天津工业区春夏季VOCs污染特征及精细化来源解析

2021年3—8月，采用热脱附气相色谱质谱法对天津工业区环境空气中109种挥发性有机物（VOCs）进行离线监测，研究了VOCs组成特征、臭氧生成潜势（OFP）及来源，并对工业源进行精细化分析。结果表明：观测期间VOCs浓度为（46.6±19.7）~（136.8±55.7）µg/m³，对VOCs浓度贡献较高的物种是烷烃、卤代烃、含氧挥发性有机物（OVOCs），烷烃、芳香烃浓度呈中午低、早晚高的日变化趋势，OVOCs反之；OFP贡献占比较大的物种有烷烃、芳香烃、烯烃和OVOCs，烷烃的OFP贡献占比主要受其浓度占比影响，夏季芳香烃、烯烃的OFP贡献占比明显升高，臭氧（O₃）治理应加强二者的排放管控。来源解析显示，春夏季VOCs的主要来源为工业源、溶剂使用源、柴油车尾气排放源、油气挥发源和天然源。工业源精细化分析表明，芳香烃浓度与焦炭、纯碱产量，OVOCs浓度与天然气、乙烯、农用氮磷钾化肥产量，卤代烃浓度与天然气、汽车、农用氮磷钾化肥、纯碱产量，烯烃浓度与发电设备产量均呈正相关，初步判断，本地区环境空气中的芳香烃、OVOCs、卤代烃、烯烃可能来自于以上细分工业企业。

Pollution characteristics and refined source apportionment for VOCs in Tianjin Industrial Area in spring and summer

109 volatile organic compounds (VOCs) in the ambient air of Tianjin Industrial Area were monitored offline from March 2021 to August 2021 by thermal desorption gas chromatography-mass spectrometry method. The composition characteristics, ozone formation potential (OFP) and sources of VOCs were studied, and refined analysis of industrial emission sources was carried out. The results showed that VOCs concentrations fluctuated between (46.6±19.7) and (136.8±55.7) µg/m3 during the observation period, with alkanes, halogenated hydrocarbons and oxygenated volatile organic compounds (OVOCs)contributing more to VOCs concentrations, and alkanes and aromatic hydrocarbons showed a daily trend of low at noon and high in the morning and evening, while OVOCs did the opposite. Alkanes, aromatic hydrocarbons, olefin and OVOCs accounted for a large proportion of OFP contribution, the contribution proportions of alkanes to OFP were mainly influenced by their percentage of concentration, the contribution proportions of aromatic hydrocarbons and olefins to OFP was significantly higher in summer, and their emission control should be strengthened in order to control ozone (O3). Source apportionment showed that the main emission sources in spring and summer were industrial sources, solvent use sources, diesel vehicle exhaust emissions sources, oil vapour volatilisation sources and natural sources. The refined analysis of industrial sources showed a positive correlation between the concentration of aromatic hydrocarbons and the production of coke and soda ash, a positive correlation between the concentration of OVOCs and the production of natural gas, ethylene and agricultural nitrogen, phosphorus and potassium fertilizers, a positive correlation between the concentration of halogenated hydrocarbons and the production of natural gas, automobiles, agricultural nitrogen, phosphorus and potassium fertilizers, and soda ash, and a positive correlation between the concentration of olefins and the production of power generation equipment. It was preliminarily determined that the aromatic hydrocarbons, OVOCs, halogenated hydrocarbons and olefins in the ambient air of the region were likely to come from these significantly correlated sub-segments of industrial enterprises.