摘要
街道灰尘重金属特征是评价城市环境质量的有效手段.对我国典型农业城市许昌市的街道灰尘Cu、Pb、Zn、Cr、Ni、Co、Mn和As等重金属元素含量水平和空间分布特征进行了分析,并采用地累积污染指数法和潜在生态风险指数法对街道灰尘中重金属的环境风险进行了评价.结果表明,Cu、Pb、Zn、Cr、Ni、Co、Mn和As的平均值分别为25.4、41.9、145.3、96.7、18.5、9.0、408.1和7.8μg·g-1,其中Ni、Co、Mn和As的平均值均小于河南省土壤背景值,而Cu、Pb、Zn和Cr的平均值分别是背景值的1.80、2.14、2.42和1.52倍,说明街道灰尘中这几种重金属元素聚集趋势较为明显.空间分布上,除Co、Mn和As外,Cu、Pb、Zn、Cr和Ni均表现出从西北向东南变小的趋势,反映了城市不同功能区划和人类活动强度的差异.地累积污染指数法的评价结果表明,许昌市街道灰尘中Ni、Co、Mn和As属于无污染水平,而Cu、Pb、Zn和Cr均属于轻度污染,污染水平是Zn>Pb>Cu>Cr.许昌市街道灰尘重金属潜在生态风险指数为40.71,属于低生态风险水平.
The characteristic of heavy metals in street dust is an effective means to evaluate the quality of the urban environment. The content and spatial distribution of heavy metals in street dust of Xuchang City was analyzed. The geo-accumulation pollution index and potential ecological risk index were used to assess the environmental risks of heavy metals in street dust. The results showed that the mean concentration of Cu, Pb, Zn, Cr, Ni, Co, Mn and As was 25.4, 41.9, 145.3, 96. 7, 18.5, 9.0, 408.1 and 7.8 μg.g-1 , respectively. Concentrations of Ni, Co, Mn and As were lower than the background values in soil of Henan Province. Cu, Pb, Zn and Cr concentrations were 1.80, 2.14, 2.42 and 1.52 times as high as the background values, indicating their enrichment in street dust. Except for Co, Mn and As, the spatial distribution of Cu, Pb, Zn, Cr and Ni showed a decreasing trend from the northwest to the southeast, reflecting differences of urban function zoning and human activity intensity. The assessment results of geo-accumulation pollution index showed that Ni, Co, Mn and As were at pollution-free level, while the pollution of Cu, Pb, Zn and Cr was mild, with pollution levels in descending order： Zn 〉 Pb 〉 Cu 〉 Cr. The potential ecological risk index was 40. 71, belonging to low level of ecological risk.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2013年第10期4017-4023,共7页
Environmental Science
基金
河南省高等学校青年骨干教师资助计划项目
河南省科技厅项目(122102310421)
河南省教育厅项目(2011B170014)
许昌市科技局项目(3009)
关键词
重金属
地累积污染指数
潜在生态风险指数
街道灰尘
许昌
heavy metal
geo-accumulation pollution index
potential ecological index
street dust
Xuchang City
