沈阳市环境空气中挥发性有机物污染特征及来源解析

基于2019年沈阳市4个不同功能区挥发性有机物(VOCs)小时分辨率的在线监测数据,分析了环境空气中VOCs的污染特征及来源。结果表明,观测期间沈阳市环境空气中VOCs日平均体积分数为(31.5±13.3)×10~(-9),4个功能区VOCs体积分数均呈现出冬季明显大于夏季的特征;工业区环境空气中VOCs体积分数明显高于其他功能区。商业交通居民混合区、文化居民混合区、郊区VOCs体积分数呈现明显双峰结构,工业区双峰结构不明显。工业区VOCs以新鲜排放为主,而其他3个区域为老化气团的传输。工业区春、夏季环境空气中VOCs来源包括燃料挥发源(26.90%)、溶剂与涂料源(17.69%)、燃烧源(16.40%)、化工源(15.69%)、交通源(7.57%)和炼油炼焦源(4.15%)。秋、冬季VOCs的来源包括燃烧源(30.77%)、溶剂与涂料源(20.26%)、燃料挥发源(18.79%)、化工源(11.54%)、炼油炼焦源(9.34%)和交通源(5.51%)。

Pollution Characteristic and Source Apportionment of VOCs in Shenyang

Based on the hourly resolution online monitoring data of volatile organic compounds (VOCs) in four different functional areas in Shenyang in 2019, the pollution characteristics and sources of VOCs in the ambient air were analyzed.The results showed that the daily average volume fraction of VOCs in the ambient air of Shenyang was (31.5±13.3)×10^-9 during the observation period, and the volume fraction of VOCs in four different functional areas were all obviously larger in winter than in summer.The volume fraction of VOCs in the ambient air of industrial areas was significantly higher than that of other functional areas.The variation of VOCs showed a obvious bimodal structure in mixed area of commercial traffic residents, mixed area of cultural residents and suburban vegetation area while that of industrial area was not obvious.VOCs in the industrial area were mainly fresh emissions, while the other three areas were the transmission of aging air masses.Based on PMF model analysis, seven sources and its contribution were identified in industrial area, including fuel volatilizing source (26.90%), solvent and coating source (17.69%), combustion source (16.40%), chemical source (15.69%), transportation source (7.57%) and oil refining and coking source (4.15%) in spring and summer, and including combustion sources (30.77%), solvents and coatings sources (20.26%), fuel volatilization sources (18.79%), chemical sources (11.54%), oil refining and coking sources (9.34%) and transportation sources (5.51%) in autumn and winter.