云贵高原城市PM_(2.5)中水溶性离子的污染特征  

Pollution Characteristic of Water-soluble Ions in PM_(2.5) in Cities of Yunnan-Guizhou Plateau

作　　者：张勇 陈卓[3] 董娴[3] 保玉心 杨明 ZHANG Yong;CHEN Zhuo;DONG Xia;BAO Yuxin;YANG Ming(Analytical and Testing Center,Zunyi Medical University,Zunyi 563000,China;Research Center for Physical and Chemical Analysis and Testing Engineering Technology,Zunyi 563000,China;College of Chemistry and Material Science,Guizhou Normal University,Guiyang 550001,China)

机构地区：[1]遵义医科大学分析测试中心,贵州遵义563000 [2]遵义市理化分析测试工程技术研究中心,贵州遵义563000 [3]贵州师范大学化学与材料科学学院,贵州贵阳550001

出　　处：《环境科学与技术》2023年第4期100-109,共10页Environmental Science & Technology

基　　金：国家自然科学基金项目(21767007);遵义市科技计划项目(遵市科合社字(2017)10号);遵义医科大学硕士启动资金(F-901)。

摘　　要：为探究云贵高原区域城市PM_(2.5)中水溶性离子的污染特征及来源,该文选取贵阳市和遵义市作为典型城市进行PM_(2.5)样品采集,分析样品中8种水溶性无机离子(WSIIs)的污染特征,并采用主成分-多元线性回归法(PCA-MLR)解析其来源。结果表明,研究期间贵阳市和遵义市WSIIs浓度均值分别为22.64、14.44μg/m^(3),呈夏季最低、冬季最高的季节变化特征。2个站点氮氧化率(NOR)平均值分别为0.15、0.12,说明NO_(3)-二次转化不明显,且夏季NOR的值远小于0.1,表明研究区域夏季NO_(3)-来自于一次源。硫氧化率(SOR)平均值分别为0.44、0.35,表明SO_(4)^(2-)主要由二次反应形成。阴阳离子平衡分析表明,贵阳市春、夏、秋3个季节的PM_(2.5)呈碱性,冬季PM_(2.5)呈弱酸性,而遵义市全年PM_(2.5)呈碱性,主要由SO_(4)^(2-)浓度差异导致。2个站点颗粒物中NH4+的存在形式相同,以(NH_(4))_(2)SO_(4)、NH_(4)NO_(3)形式存在。PCA-MLR分析表明,贵阳市和遵义市PM_(2.5)中WSIIs主要来源于二次源和燃煤,其贡献率冬季占比最高。遵义市各季节WSIIs还受到生物质燃烧的影响。In order to explore the pollution characteristics and sources of water soluble ions in PM_(2.5)in the cities of Yunnan-Guizhou Plateau region,Guiyang and Zunyi were selected as the typical cities for the study object,wherein PM_(2.5)sampling was conducted respectively at two cities'monitoring sites,and in the PM_(2.5) samples,eight kinds of water soluble inorganic ions(WSIIs)were analyzed in terms of their pollution characteristics,then the principal component analysis-multiple linear regression(PCA-MLR)method was performed aiming at WSIIs sources apportionment.Results of the exploration showed that the annual average concentration of WSIIs of Guiyang and Zunyi were 22.64μg/m^(3)and 14.44μg/m^(3),respectively;besides,WSIIs concentration changed seasonally,with the minimum concentration in summer,and the maximum concentration in winter;the average nitrogen oxidation ratio(NOR)measured at two cities'monitoring sites were 0.15 and 0.12,respectively,indicating that the secondary conversion of NO_(3)-was not observable,and the value of NOR in summer was less than 0.1,which indicated that NO_(3)was derived from primary source in the study area in summer;on the other hand,average sulfur oxidation ratio(SOR)were 0.44 and 0.35,respectively,which suggested that SO_(4)^(2-)was mainly derived from the secondary reactions formation.Furthermore,analysis based on the charge balance demonstrated that the aerosol in Guiyang City was alkaline in spring,summer and autumn,and slightly acidic in winter,while in Zunyi City the annual PM_(2.5)over a whole year was alkaline,which was mainly due to the differences in SO_(4)^(2-)concentration;the forms of NH+existed in the PM sampled at the two cities monitoring sites were similar,i.e.,(NH_(4))_(2)SO_(4)、NH_(4)NO_(3).The analysis by PCA-MLR showed that the WSIIs in PM_(2.5)in Gui-yang and Zunyi mainly came from secondary sources and coal combustion,the highest contribution rate appeared in winter,while WSIIs of Zunyi in each season were affected by biomass burning as well.

关 键 词：水溶性离子 PM_(2.5) 污染特征 源解析 云贵高原 

分 类 号：X513[环境科学与工程—环境工程]