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在夏秋季对我国北方某石化炼油厂附近大气中的O3及其前体物的体积分数进行了监测,分析了其日变化特征及其与气象要素的相关性,并分析了O3超标与未超标期间气象条件与O3前体物的特征。结果表明,夏秋季炼油厂附近O3体积分数超标严重。O3体积分数呈单峰型日变化,在午后15:00左右出现日最大值,夜晚体积分数较低;而NOx和VOCs体积分数与O3相反,白天较低,夜间较高,并呈现双峰型日变化。烯烃和苯系物体积百分比的日变化趋势为先降低后升高,烷烃体积百分比的日变化趋势则相反。夏秋季O3体积分数变化与温度、风速成正相关,与相对湿度成负相关。O3超标与未超标期间前体物体积分数及气象条件均存在显著差异,温度、相对湿度在O3超标期间均大于未超标期间,风速则相反。NO和VOCs体积分数在O3超标期间均小于未超标期间,而NO2体积分数差别不大。在O3体积分数最大的午后14:00,烯烃和苯系物体积百分比在O3超标期间小于未超标期间。
In summer and autumn, the volume fraction of O3 and its precursors in the atmosphere near a petrochemical refinery in the north of China was monitored, its diurnal variation characteristics and its correlation with meteorological elements were analyzed, and the relationship between O3 over and under Meteorological conditions during the period and the characteristics of O3 precursors. The results show that the O3 volume fraction near the refinery in summer and autumn is seriously exceeded. The O3 volume fraction showed a diurnal variation, with a daily maximum at about 15:00 in the afternoon and a low volume fraction at night. However, the volume fraction of NOx and VOCs was opposite to that of O3, lower at daytime and higher at night, Daily change. The daily variation trend of the volume percentages of alkene and benzene series is the first decrease and then the increase, and the diurnal variation trend of alkane volume percentage is the opposite. The changes of O3 volume fraction in summer and autumn were positively correlated with temperature and wind speed and negatively correlated with relative humidity. There were significant differences in the volume fraction of precursor and meteorological conditions between O3 exceeding and not exceeding the standard. The temperature and relative humidity were both higher than the non-over-standard O3 period and the opposite was the wind speed. The volume fraction of NO and VOCs in the O3 exceeded period is less than the non-exceeded period, while the NO2 volume fraction difference is not big. At 14:00, the volume fraction of olefins and benzene compounds in the O3 volume fraction was less than that of the non-over-standard period.