江门市2019年9月污染过程分析

Analysis of Pollution Process in Jiangmen City in September 2019

2019年9月14日-30日,江门市出现了一次臭氧重污染过程,其中共发生了四天轻度污染,六天中度污染,五天重度污染。污染的原因主要是:受副热带高压控制和台风外围天气条件影响,大气扩散条件较为不利;污染物浓度容易累积升高;高温、强光照有利于前体物的光化学反应迅速生成臭氧,进而推高臭氧浓度。15~30日江门市除了VOCs本地发生光化学反应生成臭氧外,也有受不同程度的外来传输影响。污染期间江门市主要特征物种有来源植物排放的2-甲基1,3-丁二烯,工业工艺源、溶剂涂料使用行业相关的甲苯、间对二甲苯、邻二甲苯,工业和机动车排放的乙烯,也包括油气挥发相关的低碳类烷烃等。建议加强江门与上风向地区的VOCs管控,以减轻秋季珠三角西南部的臭氧污染水平。

From September 14 to 30,2019,there was a heavy ozone pollution process in Jiangmen City,including four days of mild pollution,six days of moderate pollution and five days of severe pollution.The main causes of pollution were that the atmospheric diffusion conditions were unfavorable due to the control of subtropical high and the weather conditions outside the typhoon.The concentration of pollutants was easy to accumulate and rise.High temperature and strong light were conducive to the photochemical reaction of precursors to quickly generate ozone,and then pushed up the ozone concentration.From 15th to 30th,in addition to the photochemical reaction of VOCs to generate ozone,Jiangmen City was also affected by different degrees of external transmission.During the pollution period,the main characteristic species in Jiangmen City included 2-methyl 1,3-butadiene emitted from plants,toluene,m-p-xylene and o-xylene related to industrial process sources,solvent and coating use industries,ethylene emitted by industries and motor vehicles,as well as low-carbon alkanes related to oil and gas volatilization.It was suggested to strengthen VOCs control in Jiangmen and upwind areas to reduce the ozone pollution level in the southwest of the Pearl River Delta in autumn.