沙尘天气对兰州市PM_(10)中主要水溶性离子的影响  

Effect of Sand Dust Weather on Major Water-soluble Ions in PM_(10) in Lanzhou,China

作　　者：王芳[1,2] 陈强 张文煜[1] 郭勇涛[1] 赵连彪[3] 

机构地区：[1]兰州大学大气科学学院,半干旱气候变化教育部重点实验室,兰州730000 [2]德州学院化学化工学院,德州253023 [3]西北民族大学化工学院,兰州730030

出　　处：《环境科学》2014年第7期2477-2482,共6页Environmental Science

基　　金：甘肃省科技攻关项目(1204FKCA130);半干旱气候变化教育部重点实验室(兰州大学)开放课题项目

摘　　要：利用在线监测仪器MARGA在兰州大学盘旋路校区对兰州市大气PM10中水溶性离子进行监测,监测期间（2011-04-01-2011-06-30）有15 d出现沙尘天气.兰州市PM10中主要水溶性离子物种为Ca^2＋、SO4^2-和NO3^-.扬沙天气期间NO3^-和NH4^＋的浓度比非沙尘期间低,说明沙尘天气对当地人为源所排放污染物具有清除作用.沙尘天气期间,作为土壤污染源标识物的Mg^2＋、Na^＋和Ca^2＋离子都有明显增加,Na^＋和Mg^2＋相关系数为0.520,Na^＋和Ca^2＋相关系数为0.659,Mg^2＋和Ca^2＋相关系数为0.671,而非沙尘天气期间三者的相关系数并不高,Na^＋和Mg^2＋相关系数为0.065,Na^＋和Ca^2＋相关系数为0.131,Mg^2＋和Ca^2＋相关系数为0.163,说明沙尘天气期间三者之间具有相同的污染源,主要来自于土壤风沙尘,而非沙尘天气期间三者来源不同.Cl^-的浓度在扬沙天气明显高于浮尘和非沙尘天气期间,说明外来的土壤风沙尘是Cl^-的主要来源.The major water-soluble ions（ Ca^2 ＋,NH4^＋,Mg^2 ＋,K^＋,Na^＋,SO4^2-,NO3^-and Cl^-） in PM10at 1-h interval were measured by an online analyzer for monitoring of Aerosols and Gases（ MARGA） at the campus of Lanzhou University,from April 1 to June 30,2011. There were 15 days of dust weather during the monitoring period. The main water-soluble ions in PM10were Ca^2 ＋,SO4^2-and NO3^-. The concentration of NO3^-and NH4^＋decreased during blowing sand weather comparing with non-dust,this phenomenon showed that the dust weather had the function of eliminating the local anthropogenic emissions. As the soil pollution marker,the concentration of Mg^2 ＋,Na^＋and Ca^2 ＋increased during dust weather comparing with non-dust. The correlation coefficients between Na^＋and Mg^2 ＋,Na^＋and Ca^2 ＋,Mg^2 ＋and Ca^2 ＋during dust weather were 0. 520,0. 659 and 0. 671,respectively. The similar correlation coefficients indicated that some fraction of these species was derived from the same sources,such as soil dust. The correlation coefficients between Na＋and Mg^2 ＋,Na＋and Ca^2 ＋,Mg^2 ＋and Ca^2 ＋during non-dust weather were not strong,only 0. 065,0. 131 and 0. 163,respectively. The low correlation coefficients indicated that these species were derived from different sources. The mass concentration of Cl^-in the dust weather was significantly higher than that of floating dust and non dust,indicating that soil dust was the main source of Cl^-.

关 键 词：PM10 水溶性离子 化学特征 沙尘天气 在线监测 

分 类 号：X513[环境科学与工程—环境工程]