摘要
为探究新乡市大气PM_(2.5)中水溶性无机离子(WSIIs)的污染演变、来源特征及其气象影响,利用URG-9000在线监测系统于2022年1月(冬季)、4月(春季)、7月(夏季)和10月(秋季)对PM_(2.5)组分进行在线观测.结果表明,TWSIIs(总水溶性无机离子)与PM_(2.5)的季节变化特征一致,季度ρ(TWSIIs)均值变化范围为19.62~72.15μg·m^(-3),在PM_(2.5)中的占比超过66%,WSIIs是大气PM_(2.5)的重要组分.年均NO_(3)^(-)/SO_(4)^(2-)(质量浓度比)为2.11,且呈现逐年增加的趋势,移动源对二次无机气溶胶(SNA)的影响不容忽视,年均[NH_(4)^(+)]/[NO_(3)^(-)](量比)为1.95,说明农业源是大气中氮的主要贡献者.后向轨迹分析表明,在盛行东北风且风速较大时,PM_(2.5)中Ca^(2+)和Mg^(2+)的浓度较高.低温高湿的气象条件下(T<8℃,RH>60%),SOR和NOR值均较高,更多的气态前体物SO_(2)和NO_(2)转化为颗粒态的SO_(4)^(2-)和NO_(3)^(-).与SOR不同,在高温条件下(T>24℃),NOR并没有表现出高值特征,与高温条件下NH_(4)NO_(3)的分解有关.结合PMF和后向轨迹分析,来自西北方向的气团所对应的扬尘源对WSIIs的贡献较大,观测站点周边区域的低空低速气团所对应的二次硫酸盐以及二次硝酸盐和生物质源对WSIIs的贡献较大.
Pollution variation,source characteristics,and meteorological effects of water-soluble inorganic ions(WSIIs)in PM_(2.5) were analyzed in Xinxiang city,Henan Province.PM_(2.5) samples and their chemical components were monitored online by using URG-9000 in four seasons:winter(January,2022),spring(April,2022),summer(July,2022),and fall(October,2022).The results showed that the TWSIIs had the same seasonal fluctuations as PM_(2.5).The average seasonal concentrations of WSIIs ranged from 19.62-72.15μg·m^(−3),accounting for more than 60%of PM_(2.5),demonstrating that WSIIs were the major components of PM_(2.5).The annual concentration value of NO_(3)^(-)/SO_(4)^(2-) was 2.11,which showed an increasing trend,suggesting predominantly mobile sources for secondary inorganic aerosols(SNA).Further,the molar concentration value [NH_(4)^(+)]/[NO_(3)^(-)] was 1.95,demonstrating that agriculture emissions were the dominant contributors to atmospheric nitrogen.Furthermore,the backward trajectory analysis showed that the concentrations of Ca^(2+)and Mg^(2+)were higher when the northeasterly wind prevailed and the wind speed was high.High values of SOR and NOR were correlated with low temperatures and high relative humidity(T<8℃,RH>60%),demonstrating that more gaseous precursors were converted into sulfate and nitrate.At high temperatures(T>24℃),there was no apparent high NOR value like that for SOR,mainly due to the decomposition of NH_(4)NO_(3) at high temperatures.Finally,backward trajectories associated with the PMF-resolved results were used to explore the regional transport characteristics.The results illustrated that dust sources in the study areas were mainly influenced by air trajectories originating from the northwest regions,whereas secondary sulfate,secondary nitrate,and biomass sources contributed more to WSIIs when wind speed and altitude air masses were low in the area surrounding the observation site.
作者
刘桓嘉
李岚清
李焕莉
任言
许梦源
贾梦珂
刘恒志
杨莹
宋天颂
洪启航
LIU Huan-jia;LI Lan-qing;LI Huan-li;REN Yan;XU Meng-yuan;JIA Meng-ke;LIU Heng-zhi;YANG Ying;SONG Tian-song;HONG Qi-hang(Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control,Ministry of Education,Henan Key Laboratory for Environmental Pollution Control,School of Environment,Henan Normal University,Xinxiang 453007,China;Xin'an Branch of Luoyang Ecological Environment Bureau,Luoyang 471800,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2024年第3期1349-1360,共12页
Environmental Science
基金
国家自然科学基金项目(42007204)
河南省科技攻关项目(222102320394)
河南省博士后科研项目(HN2022023)。
关键词
PM_(2.5)
水溶性无机离子
污染特征
来源解析
气象要素
新乡
PM_(2.5)
water-soluble inorganic ions
pollution characteristics
source apportionment
meteorological factors
Xinxiang
