摘要
大气降尘可以反映大气颗粒物的自然沉降量,具有重要的环境指示意义.降尘重金属通过大气沉降进入土壤或水体,对人体健康、植物和水生生物等有危害作用.为了了解北京冬季降尘中重金属的含量水平、富集程度以及综合污染特征,于2013年11月-2014年3月收集了北京大气降尘样品49组,并用Elan DRC II型电感耦合等离子体质谱仪（ICP-MS）测试了降尘中Cd、Cr、Pb、Cu、Zn、Ni、Co、V、Bi、Mo等10种重金属的含量.结果表明,北京冬季降尘中重金属Cd、Bi和Mo的平均含量不足10 mg·kg^-1,Co、Ni和V的平均含量在10-100 mg·kg^-1之间,而Pb、Cr、Cu和Zn的平均含量均超过100mg·kg^-1;Cd、Zn、Cu的含量均超出土壤环境二级标准值,其中城区和近郊Cd、Zn、Cu的二级超标率分别为100%、97%、93.9%和100%、100%、81.2%.富集因子研究结果表明,Bi、Cu、Ni、Pb微量富集,主要来源于地壳或土壤源;Cd、Cr、Mo、Zn轻度富集,受自然源和人为源共同作用.论文在传统单一污染评价基础上,提出了＂降尘重金属综合污染指数＂模型,并探讨了北京降尘重金属的综合污染特征,结果表明北京城区冬季降尘中重金属的综合污染指数排序为Cd〉Zn〉Cu〉Pb〉Cr〉Ni〉V〉Co,并且Cd、Zn、Cu和Pb是冬季北京城区降尘中显著污染因子,其中Cd和Zn为极显著污染因子;北京近郊冬季降尘中重金属的综合污染指数排序为Cd〉Zn〉Cu〉Pb〉Cr〉Ni〉Co〉V,并且Cd、Zn、Cu、Pb和Cr是冬季北京近郊降尘中显著污染因子,其中Cd和Zn为极显著污染因子.
Dust reflects the natural subsidence of particles and is thus generally accepted as an important environmental indicator. Dust heavy metals find their way into soil or water via atmospheric deposition,potentially damaging plants,aquatic organisms,as well as human beings. In order to study the concentration levels,enrichment degrees,and comprehensive pollution characteristics of the dust heavy metals Cd,Cr,Pb,Cu,Zn,Ni,Co,V,Bi,and Mo in winter in Beijing,49 groups of dust samples were collected from different locations within the city from November 2013 to March 2014. Heavy metal content（mass percentage） was then measured using Elan DRC Ⅱ type inductively-coupled plasma mass spectrometry（ICP-MS）. Results showed that the average content of Cd,Bi,and Mo was less than 10 mg·kg^-1,that of Co,Ni,and V was between 10 and 100 mg·kg^-1,while that of Pb,Cr,Cu,and Zn was more than 100 mg·kg^-1. The amount of Cd,Zn,and Cu in dust samples was generally higher than their secondary standard values in the soil environment. The secondary standard excess rates of Cd,Zn,and Cu were 100 %,97 %,and 93. 9 % in urban environments,and 100 %,100 %,and 81. 2 % in suburban environments,respectively. Results also indicated slight enrichment of Bi,Cu,Ni,and Pb,mainly derived from crustal or soil sources,while Cd,Cr,Mo,and Zn,exhibited mild enrichment,caused by a combination of natural and artificial sources. The paper proposes a ＂ dust heavy metal comprehensive pollution index＂ model,based on the traditional single pollution assessment method,so as to explore comprehensive pollution characteristics of dust heavy metals in Beijing. Results for the dust heavy metal comprehensive pollution index in Beijing City were in the order of Cd Zn Cu Pb Cr Ni V Co. Cd,Zn,Cu,and Pb were identified as key pollution factors,with Cd and Zn as primary factors. Results for the dust heavy metal comprehensive pollution index in Beijing suburbs was Cd Zn Cu Pb Cr Ni Co V. Cd,Zn,Cu,Pb,and Cr were key pollution factors,with Cd and Zn as primary factors.
作者
熊秋林
赵文吉
李大军
周涛
XIONG Qiu-lin;ZHAO Wen-ji;LI Da-jun;ZHOU Tao(Faculty of Geomaties,East China University of Technology,Nanehang 330013,China;School of Resourees,Environment ＆ Tourism,Capital Normal University,Beijing 100048,China;College of Tourism and Urban Rural Planning,Chengdu University of Technology,Chengdu 610059,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2018年第9期4051-4059,共9页
Environmental Science
基金
教育部博士点基金项目（20111102110004）
首都师范大学研究生国际交流与联合培养项目（028175534000）
关键词
降尘
重金属
含量水平
富集因子
综合污染指数
显著污染因子
dust
heavy metals
concentration level
enrichment factor
comprehensive pollution index
key pollution factors
