摘要
为探究浙江省城市大气颗粒物的组分污染特征,基于2019年10月1日至2020年9月30日浙江省内11个点位4个区域的手工采样监测数据,分析了浙江省PM_(2.5)组分不同区域不同季节的污染特征.结果表明,采样期内浙江省各地区ρ(PM_(2.5))平均值范围为34.3~46.4μg·m^(-3),其中浙西和浙北内陆地区PM_(2.5)浓度相对较高,分别高出均值15.1%和13.2%,浙东和浙南沿海地区PM_(2.5)浓度相对较低,分别低于均值8.4%和14.9%.季节性特征呈现秋季和冬季较高,夏季最低,空间分布来看,浙南地区的PM_(2.5)浓度春季、秋季和冬季季节变化不明显,浙西地区为:秋季>冬季>春季>夏季,浙北和浙东地区均呈现冬季>秋季>春季>夏季的季节变化特征.内陆地区采样期内,风景名胜区、行政区、居民区和商业交通居民混合区的ρ(PM_(2.5))分别为:(40.2±10.2)、(46.3±9.6)、(50.1±10.6)和(46.7±10.2)μg·m^(-3),居民区点位的PM_(2.5)污染水平均值最高.沿海地区采样期内,文化娱乐区和商业交通居民混合区的ρ(PM_(2.5))分别为:(27.4±5.8)μg·m^(-3)和(37.2±5.6)μg·m^(-3).采样期间浙江省PM_(2.5)组分中有机物(OM)、硝酸盐(NO_(3)^(-))、硫酸盐(SO_(4)^(2-))、铵盐(NH_(+)^(4))、微量元素和地壳物质贡献率分别为:26.4%、15.4%、12.4%、9.0%、7.1%和5.7%.二次无机气溶胶SNA(硫酸盐、硝酸盐和铵盐)贡献率达到36.8%.秋季、春季和夏季OM对PM_(2.5)的贡献高于其他组分,贡献率分别为28.3%、27.7%和26.3%,而冬季却表现为硝酸盐的贡献最为显著,贡献率达24.3%.空间分布上,SNA对各地区PM_(2.5)的贡献均最大,贡献率范围为32.8%~39.7%,浙北地区最高,浙南地区最低,各地区SNA,均呈现:硝酸盐>硫酸盐>铵盐.利用后向轨迹聚类分析发现,浙北地区秋季、冬季、春季和夏季主要气团来源分别为黄海江苏南部、安徽北部、东海和黄海江苏西部,贡献率分别为38.11%、35.28%、37.46%和27.87%.浙西地区秋季、冬季、春季和夏季分别受来自黄海江苏南部(38.11%)、安徽南部(37.50%)、浙江东部(46.55%)和浙北(32.58%)方向的气团影响.浙东地区秋季、冬季、春季和夏季则分别受来自河北北部(36.07%)、山东东部(38.06%)、东海(30.17%)和广东南部(34.43%)方向的气团影响.浙南地区秋季、冬季、春季和夏季分别受来自黄海(35.66%)、安徽东北部(34.44%)、东海(26.72%)和福建南部沿海(35.00%)方向的气团影响.浙江省各区域气团后向轨迹季节性差异较大,而各区域间ρ(PM_(2.5))西北最高值与东南最低之间的差值在秋季和冬季分别为21.0μg·m^(-3)和20.5μg·m^(-3),春季和夏季分别为10.4μg·m^(-3)和6.1μg·m^(-3),北方气团对浙江省秋季和冬季PM_(2.5)存在一定的外源性贡献,春季和夏季北方气团对浙江省气团轨迹的减弱,以及南方和东海海上气团对浙江省气流贡献的增大,PM_(2.5)质量浓度也存在好转的趋势.
