深圳西部城区大气O3污染特征及超标成因

利用近5a深圳西部城区（大学城）大气臭氧（O₃）在线监测数据，结合深圳大学城超级站大气复合污染综合观测，获取了大气O₃演变趋势，并探究O₃超标日气象条件及其前体物的组成变化以期掌握大气O₃超标成因.结果表明，深圳大学城大气O₃日最大8h平均体积分数上升速度达1.1×10^-9/a，超标率达到6%以上.高温低湿的气象条件更容易促进大气O₃生成，高温时光化学反应强烈有利于O₃的本地生成，而低湿可能不利于O₃的湿去除从而导致污染积累.挥发性有机物（VOCs）不同组分在O₃超标日上升幅度（70%~95%）明显高于NOx（28%），且O₃高值浓度分布在高VOCs低NOx区域，说明深圳大学城大气O₃生成主要受VOCs控制.O₃超标日的甲苯与苯比值（T/B）在夜间超过10表明可能存在大量工业排放；而含氧挥发性有机物（OVOCs）在午间（12：00~14：00）的消耗相较于非超标日高出了1倍左右，表明工业活动排放的OVOCs对白天O₃生成可能贡献显著.

Study on the characteristics and the cause of atmospheric O3 pollution in western urban of Shenzhen

Based on the online monitoring data of atmospheric O₃ at University Town that located in the western Shenzhen in the past 5years, combined with the comprehensive observation of atmospheric pollutants, the evolution trend of atmospheric O₃ was obtained. In addition, the variations of meteorological conditions and the precursor's composition of O₃ during the exceeding standard periods were deeply explored in order to grasp the causes. The resultsshow that the increase rate of the maximum 8-hour average mixing ratio of atmospheric O₃ was 1.1×10^-9/a, and the exceed-standard rate was over 6%. High temperature and low humidity meteorological conditions were more likely to promote atmospheric O₃ formation. The increase of VOCs in the O₃ exceeding standard periods (70%~95%) was significantly higher than that of NO_x (28%), and the O₃ high concentration was distributed in the high VOCs and low NO_x region, indicating that the O₃ formation was mainly controlled by VOCs in University Town of Shenzhen. The toluene to benzene ratio (T/B) over 10at night during the O₃ exceeding standard periods suggesting that there may be a large amount of industrial emissions, while the consumption of OVOCs doubled at noon, indicating that OVOCs emitted by industrial activities may contribute significantly to daytime O₃ production.