济源市疫情防控期间VOCs的变化特征、臭氧生成潜势及来源解析

采用挥发性有机物(VOCs)在线监测仪(EXPEC 2000-MS)于2020年1月1日-2月11日对济源市环境空气中VOCs进行监测,分析了疫情防控前和期间TVOCs及其组分的变化特征、臭氧生成潜势(OFP)及来源解析.结果表明,疫情防控期间济源市TVOCs浓度均值为121.7×10-9,比疫情防控前增加了61.2％...

Characteristics, ozone formation potential and source apportionment of VOCs during epidemic prevention in Jiyuan

Ambient volatile organic compounds (VOCs) in Jiyuan city were determined by an online monitor (EXPEC 2000-MS) from January 1 to February 11, 2020. In this study, the diurnal characteristics and ozone generation potential (OFP) of ambient VOCs were analyzed, source apportionment of VOCs were determined by characteristic ratios and Positive Matrix Factorization (PMF) model before and during epidemic prevention. The results showed that TVOCs in Jiyuan during epidemic prevention period was 121.7×10^-9, which was 61.2% higher than that before epidemic prevention. Compare to the results before epidemic prevention, concentrations of alkanes, alkynes and alkenes decreased significantly, while halogenated hydrocarbons and OVOCs increased significantly. Major VOCs species during epidemic prevention were ethanol, acetone, acetylene and bromomethane. The contribution of VOCs species to OFP before epidemic prevention in Jiyuan was olefins, the key active components were ethylene, 1-butene, acetylene, etc. However, the key active components during epidemic prevention were ethanol, ethylene, acrolein, toluene, etc, which suggested that the contribution of OVOCs to OFP could not be ignored during epidemic prevention. Based on PMF model, major sources contributed to TVOCs during epidemic prevention in Jiyuan were combustion (33%)>disinfectant (31%)>industrial process (17%)>biogenic source (8%)>solvent use (7%), gasoline vehicle exhaust(7%)> diesel vehicle exhaust (6%). The contribution of vehicle exhaust, industrial process and solvent use to TVOCs in Jiyuan was significantly reduced 17%, 17% and 10%, respectively. The contribution of disinfectant, including ethanol and chlorine-containing disinfectant (trichloromethane, chloroethane, etc.) to TVOCs was increased 29% during epidemic prevention.