哈尔滨市大气PM_(2.5)中多环芳香烃污染特征及来源解析

Pollution characteristics and source apportionment of polycyclic aromatic hydrocarbons in PM_(2.5) in Harbin City

本文旨在分析哈尔滨市两城区(道里区和香坊区)2014年—2019年PM_(2.5)中16种芳香烃质量浓度变化规律,明确芳香烃中主要的污染及来源.将颗粒物中的多环芳香烃收集于滤膜,滤膜用乙醚/正己烷的混合溶剂提取,提取液经过浓缩、净化后,用具有荧光及紫外检测器的高效液相色谱仪分离检测.通过空气污染人群健康检测系统选取与PM_(2.5)监测期相同时期的平均气压、平均温度、平均相对湿度、降水量、日照小时数、平均风速等6种气象因素数据,采用Spearman法分析6种气象因素与16种多环芳香烃的相关性.结果表明,道里区PM_(2.5)平均质量浓度为84.9μg·m^(-3),香坊区为86.5μg·m^(-3).两城区的PM_(2.5)与平均气压呈显著正相关,与平均温度、平均相对湿度、降水量、日照小时数呈显著负相关.道里区和香坊区在2014—2019年多环芳香烃平均质量浓度分别为50.7 ng·m^(-3)、59.5 ng·m^(-3).其贡献值由高到低为芘>荧蒽>䓛>苯并[a]蒽>苯并[b]荧蒽>苯并[a]芘>苯并[k]荧蒽>苯并[g,h,i]苝>茚并[1,2,3-c,d]芘>菲>二苯并[a,h]蒽>蒽>苊烯>茐>萘>苊.气象因素中日照小时数、平均风速和降水量与多环芳香烃有显著相关性.哈尔滨市道里区和香坊区多环芳香烃中芘、荧蒽、䓛、苯并[a]蒽、苯并[b]荧蒽、苯并[k]荧蒽、苯并[a]芘、茚并[1,2,3-c,d]芘为主要成分.主成分分析结果表明,哈尔滨市大气中多环芳香烃的主要来源可能为冬季供暖期的煤炭燃烧及生物质燃烧、汽车尾气及工业排放,应加强对其主要污染来源的监测和污染控制,以减少哈尔滨市大气PM_(2.5)中多环芳香烃污染对健康的危害.

To obtain the mass concentrations change and main sources of polycyclic aromatic hydrocarbons(PAHs),16 kinds of PAHs in PM_(2.5)from two districts(Daoli district and Xiangfang district)were analyzed during 2014 to 2019 in Harbin city.PAHs in PM_(2.5)were collected in the filter membrane and extracted with ether/n-hexane mixed solvent.After concentration and purification,the extract was separated and detected by high performance liquid chromatography with fluorescence and ultraviolet detector.Six meteorological factors including mean air pressure,mean temperature,mean relative humidity,precipitation,illumination and mean wind speed during the PM_(2.5)monitoring period were provided by the information system of air pollution health impact monitoring.Spearman method was used to analyze the correlation between six meteorological factors and 16 kinds of PAHs.The results showed that the average mass concentration was 84.9μg·m^(−3)in Daoli district and 86.5μg·m^(−3)in Xiangfang district.The mass concentrations of PM_(2.5)in two districts were positively correlated with average air pressure,and negatively correlated with average temperature,average relative humidity,precipitation and illumination.The average concentrations of PAHs were 50.7 ng·m^(−3)and 59.5 ng·m^(−3)in Daoli district and Xiangfang district from 2014 to 2019,respectively.The contribution rates ranked as pyrene>fluoranthene>chrysere>benzo[a]anthracene>benzo[b]fluoranthene>benzo[a]pyrene>benzo[k]fluoranthene>benzo[g,h,i]perylene>indeno[1,2,3-c,d]pyrene>phenanthrene>dibenzo[a,h]anthracene>acenaphthene>fluorene>naphthalene>acenaphthene.The meteorological factors of illumination,daily average wind speed and precipitation were significantly correlated with PAHs.Eight kinds of PAHs pyrene,fluoranthene,chrysere,benzo[a]anthracene,benzo[b]fluoranthene,benzo[k]fluoranthene,benzo[a]pyrene,indeno[1,2,3-c,d]pyrene were main components in two districts of Harbin city.Principal component analysis results indicated that the main sources of PAHs in the atmosphere of Harbin City may be due to coal combustion during the heating period,automobile exhaust and industrial emission.The monitoring of the main pollution sources should be strengthened to reduce the health risk caused by PAHs in PM_(2.5)in Harbin city.