贵阳市降雨前后城市道路灰尘重金属含量动态变化  

Dynamic change of heavy metals in street dust before and after rain in Guiyang City

作　　者：杨海龙[1] 李晓燕[1] YANG Hailong LI Xiao Yan(School of Geographic and Environmental Sciences, Guizhou Normal University, Guiyang, 550001, China)

机构地区：[1]贵州师范大学地理与环境科学学院,贵阳550001

出　　处：《环境化学》2017年第10期2206-2213,共8页Environmental Chemistry

基　　金：国家自然科学基金(41161079);贵州师范大学研究生创新基金资助~~

摘　　要：为探究降雨对城市道路灰尘重金属分布的影响,以贵阳市为研究区域,分别在两次降雨前后于贵阳市主城区主干道20个十字路口处采集灰尘样品,分析As、Cd、Cu、Ni、Pb、Zn等6种重金属含量,研究降雨前后城市道路灰尘重金属含量动态变化及粒级载荷特征.结果表明:1)两次降雨前/后灰尘As、Cd、Cu、Ni、Pb、Zn含量平均值分别为9.41/9.51、0.637/0.675、141/129、24.7/25.4、67.7/69.2、276/346 mg·kg^(-1),灰尘Cu含量雨前高于雨后,灰尘Zn含量雨后明显高于雨前,且倾向于向粗粒级中富集;2)雨后灰尘粗粒级质量百分比增加,细粒级质量百分比降低,降雨后重金属在粗粒级灰尘中的载荷增加;3)降雨对道路灰尘重金属含量的影响与灰尘粒级组成有关.不同降雨过程对道路灰尘重金属分布的影响可能存在些许差异.Twenty dust samples at crossroads in a urban area in Guiyang City were collected before and after rain to investigate the effect on the concentrations of heavy metals in street dust by rain.The concentrations of As,Cd,Cu,Ni,Pb and Zn were analysed. The results show that the average levels of As,Cd,Cu,Ni,Pb and Zn in dust before and after rain were 9.41/9.51,0.637/0.675,141/129,24.7/25.4,67. 7/69. 2 and 276/346 mg·kg（-1） respectively. The level of Cu in the dust before rain was higher than after rain,while the Zn concentration was the opposite which is likely to be accumulated in the coarse fractions of dust. The mass percentage of the coarse fraction of street dust increased and those of fine fractions decreased after rain,and the contribution to heavy metals from the coarse fractions of street dust also increased. The effect on the level of heavy metals in dust by rain is probably related to the particle size composition of dust,and the vavation of heavy metal contents in street dust during different rainfall process may be lightly different.

关 键 词：重金属 道路灰尘 降雨 贵阳市 

分 类 号：X513[环境科学与工程—环境工程]