摘要
采集了2017—2018年秋冬季长治市审计局站、监测站、清华站等3个监测站点的大气PM2.5样品,分析了其元素、水溶性离子及碳质组分特征,并利用化学质量平衡模型(CMB)对PM2.5进行来源解析.结果表明,采样期间长治市PM2.5浓度为67.9μg·m-3,其中审计局站PM2.5浓度最高(70.6μg·m-3),其次为监测站(70.0μg·m-3)和清华站(63.0μg·m-3);二次无机离子(SO42-、NO-3、NH+4)平均浓度(20.7μg·m-3)占PM2.5浓度的30.5%,与大量排放到大气中的SO2、NO2二次生成有关;OC(12.6μg·m-3)和EC(6.6μg·m-3)分别占PM2.5的18.6%和9.7%;OC/EC为2.06,且SOC(5.9μg·m-3)在OC中占比高达63.1%,表明长治市秋冬季二次污染较重;典型地壳元素Si和Ca占元素组分平均浓度的29.8%和22.8%,说明扬尘污染对长治市PM2.5的有一定影响;源解析结果表明,长治市秋冬季PM2.5主要来源为:机动车源17.0%、燃煤源16.5%、扬尘源14.6%、二次硝酸盐13.9%、二次硫酸盐11.0%、二次有机气溶胶10.8%、工艺过程源9.3%、生物质燃烧源1.9%、其他源5.0%.因此,为进一步降低长治市环境空气中PM2.5的污染,需在加强管控机动车,燃煤和扬尘等一次排放源的基础上,降低一次污染物SO2、NO2等的排放,从而实现对二次污染源前体物的控制.
Atmospheric PM2.5 samples were collected from three sites of Shenjiju site,Jiancezhan site and Qinghua site in Changzhi in autumn and winter of 2017—2018.The characteristics of trace elements,water-soluble ions and carbon components of PM2.5 were analyzed,and chemical mass balance model(CMB)was used to analyze the source of PM2.5.The results showed that the concentration of PM2.5 in Changzhi was 67.9μg·m-3 during the sampling period,the concentration of three sampling sites were decreasing followed by Shenjiju(70.6μg·m-3),Jiancezhan(70.0μg·m-3)and Qinghua(63.0μg·m-3).The average concentration of secondary inorganic ions(SO42-,NO-3,NH+4)was 20.7μg·m-3,accounting for 30.5%of PM2.5,which was related to the secondary generation by the large amount emission of SO2 and NO2 into the atmosphere.OC(12.6μg·m-3)and EC(6.6μg·m-3)accounted for 18.6%and 9.7%of PM2.5,respectively.Both the value of OC/EC(2.06)and the proportion(63.1%)of SOC in OC all indicated that the secondary organic pollution was serious.The typical crustal elements of Si and Ca accounted for 29.8%and 22.8%of total elements,indicating that dust pollution had a great influence on PM2.5.The results of source apportionment showed that the contribution of main sources of PM2.5 in autumn and winter in Changzhi were 17.0%of vehicle source,16.5%of coal combustion source,14.6%of dust source,13.9%of secondary nitrates,11.0%of secondary sulfates,10.8%of secondary organic aerosols,9.3%of industry process source,1.9%of biomass burning source and 5.0%of other sources.Therefore,in order to further reduce the concentration of PM2.5 in the ambient air of Changzhi,it is necessary to strengthen the control the primary emissions of vehicle,coal combustion and dust to reduce the emissions of the primary pollutants(SO2 and NO2),so as to realize the control of secondary source precursors.
作者
张毅
ZHANG Yi(Changzhi Ecological and Environmental Monitoring Center of Shanxi Province,Changzhi,046000,China)
出处
《环境化学》
CAS
CSCD
北大核心
2020年第6期1699-1708,共10页
Environmental Chemistry
基金
大气重污染成因与治理攻关项目(DQGG-05-13)资助
关键词
长治市
秋冬季
PM2.5
组分特征
来源解析
Changzhi
autumn and winter
PM2.5
component characteristics
source apportionment
作者简介
通讯联系人:张毅,E-mail:czjczzy@163.com
