泰安市大气臭氧污染特征及敏感性分析

2018年5～7月对泰安市城区站点的臭氧及前体物进行在线监测,并基于特征比值法和光化学模型分析了臭氧及前体物的污染特征及臭氧生成对前体物的敏感性.结果表明,观测期间泰安市正遭受较为严重的臭氧(O_3)污染,臭氧浓度的日变化呈典型的单峰型变化,15:00左右出现最高值,氮氧化物(NO_x)和VOCs的日变化趋势整体呈现夜间高白天低的变化特征.由O_3生成效率(OPE)、VOCs/NO_x和H_2O_2/NO_z特征比值法及基于EKMA曲线的方法均得出观测期间泰安市大气O_3光化学生成偏向于NO_x敏感区及过渡区,削减NO_x和VOCs均对O_3生成具有控制作用.同时基于EKMA曲线的方法还得出在O_3前体物浓度减排时按照丙烯等效浓度(PE)与NO_x浓度比值为8∶3进行VOCs(PE)和NO_x削减可以达到O_3浓度控制的最佳效果.

Pollution Characteristics and Sensitivity Analysis of Atmospheric Ozone in Taian City

Online monitoring of ozone (O₃) and its precursors was carried out at urban stations in Taian City from May to July, 2018. The pollution characteristics of O₃ and its precursors and the sensitivity of O₃ generation to its precursors were also analyzed based on the characteristic ratio method and a photochemical model. The results indicated that Taian City was suffering from serious O₃ pollution during the observation period. The daily variation of the O₃ concentration exhibited an obvious convex trend with the highest value at approximately 15:00, whereas the concentrations of nitrogen oxide (NO_x) and VOCs had decreasing trends during the daytime and increasing trends during the night. It was concluded from the results of the characteristic ratio methods (OPE, VOCs/NO_x, and H₂O₂/NO_z) and the empirical kinetics modeling approach (EKMA) curve method that the photochemical generation of O₃ in Taian was controlled by the NO_x concentration and the transition area, which means that reducing the emissions of NO_x and VOCs has a controlling effect on O₃ pollution. Additionally, the results of the EKMA curve method also showed that the best effect of O₃ concentration control could be achieved by reducing the concentration of O₃ precursors, and reducing the concentrations of VOCs (propylene equivalent, PE) and NO_x according to a PE:NO_x concentration ratio of 8:3.