山东淄博夏季大气PAN污染特征及影响因素分析  

Analysis of the characteristics and influencing factors of atmospheric PAN pollution in summer in Zibo,Shandong Province

作　　者：蔡浩晨 覃泽 徐勃 刘盈盈 王晓丽[1] 杨文[2] 耿春梅[2] CAI Haochen;QIN Ze;XU Bo;LIU Yingying;WANG Xiaoli;YANG Wen;GENG Chunmei(College of Environmental Science&Safety Engineering,Tianjin University of Techology,Tianjin 300384;State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012;Shandong Zibo Ecological Environment Monitoring Center,Zibo 255000)

机构地区：[1]天津理工大学环境科学与安全工程学院,天津300384 [2]中国环境科学研究院环境基准与风险评估国家重点实验室,北京100012 [3]山东省淄博生态环境监测中心,淄博255000

出　　处：《环境科学学报》2024年第12期229-239,共11页Acta Scientiae Circumstantiae

基　　金：大气重污染成因与治理攻关项目(No.DQGG202119,DQGG202137)。

摘　　要：为深入认识城市夏季频发的光化学污染现象,于2022年(6月1—30日)在山东省淄博市对典型的光化学污染物过氧乙酰硝酸酯(PAN)进行连续观测,探讨夏季大气PAN污染状况及影响因素,估算前体物过氧乙酰自由基(PA),并结合广义相加模型(GAM)分析前体物及气象因素对PAN的影响.结果表明,研究期间PAN的平均浓度为1.60×10^(-9),最大值为5.31×10^(-9),高于同时期北京、天津等较多监测站点,其日变化特征呈单峰形特征,PAN和O_(3)的浓度与温度和光解速率(J_(NO_(2)))日变化一致,与TVOC、NO_(2)和湿度相反.相关性分析表明污染和非污染时期PAN和O_(3)线性拟合的R^(2)分别为0.30和0.21,较低的R^(2)可能是由PAN和O_(3)的前体物差异所引起的.对PA自由基浓度进行估算,其日均值体积分数为0.01×10^(-12)~0.61×10^(-12),表明研究区域光化学反应强烈.GAM模型多因素拟合结果表明PAN浓度受O_(x)、J_(NO_(2))和前体物影响最大,而当温度>28℃,湿度>60%时,PAN浓度与温度和湿度呈非线性负相关.本研究加深了对O_(3)污染背景条件下华北平原城市地区PAN污染特征及影响因素的理解,以期为改善城市大气光化学污染提供科学依据.To gain a deeper understanding of the frequent photochemical pollution in urban areas during summer,continuous observation of the typical photochemical tracer,peroxyacetyl nitrate(PAN),was conducted in Zibo City,Shandong Province,from June 1 to June 30,2022.This study investigates the characteristics and influencing factors of tropospheric PAN pollution in summer,estimates the concentration of its precursor peroxyacetyl radicals(PA),and analyzes the impact of its precursors and multiple meteorological factors on the concentration of PAN using the generalized additive model(GAM).The results showed that during the study period,the average concentration of PAN was 1.60×10^(-9),with a maximum value of 5.31×10^(-9),which was higher than that observed at many sites including Beijing and Tianjin during the same period.The diurnal variation of PAN exhibited a single-peak pattern.The diurnal variations of PAN and O_(3) were consistent with temperature and photolysis rate of NO_(2)(J_(NO_(2))),and were opposite to those of TVOC,NO_(2),and humidity.The R^(2) values of the linear fit between PAN and O_(3) during polluted and non-polluted periods were 0.30 and 0.21,respectively.The relatively low R^(2) values may result from differences in the precursors of PAN and O_(3).The estimated daily average volume fraction of PA radicals ranged from 0.01×10^(-12)to 0.61×10^(-12),indicating strong photochemical reactivity in the study area.The multi-factor fitting results of the GAM model revealed that PAN concentrations were primarily influenced by O_(x),J_(NO_(2)),and precursors.A nonlinear negative correlation between PAN concentration and temperature and humidity were found when the temperature was above 28℃and humidity exceeded 60%.This study enhances the understanding of the characteristics and influencing factors of PAN pollution in urban areas of the North China Plain under the background of O_(3) pollution,providing a scientific basis for mitigating urban air pollution.

关 键 词：过氧乙酰硝酸酯(PAN) PA自由基 光化学污染 气象因素 广义相加模型 

分 类 号：X51[环境科学与工程—环境工程]