2019~2022年华北平原典型地区不同污染等级和污染持续时间下的O_(3)污染规律及来源  

Characteristics and sources of O_(3) pollution under different pollution levels and durations in typical areas of North China Plain from 2019 to 2022

作　　者：钱昱先 王刚[1] 孟庆晓 刘赛[1] 王永强[1] QIAN Yu-xian;WANG Gang;MENG Qing-xiao;LIU Sai;WANG Yong-qiang(College of Chemistry and Chemical Engineering,China University of Petroleum(East China),Qingdao 266580,China;Juxian Branch of Rizhao Municipal Bureau of Ecology and Environment,Rizhao 276599,China)

机构地区：[1]中国石油大学(华东)化学化工学院,山东青岛266580 [2]日照市生态环境局莒县分局,山东日照276599

出　　处：《中国环境科学》2024年第7期3581-3591,共11页China Environmental Science

基　　金：莒县环境空气质量提升服务项目(HX20230979)。

摘　　要：选取地势复杂的日照市莒县为研究区域,基于2019~2022年莒县省控站点的O_(3)监测数据,按照不同O_(3)污染等级与不同O_(3)污染持续时间对莒县的O_(3)污染天进行分类,探究其污染规律,并采用后向轨迹模型(HYSPLIT)、潜在源分析(PSCF)和浓度权重轨迹分析法(CWT)识别不同O_(3)污染事件下的O_(3)来源.结果显示:2019~2021年莒县O_(3)轻度污染天数由72d下降到38d,2022年反弹,而中度污染天数变化不大;轻微污染天在轻度污染天中占比较高(21.4%~39.5%),表明轻度污染天的改善空间很大,强化轻微污染天管控措施,将有利于将轻度污染天转化为优良天,提高当地空气质量优良率.O_(3)污染过程持续时间越长(如≥3d),污染发生的频率越低,而O_(3)浓度随污染持续时间的增加而升高.HYSPLIT模拟结果显示不同O_(3)污染等级和不同O_(3)污染持续时间的气团轨迹均以莒县东南方向为主,且以中、短距离传输为主,其中中度污染期间来自东南地区的O_(3)-8h-90%浓度最高[(250.0±65.9)µg/m^(3)].PSCF和CWT结果显示,O_(3)潜在源区主要分布在莒县东南方向,长江三角洲地区是莒县O_(3)污染的主要的潜在源区.研究结果对于指导莒县及周边区域的大气污染联防联控具有重要意义.This study selects Juxian,Rizhao with complex terrain as the research area.Based on O_(3) monitoring data from provincial control stations in Juxian from 2019 to 2022,the O_(3) pollution days were classified according to different O_(3) pollution levels and durations.The pollution characteristics and sources of O_(3) were explored using backward trajectory model(HYSPLIT),potential source contribution function(PSCF),and concentration weighted trajectory(CWT)models.Results showed that the number of mild pollution days of O_(3) in Juxian decreased from 72 to 38 during the period of 2019 to 2021,while rebounded in 2022.The number of moderate pollution days of O_(3) have little change.Slight pollution days of O_(3) accounted for a high proportion of mild pollution days,with the contribution of 21.4%~39.5%,indicating a great potential for improvement for mild pollution days.Strengthening the control measures for slight pollution days will be beneficial for converting mild pollution days into excellent days and improving the local air quality excellence rate.The longer the duration of O_(3) pollution(e.g.,≥3d),the lower the frequency of pollution occurrence,while the O_(3) concentration increased with the extend of pollution duration.Simulation results of the HYSPLIT model revealed that the air mass trajectories of different O_(3) pollution levels and durations were mainly distributed in the southeast of Juxian and transmitted over medium and short-distances.Besides,trajectories from the southeast of Juxian contained the highest concentration of O_(3)-8h-90%(250.0±65.9µg/m^(3)).The PSCF and CWT results showed that the potential source regions of O_(3) were mainly distributed in the southeast of Juxian,with the main potential source region appearing in the Yangtze River Delta region.The results are of great significance for guiding the joint prevention and control of air pollution in Juxian and surrounding areas.

关 键 词：臭氧 污染等级 污染持续时间 后向轨迹 潜在源区 

分 类 号：X511[环境科学与工程—环境工程]