2016-2020年辽西四城市PM_(2.5)和O_(3)污染特征对比分析

Comparative Analysis of PM_(2.5) and O_(3) Pollution Characteristics in Four Cities of Western Liaoning from 2016 to 2020

文章利用2016-2020年辽宁西部沿海的锦州、葫芦岛和内陆的阜新、朝阳空气质量监测数据,对比分析4个城市PM_(2.5)污染、O_(3)污染以及二者复合污染演变特征和异同性。结果表明:(1)4个城市PM_(2.5)年均浓度均呈下降趋势,沿海两市PM_(2.5)污染重于内陆两市;(2)沿海两市O_(3)污染减轻,内陆两市O_(3)加重且2018年后年评价浓度高于沿海;(3)4个城市易出现同步污染过程,沿海两市的污染过程同步性更高且持续时间更长;(4)沿海城市“PM_(2.5)-O_(3)”复合污染天多于内陆城市,城市间同步复合污染范围逐年扩大;(5)4个城市PM_(2.5)与NO_(2)、CO和SO_(2)等污染物均呈正相关,沿海城市与CO的相关性好,内陆城市与NO_(2)相关性好,O_(3)与前体物NO_(2)和CO均呈负相关,与NO_(2)的相关性好于CO。研究表明,辽西4城市PM_(2.5)和O_(3)污染形势仍不乐观,区域污染和复合污染问题显现,PM_(2.5)和O_(3)协同治理和区域联防联控对改善空气质量具有重要意义,在城市和区域大气污染防治工作中应给予重视。

The data from 2016 to 2020 released by China National Environmental Monitoring Centre(CNEMC)of Jinzhou,Fuxin,Chaoyang and Huludao which located in the western of Liaoning Province were used to investigate the characteristics of the pollution of PM_(2.5),O_(3)and“PM_(2.5)-O_(3)”compound pollution in order to explore the pollution trends,similarities and differences among these cities.Jinzhou and Huludao are coastal cities,Fuxin and Chaoyang are inland cities.The results showed that:(1)The annual concentration of PM_(2.5)in these four cities showed a downward trend,besides,the values in coastal cities were higher than those in inland cities.(2)The 90th percentile concentrations of O_(3)-8 h of coastal cities decreased,meanwhile the concentrations of inland cities increased and surpassed that of coastal cities since 2018.(3)The four cities were prone to synchronous pollution processes,and the pollution processes of the two coastal cities were more synchronous and lasted longer.(4)The“PM_(2.5)-O_(3)”compound pollution days in coastal cities were more than those in inland cities,the scope of synchronous pollution of the four cities expanded year by year and the number of cities with simultaneous pollution increased.(5)PM_(2.5)was positively correlated with NO_(2),CO and SO_(2)in these four cities with the best correlation with CO in coastal cities and with NO_(2)in inland cities.O_(3)was negatively correlated with NO_(2)and CO,and the correlation with NO_(2)was strong than that with CO.Therefore,the studies indicated that the situation of pollution of PM_(2.5)and O_(3)is still not optimistic in western Liaoning Province,and the problems of regional pollution and compound pollution are gradually emerging.The coordinated control,regional joint prevention and control strategies of PM_(2.5)and O_(3)are of great significance to improve air quality and should be paid more attention for urban and regional air pollution prevention and control.