To investigate the seasonal and regional pollution characteristics of PM_(2.5)chemical composition in Zhejiang province,this study was based on manual sampling monitoring data from 11 sampling sites of four regions in Zhejiang province from October 1,2019 to September 30,2020.The results showed that during the observation period,the averageρ(PM_(2.5))of the four regions ranged from 34.3μg·m^(-3)to 46.4μg·m^(-3).The PM_(2.5)mass concentrations in the hinterland areas of western Zhejiang and northern Zhejiang were relatively high,15.1%and 13.2%higher than the mean value,respectively.The PM_(2.5)mass concentrations in the coastal areas of eastern Zhejiang and southern Zhejiang were relatively low,8.4%and 14.9%lower than the average,respectively.The seasonal characteristics showed a higher concentration in autumn and winter and lowest concentration in summer.The seasonal variation in PM_(2.5)mass concentration from autumn to spring was not obvious in southern Zhejiang,whereas in western Zhejiang,the PM_(2.5)mass concentration followed a descending sequence of autumn>winter>spring>summer.In northern Zhejiang and eastern Zhejiang,the trend was winter>autumn>spring>summer.During the observation period in the inland area,theρ(PM_(2.5))of the scenic area,administrative area,residential area,and mixed area of commercial traffic and residents were(40.2±10.2),(46.3±9.6),(50.1±10.6),and(46.7±10.2)μg·m^(-3),respectively.The highest value ofρ(PM_(2.5))was in the residential area.During the sampling period in coastal areas,theρ(PM_(2.5))of the cultural and entertainment area and mixed area of commercial traffic and residents were(27.4±5.8)μg·m^(-3)and(37.2±5.6)μg·m^(-3),respectively.The contribution rates of organic matter(OM),NO_(3)^(-),SO_(4)^(2-),NH_(+)^(4),trace elements,and crustal matter in PM_(2.5)were 26.4%,15.4%,12.4%,9.0%,7.1%,and 5.7%,respectively.The SNA,including SO_(4)^(2-),NO_(3)^(-),and NH_(+)^(4),contributed 36.8%in PM_(2.5).In terms of seasons,the contribution of OM to PM_(2.5)in autumn,spring,and summer was higher than that of other compositions,which accounted for 28.3%,27.7%,and 26.3%,respectively.The contribution rate of NO_(3)^(-)in PM_(2.5)was the largest in winter,reaching 24.3%.In terms of spatial distribution,SNA contributed the most to PM_(2.5)in all regions,ranging from 32.8%to 39.7%,with the highest in northern Zhejiang and the lowest in southern Zhejiang.The SNA of all regions presented NO_(3)^(-)>SO_(4)^(2-)>NH_(+)^(4).Based on the backward trajectory clustering analysis,the main air sources of northern Zhejiang were the Yellow Sea-southern Jiangsu(autumn),northern Anhui(winter),East China Sea(spring),and western Jiangsu(summer)areas,with contribution rates of 38.11%,35.28%,37.46%,and 27.87%,respectively.The main air sources of western Zhejiang were the Yellow Sea-southern Jiangsu(autumn),southern Anhui(winter),eastern Zhejiang(spring),and northern Zhejiang(summer),with contribution rates of 38.11%,37.50%,46.55%,and 32.58%,respectively.The air of autumn,winter,spring,and summer in eastern Zhejiang were influenced by air masses from northern Hebei(36.07%),eastern Shandong(38.06%),East China Sea(30.17%),and southern Guangdong(34.43%),respectively.In autumn,winter,spring,and summer,southern Zhejiang was affected by air masses from the Yellow Sea(35.66%),northeast Anhui(34.44%),East China Sea(26.72%),and southern Fujian coast(35.00%),respectively.The regions in Zhejiang province showed large seasonal differences.The difference value between the maximum value ofρ(PM_(2.5))in the northwest and the lowest value in the southeast was 21.0μg·m^(-3)and 20.5μg·m^(-3)in autumn and winter,respectively;the difference values in spring and summer were 10.4μg·m^(-3)and 6.1μg·m^(-3).Thus,the northern air mass had a certain exogenous contribution to PM_(2.5)in autumn and winter in Zhejiang province.However,with the weakening of the northern air mass trajectory in spring and summer and the increasing contribution of the southern and east China Sea air mass to the air flow in Zhejiang province,PM_(2.5)pollution showed a trend of improvement.
作者
周菁清
余磊
陈书鑫
陆佳锋
许亚璐
季海冰
张柳芳
刘劲松
王静
ZHOU Jing-qing;YU Lei;CHEN Shu-xin;LU Jia-feng;XU Ya-lu;JI Hai-bing;ZHANG Liu-fang;LIU Jin-song;WANG Jing(Zhejiang Key Laboratory of Ecological and Environmental Monitoring,Forewarning and Quality Control,Zhejiang Ecological and Environmental Monitoring Center,Hangzhou 310012,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2023年第3期1297-1309,共13页
Environmental Science
基金
浙江省重点研发计划项目(2021C03176)
浙江省生态环境科研和成果推广项目(2021HT0019,2021HT0020,2021HT0005)。
关键词
浙江省
PM_(2.5)
化学组分
后向轨迹
聚类分析
Zhejiang province
PM_(2.5)
chemical composition
backward trajectory
cluster analysis
