摘要
研究了北京市不同功能区道路灰尘中重金属Cd、Hg、Cr、Cu、Ni、Pb、Zn和16种多环芳烃(PAHs)的分布状况和污染水平.结果表明,北京市道路灰尘中重金属Cd、Hg、Cr、Cu、Ni、Pb和Zn的浓度的平均值分别为710 ng/g、307 ng/g、85.0μg/g、78.3μg/g、41.1μg/g、69.6μg/g和248.5μg/g,显著低于世界上已有调研的大多数城市和国内的沈阳市和上海市;道路灰尘中∑16PAHs的浓度的平均值为0.398μg/g,也大大低于国内已有调研的邯郸市、天津市和上海市.弗里德曼非参数检验表明各功能区道路灰尘中重金属含量存在显著差异:居民居住区和绿化区域道路灰尘上重金属和PAHs的吸附量较小,而在机动车密度较大,车辆行驶较慢的城市交通区的道路灰尘上重金属和PAHs的污染都较严重.道路灰尘重金属浓度Zn>Cr>Cu>Pb>Ni>Cd>Hg,这种污染状况与世界其他各大城市是一致的.地积累指数评价法表明北京市道路灰尘上Cd、Zn和Cu处于中度污染水平,Cr和Pb处于轻度污染水平,Ni处于无实际污染水平.∑16PAHs的污染水平在不同功能区的差异比较大:公园道路灰尘为无污染至轻度污染水平,居民区道路灰尘处于中度至严重污染水平,交通密集区PAHs处于严重污染至极度污染水平.重金属和PAHs的质量负荷主要集中在粒径<300μm的道路灰尘上,因此城市清扫车在去除地表颗粒物时不仅应当关注小尺度的颗粒物,应该通过升级除尘装备,尽量去除300μm以下的道路灰尘.
This paper investigated the contamination levels of heavy metal and polycyclic aromatic hydrocarbons（PAHs） in street dusts in different functional areas in urban Beijing.Results show that the mean concentrations of Cd,Hg,Cr,Cu,Ni,Pb and Zn in street dusts in Beijing are 710 ng/g,307 ng/g,85.0 μg/g,78.3 μg/g,41.1 μg/g,69.6 μg/g and 248.5 μg/g,respectively,which are significantly lower than those in most cities around the world and Shenyang,Shanghai in China.The mean concentration of ∑16PAHs in street dusts in Beijing is 0.398 μg/g,which is also lower than those of Handan,Tianjin and Shanghai.Non-parametric Friedman test demonstrates significant differences of heavy metal contents on street dusts from different functional zones.Street dusts in residential area and parks have lower heavy metal and PAHs concentrations than the street dusts from areas of high traffic density.The concentrations of heavy metals follow the order Zn〉Cr〉Cu〉Pb〉Ni〉Cd〉Hg,which is consistent with t.he situation in other cities around the world.The geoaccumulation index analysis shows that street dust in urban Beijing is moderately polluted by Cd,Zn and Cu,little polluted by Cr and Pb and practically unpolluted by Ni.The contamination levels of ∑16PAHs on street dusts vary greatly in different functional zones with parks little polluted,residential areas moderately to strongly polluted and traffic related areas strongly polluted to extremely polluted.Mass loading of heavy metals and PAHs is largely associated with street dusts of size range 〈300 μm.Therefore,the urban sweeping vehicles should update the dust sweeping devices to remove not only the fine particle but also the coarser particles.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2010年第1期159-167,共9页
Environmental Science
基金
国家重点基础研究发展规划(973)项目(2006CB403403)
国家自然科学青年基金项目(50809006)
教育部留学人员科研启动基金项目
国家重点实验室专项基金课题项目(08ESPCT-Y)
关键词
道路灰尘
重金属
PAHS
污染水平
北京
street dusts
heavy metal
polycyclic aromatic hydrocarbons（PAHs）
contamination level
Beijing
