深圳工业区夏秋季大气挥发性有机物来源研究

The long-term online observation of atmospheric volatile organic compounds (VOCs) was carried out in the northern industrial area of Shenzhen from July to October 2021 to analyze pollution characteristics of VOCs during ozone polluted days and non-polluted days. The refined source apportionment of VOCs was carried out by using ratio method of characteristics species and positive matrix factorization (PMF) model to analyze the concentration and OFP contribution of each emission source and the influence of meteorological conditions. The results showed that the average mixing ratio of TVOCs was 50.48×10^-9, of which alkane contributed the most, followed by OVOCs and aromatic, accounting for 41.3%, 22.2% and 17.0% respectively. Comparing with non-polluted days, the mixing ratio of OVOCs increased the most during polluted days (63.1%). The ratio of characteristic species indicated that the area was mainly affected by vehicle emission and industrial solvent use. Five VOCs emission sources were determined by the PMF model, of which vehicle emissions and gasoline volatilization contributed the most to the concentration (28.2%), followed by solvent use (22.9%), process emissions (25.0%) and biomass combustion (20.4%). OFP contribution of process emissions and solvent use exceeded 70% during polluted days. The distribution characteristics with wind speed and direction indicated that vehicle emissions and gasoline volatilization, process emissions and solvent use mainly came from local emissions, while biomass combustion was more influenced by transmission from northeast. It is suggested to intensify local industrial and traffic source controls, while also paying attention to biomass combustion and strengthening joint prevention and control with neighboring areas.