摘要
研究桂东南流域表层沉积物重金属分布特征和来源,评价其潜在风险,为西南地区矿区流域水体重金属污染防控与治理提供科学指导。以西江流域支流——义昌河流域为研究对象,采集不同季节流域干支流表层沉积物样品,分析7种重金属(Cu、Pb、Zn、Ni、Mn、Cr、Cd)含量的时空分布特征和来源,采用地累积指数法和潜在生态风险指数法协同评估重金属积累的潜在风险。结果表明,沉积物重金属平均含量,Cu、Pb、Ni、Cr在秋季最高,Cd、Zn在夏季最高,Mn在春季最高;Pb、Zn、Cd含量上游>下游>中游,而Cu、Cr、Mn含量下游>中游>上游。相关性分析表明,Pb、Zn、Cd之间以及Cu、Ni之间具有相同来源,受地质背景和人类活动影响较大。地累积指数评价表明,Cd为中度污染,Mn为偏中度污染,其余重金属为轻度或无污染;潜在生态风险指数评价进一步表明,Cd是最主要的生态风险贡献因子,危害程度为高风险,其余重金属危害程度均为轻微。
Soil and water losses in mining basins can lead to the migration and diffusion of heavy metals,which can pollute neighboring soils and water bodies.In this study,the Yichang River,a tributary of the Xijiang River Basin in southeastern Guangxi(Wuzhou),was used as the research object,and surface sediment samples were collected from the dry and tributary streams of the basin in different seasons,and the spatial and temporal distribution characteristics of the contents of seven heavy metals(Cu,Pb,Zn,Ni,Mn,Cr,and Cd)were analyzed to synergistically assess the potential risk of heavy me tal accumulation by using the geo-accumulation index method and the potential ecological risk index method.The results showed that the mean contents of Cu,Pb,Ni and Cr in sediments were highest in fall,Cd and Zn in summer,and Mn in spring;the contents of Pb,Zn and Cd were upstream>downstream>midstream,while the contents of Cu,Cr and Mn were downstream>midstream>upstream.Correlation analysis showed that Pb,Zn and Cd had the same source as well as Cu and Ni,which is influenced by geological background and human activities.The evaluation results of the geo-accumulation index method showed that Cd was moderately polluted,Mn was bi-moderately polluted,and the rest of the heavy metals were mildly or not polluted.The evaluation method results of potential ecological risk index further indicated that Cd was the most important ecological contributing factor with high risk of harm,and the remaining heavy metals had slight harm.The results of the study can provide scientific guidance for the prevention,control and management of heavy metal pollution in the water bodies of mining watersheds in Southwest China.
作者
李萍
刘春
张立杰
刘钊琳
张宇恒
樊光辉
朱颖洁
左悦
LI Ping;LIU Chun;ZHANG Lijie;LIU Zhaolin;ZHANG Yuheng;FAN Guanghui;ZHU Yingjie;ZUO Yue(School of Environment and Climate,Jinan University,Guangzhou 510632,P.R.China;School of Life Science and Technology,Jinan University,Guangzhou 510632,P.R.China;School of Mechanical and Resource Engineering,Wuzhou University,Wuzhou 543002,P.R.China;Wuzhou Hydrological Center,Wuzhou 543000,P.R.China)
出处
《水生态学杂志》
北大核心
2025年第2期160-170,共11页
Journal of Hydroecology
基金
广西自然科学基金(2022GXNSFDA080009)
国家自然科学基金(42007049)
关键词
表层沉积物
重金属
分布特征
风险评价
桂东南流域
surface sediment
heavy metals
distributional characteristics
risk evaluation
southeast Guangxi
