廊坊开发区8~9月O3污染过程VOCs污染特征及来源分析

使用ZF-PKU-1007大气挥发性有机物（VOCs）在线连续监测系统，于2018年8月25日至9月30日在廊坊开发区对99种VOCs进行监测，并开展不同O₃污染情况下ω（VOCs）特征、大气反应活性及来源研究.结果表明，监测期间廊坊开发区ω（VOCs）平均为（75.17±38.67）×10^-9，O₃污染日和清洁日ω（VOCs）平均分别为（112.33±30.96）×10^-9和（66.25±34.84）×10^-9，污染日ω（VOCs）较清洁日偏高69.6%；对于大气反应活性，污染日和清洁日VOCs对臭氧生成潜势（OFP）的贡献均以醛酮类、芳香烃、烯烃和烷烃为主，对于羟基消耗速率（L_·OH），污染日以芳香烃（30.0%）和烯烃（25.8%）为主，而清洁日烯烃贡献（29.8%）略高于芳香烃（28.0%）；PMF源解析结果显示，机动车排放（34.4%）、溶剂使用及挥发源（31.7%）、石化工业源（15.7%）、燃烧源（11.1%）和植物排放源（7.9%）为监测期间VOCs的主要来源，另外污染日溶剂使用及挥发源、植物源排放较清洁日升高13.1%和1.2%，可能与污染日温度较高有关.因此，机动车排放和溶剂使用及挥发为廊坊开发区8~9月VOCs的控制重点.

Characteristics and Source of VOCs During O3 Pollution Between August to September, Langfang Development Zones

A total of 99 volatile organic compound(VOC) species were detected the Langfang development zones based on continuous monitoring using a ZF-PKU-1007 between August 25 and September 30, 2018. The concentrations, reactivity, and sources of VOCs were studied under different O₃ concentrations using compositional analysis. The results showed that the average VOCs concentration during the research period was(75.17±38.67)×10^-9, and was(112.33±30.96)×10^-9, (66.25±34.84)×10^-9 on pollution days and cleaning days, respectively(VOCs concentrations were 69.6% higher on pollution days). The contribution of VOCs species to the ozone formation potential(OFP) were ranked in the order aldehydes > aromatics > alkenes > alkanes. In the case of L_·OH, the main contributions were from aromatics(30.0%) and alkenes(25.8%) on pollution days, while the contribution from aromatic alkenes(29.8%) was a slightly higher than aromatics(28.0%) on cleaning days. By applying the positive matrix factorization(PMF) model, five major VOCs sources were extracted, namely vehicle emissions(34.4%), solvent usage and evaporation(31.7%), the petrochemical industry(15.7%), combustion(11.1%), and plant emissions(7.9%). The contributions of solvent usage and evaporation and plant emission sources on pollution days were 13.1% and 1.2% higher than on cleaning days, respectively, which was likely due to relatively higher temperatures on these days. Therefore, vehicle emissions and solvent usage and evaporation should be priorities in VOCs control strategies for the Langfang development zones between August to September.