西宁市PM2.5水溶性无机离子特征及其来源解析  

Characteristics and Source Apportionment of Water-Soluble Inorganic Ions in PM2. 5 in Xining City

作　　者：胡晓峰 张翔[2] 柳笑[2] 张晓晶 修光利 王虹[2] 王建荣[3] HU Xiaofeng;ZHANG Xiang;LIU Xiao;ZHANG Xiaojing;XIU Guangli;WANG Hong;WANG Jianrong(State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Processes,School of Resources & Environmental Engineering,East China University of Science and Technology,Shanghai 200237,China;School of Chemical Engineering,Qinghai University,Xining 810016,China;Qinghai Research and Design Institute of Environmental Sciences,Xining 810007,China)

机构地区：[1]华东理工大学资源与环境工程学院,国家环境保护化工过程环境风险评价与控制重点实验室,上海200237 [2]青海大学化工学院,青海西宁810016 [3]青海省环境科学研究设计院,青海西宁810007

出　　处：《环境科学研究》2019年第7期1179-1186,共8页Research of Environmental Sciences

基　　金：青海省自然科学基金项目(No.2017-ZJ-789);国家自然科学基金项目(No.U1507122)~~

摘　　要：为探讨西宁市PM2.5水溶性无机离子的特征及其来源,于2017年1月—2018年4月在西宁市开展PM2.5样品采集工作,使用离子色谱仪分析水溶性无机离子.结果表明:西宁市大气中ρ(PM2.5)平均值为(42.7±36.6)μgm^3,4个采样点ρ(PM2.5)大小顺序依次为市区(54.9μgm^3)>工业区(44.1μgm^3)>郊区(40.8μgm^3)>农村(28.3μgm^3);ρ(PM2.5)季节性分布特征明显,呈冬季最高、夏季最低的特征.SNA(为SO42-、NO3-和NH4+的统称)是最主要的水溶性离子,占总水溶性离子的66.3%,SNA季节性分布特征为冬季最高、夏季最低.4个采样点SOR(硫氧化率)和NOR(氮氧化率)平均值均大于0.10,说明SO4^2-和NO3^-主要来源于二次转化.采样期间PM2.5中ρ(NO3^-)ρ(SO4^2-)为0.72,表明燃煤源排放大于交通源排放.主成分分析显示,西宁市PM2.5水溶性离子来源主要为二次粒子源、工业源、扬尘源和燃烧源.研究显示,西宁市城区、工业区、郊区大气中ρ(PM2.5)平均值均超过GB3095—2012《环境空气质量标准》一级标准限值,建议减少PM2.5的产生应以控制二次粒子源、工业源、燃烧源和扬尘源为主.To study the characteristics and source of water-soluble inorganic ions in PM 2.5 in Xining City,China,PM 2.5 samples were collected from January 2017 to April 2018,and the water-soluble inorganic ions in PM 2.5 were determined by ion chromatography.The results show the following:The daily mean concentration of PM 2.5 was(42.7±36.6)μg m 3 in Xining City,with the concentration of PM 2.5 distributed regionally following a descending sequence of urbans(54.9μg m^3)>industrial areas(44.1μg m 3)>suburbs(40.8μg m^3)>country(28.3μg m^3).Seasonal distribution characteristics of PM 2.5 were obvious:The highest mass concentrations of PM 2.5 were observed in winter and the lowest in summer;SNA(sulfate,nitrate and ammonium)comprised the main water-soluble ions,totaling 66.3%of the total ions,and regarding the seasonal distribution characteristics of SNA,the highest mass concentrations of PM 2.5 were observed in winter and the lowest in summer.The mean annual sulfur oxidation ratio(SOR)and nitrogen oxidation ratio(NOR)values of the four regions were all higher than 0.10,indicating that SO 4^2-and NO 3^-were mainly converted from secondary transformation.Theρ(NO 3^-)ρ(SO 4^2-)ratio of PM 2.5 was 0.72,demonstrating that emissions from coal combustion were greater than those from transportation emissions.The results of the principal component analysis indicate that the water-soluble ions of PM 2.5 in Xining City are mainly derived from secondary particles,industrial sources,re-suspended dust and biomass burning.The research shows that the air quality of urban,industrial and suburban areas in Xining City exceeded the levelⅠ24 h limit values of Ambient Air Quality Standard(GB 3095-2012).It is recommended that PM 2.5 should be reduced by controlling the secondary transformation,industrial sources,biomass burning and re-suspended dust.

关 键 词：西宁市 水溶性无机离子 SNA 来源解析 

分 类 号：X51[环境科学与工程—环境工程]