-45%. Petrochemistry and solvent and paint use showed the two highest RIR values, suggesting that VOCs from these two sources should be reduced with priority to control O3. With the implementation of VOCs and NOx control measures, the O3-VOCs-NOx sensitivity and VOCs sources have changed, and therefore we still need to follow their variations in the future to timely adjust O3 control strategies during the 14th Five-Year Plan. |
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