摘要
以黄河干流底泥重金属为研究对象,利用富集系数、地累积指数和潜在生态分析指数的方法,分析了5种不同土地利用类型区(农田、水域、林地、城市和工业)河流底泥的6种重金属元素(Cu、Ni、Pb、Zn、Cr和Cd)含量特征,评价了不同土地利用类型区底泥重金属的生态风险水平.结果表明:Cu、Zn、Cr和Cd的含量在工业区最大,水域区最小.Ni和Pb含量的最大值分别出现在水域区和城市区,最小值都在林地区.各重金属的含量与背景值和土壤环境质量一级标准相比,工业区和农田区的超标现象较严重,水域区较轻,重金属元素尤其是Cr和Cd在不同土地利用类型区都有一定程度的累积.富集系数和地累积指数评价结果表明,工业区和农田区重金属为微富集水平,属轻度污染;林地区和水域区属于无富集、无污染的水平;城市区为微富集水平,无污染.Zn、Cr,尤其是Cd是研究区主要的富集和污染因子.潜在生态风险指数评价结果显示,Cd为主要的潜在生态风险因子,且在工业区、农田区和林地区属中风险等级;从RI来看,工业区存在中风险等级的潜在生态风险,其余(农田、林地、城市和水域)均为低风险.根据研究结果,黄河流域应重点关注工业区和农业区重金属Cd和Cr的污染.
Taking heavy metals in sediments of the Yellow River as the research object,this paper analyzed the concentration characteristics and assessed the ecological risk of 6 heavy metals(Cu,Ni,Pb,Zn,Cr and Cd)in different land use types:cropland area(CRS),water area(WAS),forest area(FRS),urban area(URS)and industrial area(INS),which could provide some basis for environmental managers to make decisions.The results showed that the contents of Cu,Zn,Cr and Cd were the largest in INS and the smallest in WAS.The maximum Ni and Pb contents appeared in WAS and URS respectively,and the minimum values were in the FRS.Compared with the background value and the first-grade standards of soil environmental quality,the phenomenon of exceeding the standards in industrial area and farmland area exceeded the standard seriously,and the water area was relatively light.Heavy metal elements,especially Cr and Cd,have accumulated to a certain extent in different land use types.The evaluation results of the enrichment coefficient(EF)and geo-accumulation index(Igeo)showed that the heavy metals in INS and CRS were at the level of minor enrichment and reached the level of slight pollution,FRS and WAS were at the level of non-enrichment and non-pollution,and URS was at the level of minor enrichment but not polluted.The assessment of the potential ecological risk index(ERI and RI)showed that Cd was the main potential ecological risk factor,and it reached a medium risk level in INS,CRS and FRS.According to the RI value,INS was of medium risk,while the rest(CRS,FRS,URS and WAS)was of low risk.According to the study results,the study of heavy metal pollution of Cd and Cr in INS and CRS should be focused on in the Yellow River Basin.
作者
郝建秀
任珺
陶玲
方红兵
HAO Jian-xiu;REN Jun;TAO Ling;FANG Hong-bing(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Key Laboratory of Yellow River Water Environment in Gansu Province,Lanzhou 730070,China)
出处
《兰州交通大学学报》
CAS
2020年第6期99-105,共7页
Journal of Lanzhou Jiaotong University
基金
国家自然科学基金(51668034)。
关键词
底泥
重金属
土地利用类型
黄河
sediment
heavy metal
land use types
the Yellow River
