南京江北化工园区挥发性有机物走航观测

挥发性有机物（VOCs）是大气中1类具有较大健康危害的污染物，同时也是大气中二次有机气溶胶和臭氧生成的重要前体物。首次使用搭载了单光子电离质谱仪（SPI-MS）的走航观测车，在2018年3月对南京江北化工园区环境空气中的VOCs进行了为期4 d的走航观测。观测期间，总VOCs的平均浓度为133.3 μg/m3，夜间平均浓度（143.6 μg/m3）较日间（123.1 μg/m3）偏高，工作日平均浓度（226.7 μg/m3）远高于周末（39.9 μg/m3）。同时还获得了高时间和高空间分辨率的VOCs分布特征，并详细分析了走航路线途经的3个重点区域（南钢-南化、扬子石化和化工大道区域）的特征污染物、浓度变化及主要排放源（企业）。总体来看，VOCs组成以烷烃和芳香烃浓度占比最大（均为31%），其次为烯烃（25%）和卤代烃（13%）；但对臭氧生成潜势的贡献，则是烯烃最大（56%），其次为芳香烃、烷烃和卤代烃，分别占32%、9%和3%。该结果为化工园区VOCs的减排管理及区域臭氧污染控制提供参考。

MOBILE MEASUREMENT OF AMBIENT VOLATILE ORGANIC COMPOUNDS IN THE JIANGBEI CHEMICAL INDUSTRIAL PARK OF NANJING,CHINA

Volatile organic compounds (VOCs) are a group of air pollutants with potentially adverse health effects, and also important precursors of both secondary organic aerosols and ozone. In this work, an online single photon ionization mass spectrometer (SPI-MS) was installed on a vehicle, and for the first time, we conducted a four-day mobile measurement of VOCs in the Nangjing Jiangbei Chemical Industry Park during March 2018. During the sampling period, the average concentration of total VOCs was 133.3 μg/m3, nighttime mean concentration (143.6 μg/m3) was higher than that during daytime (123.1 μg/m3), and mean mass concentration of workdays (226.7 μg/m3) was found to be much higher than that of weekend (39.9 μg/m3). We also obtained highly time-and spatially-resolved distributions of VOCs, and elucidated the characteristic species, and variations and dominant sources (factories) of the three key zones (Nangang Nanhua, Yangzi Shihua, and Huagong Dadao). Overall, alkanes and aromatics were the major contributors (both 31%) of the total VOCs, followed by alkenes (25%) and halocarbons (13%); while in terms of ozone formation potential, alkenes was the largest contributor (56%), followed by aromatics (32%), alkanes (9%) and halocarbons (3%). Our findings here could provide useful insights and guidances into the VOCs reduction measures and local ozone pollution control.