摘要
河流沉积物重金属污染问题日益突出,严重威胁流域生态系统健康。以黄河流域泾河崆峒段为研究区,采集91个河流表层沉积物样品,测定并分析沉积物As、Cd、Cr、Cu、Hg、Ni、Pb和Zn共8项重金属元素含量及其空间分布特征。采用地累积指数(I_(geo))和污染负荷指数(PLI)系统量化重金属污染特征,并联合应用自组织神经网络(SOM)模型、相关性分析和正定矩阵因子分解(PMF)模型定量解析沉积物重金属污染来源及其贡献率。结果表明:泾河崆峒段河流表层沉积物重金属含量的平均值高低依次为Cr(65.66 mg/kg)>Zn(55.63 mg/kg)>Ni(21.78 mg/kg)>Pb(17.50 mg/kg)>Cu(14.07 mg/kg)>As(10.94 mg/kg)>Cd(0.19 mg/kg)>Hg(0.032 mg/kg)。除Cd和Hg外,As、Cr、Cu、Ni、Pb和Zn含量的均值均低于甘肃省土壤背景值和黄土高原土壤背景值,且As、Cd和Cr含量的均值分别是中国水系沉积物背景值的1.22、1.46和1.22倍。沉积物重金属含量空间分布具有明显的差异性,所有元素高含量和污染相对较重的区域均分布于人类活动强烈和入河口周边流域,且Hg的空间异质性最强。Cd是泾河崆峒段亟需关注的首要污染元素,Hg、Pb、Cr和Zn存在局部污染,Cu、Ni和As为清洁无污染。沉积物重金属的富集可能受污水交通源、农业源、金属冶炼加工源、电镀制造工业源和自然源的共同影响,贡献率依次为33.33%、27.21%、11.02%、15.49%和12.95%。
There is a growing concern over heavy metal pollution in river sediments,which gravely impacts the ecological health of the fluvial ecosystem.Taking the Kongtong section of the Jing River,Yellow River Basin as the study area,a total of 91 surface sediment samples were collected from the studied river.The contents of eight heavy metals,including As,Cd,Cr,Cu,Hg,Ni,Pb and Zn,were determined and analyzed,along with their spatial distribution characteristics in sediments.The geo-accumulation index(I_(geo))and pollution load index(PLI)were utilized to systematically quantify the characteristics of heavy metal pollution in sediments.An integrated method employing the self-organizing map(SOM)model,correlation analysis,and positive matrix factorization(PMF)model was also applied to quantitatively analyze heavy metal pollution sources and their contribution rates.The results indicated that the average content of heavy metals in the surface sediments from the Kongtong section of the Jing River followed a descending order of Cr(65.66 mg/kg)>Zn(55.63 mg/kg)>Ni(21.78 mg/kg)>Pb(17.50 mg/kg)>Cu(14.07 mg/kg)>As(10.94 mg/kg)>Cd(0.19 mg/kg)>Hg(0.032 mg/kg).Except for Cd and Hg,the average contents of As,Cr,Cu,Ni,Pb and Zn were lower than the soil background values of Gansu Province and the loess plateau.The mean contents of As,Cd and Cr were 1.22,1.46 and 1.22 times higher than the background values for sediments in Chinese river basins,respectively.The spatial distribution of heavy metal content in sediments displayed noticeable heterogeneity,with regions characterized by elevated concentrations and relatively severe pollution predominantly located in areas with intense human activities and surrounding river mouths.Furthermore,spatial heterogeneity was most pronounced in the case of Hg.The pollution assessment results suggested that Cd was the primary pollutant element requiring urgent attention in the studied basin,while Hg,Pb,Cr and Zn exhibited localized pollution.Cu,Ni and As were considered clean and non-polluted.Source appor
作者
李军
脱新颖
马利邦
周发元
李开明
马晓红
岳斌
臧飞
Li Jun;Tuo Xinying;Ma Libang;Zhou Fayuan;Li Kaiming;Ma Xiaohong;Yue Bin;Zang Fei(College of Urban Environment,Lanzhou City University,Lanzhou 730070,P.R.China;College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,P.R.China;College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,P.R.China)
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2024年第6期1782-1794,共13页
Journal of Lake Sciences
基金
甘肃省科技重大专项项目(22ZD6WA057)
甘肃省科技计划资助项目(24JRRA530,23JRRA1174)联合资助。
关键词
黄河流域
泾河
沉积物
重金属
地累积指数
污染负荷指数
来源解析
Yellow River Basin
Jing River
sediment
heavy metals
geo-accumulation index
pollution load index
source apportionment
