北京市PM_(2.5)主要化学组分浓度水平研究与特征分析  

Characteristics and major chemical compositions of PM_(2.5) in Beijing

作　　者：刘保献[1,2] 张大伟[1,2] 陈添[3] 杨懂艳[1,2] 杨柳[1,2] 常淼[1,2] 林安国[1,2] 

机构地区：[1]北京市环境保护监测中心,北京100048 [2]大气颗粒物监测技术北京市重点实验室,北京100048 [3]北京市环境保护局,北京100048

出　　处：《环境科学学报》2015年第12期4053-4060,共8页Acta Scientiae Circumstantiae

基　　金：北京市科技计划(No.Z121100000312035);环保公益性行业科研专项(No.201409005)~~

摘　　要：为研究北京市大气环境PM_(2.5)中主要化学组分特征,于2012年8月—2013年7月期间,在北京市定陵、车公庄、东四、石景山、通州、房山、亦庄和榆垡等8个点位开展为期1年的样品采集,共计采集472组样品,分析每组样品中OC、EC、水溶性离子和18种无机元素等组分.研究结果表明,本次研究的组分重建后和实际PM_(2.5)浓度相关性显著,相关系数为0.94,所测组分平均占PM_(2.5)总量的90%;各点位不同季节PM_(2.5)中主要的组分均为OC、NO_3^-、SO_4^(2-)、NH_4^+,呈南高北低的趋势,冬季OC是夏季的1.7倍,NO_3^-和SO2--4在四季呈交替状态,除榆垡点位的SO_4^(2-)>NO_3^-外,其他点位均是NO_3^->SO_4^(2-),4种主要的组分质量浓度分别为(23.1±21.4)、(20.3±23.4)、(19.4±22.2)、(13.6±15.2)μg·m-3,占PM_(2.5)总含量的18.5%、16.3%、15.6%、10.9%;研究水溶性离子发现,8个点位全年SNA/PM_(2.5)比例为42.8%,其中,夏季最高(49.9%),秋季较低(31.1%),NO_3^-/SO_4^(2-)比值平均为1.05,相对往年研究结果 NO_3^-/SO_4^(2-)比值有增加的趋势.In order to understand the major chemical composition of PM2.5 in Beijing, 472 groups of PM2.5 samples were collected from July 2012 to August 2013 at 8 sites, including Dingling, Chegongzhuang, Shijingshan, Dongsi, Tongzhou, Liangxiang, Yizhuang, and Yufa. The water-soluble ions, organic and elemental carbon, and 18 types of inorganic elements of samples were analyzed. The reconstructed chemical composition was compared with the mass concentration of PM2.5 , with a correlation coefficient of 0.94. The measured components accounted for about 90% of the total mass of PM2.5. The major chemical species in PM2.s were OC, NO-3, SO24-, and NH＋4, with a concentration of （23.1±21.4） , （20.3±23.4） , （19.4±22.2） , and （ 13.6± 15.2） μg.m-3, accounting for 18.5%, 16.3%, 15.6%, and 10.9% in PM2.5, respectively. The concentrations of major chemical species in PM2.5 increased gradually from North to South. The OC in winter was 1.7 times that in summer, and the concentration of NO3 is higher than SO2- in most of the sites except Yufa with seasonal variations. The SNA/PM2.5 ratio ranged from 31.1% （autumn） to 49.9% （summer） , with the annual average of 42.8%. The average ratio of NO3/SO3- was 1.05, higher than the previous values.

关 键 词：PM2.5 化学组分特征 OC/EC 水溶性离子 

分 类 号：X131.1[环境科学与工程—环境科学] X513