三峡库区地质高背景区土壤-油菜重金属迁移特征  

Migration Characteristics of Heavy Metal Elements between Soil and Rape in the High Geological Background Area of Three Gorges Reservoir Region

作　　者：双燕 杨振鸿 胡峰 SHUANG Yan;YANG Zhenhong;HU Feng(Green Intelligence Environmental School,Yangtze Normal University,Chongqing 408100,China;Chongqing Institute of Geology and Mineral Resources,Chongqing 401120,China)

机构地区：[1]长江师范学院绿色智慧环境学院,重庆408100 [2]重庆地质矿产研究院,重庆401120

出　　处：《三峡生态环境监测》2023年第4期56-65,共10页Ecology and Environmental Monitoring of Three Gorges

基　　金：重庆市自然科学基金计划(cstc2019jcyj-msxmX0201);重庆市高校创新研究群体(CXQT19030)。

摘　　要：三峡库区广泛分布的黑色岩系富含镉(Cd)、铬(Cr)、镍(Ni)、锌(Zn)等重金属元素,导致土壤重金属元素含量显著高于我国土壤背景值,成为典型的地质高背景区。本文选择三峡库区地质高背景区油菜种植地为研究对象,分析了土壤-油菜系统中砷(As)、Cd、Zn、铜(Cu)、铅(Pb)、Cr、Ni、汞(Hg)等重金属元素含量分布特征、富集迁移规律以及影响因素。研究结果表明,研究区油菜种植地土壤中Cd、Cr、Cu、Hg、Ni等重金属含量显著高于我国土壤背景值,单因子污染指数评价显示土壤As、Zn、Hg、Pb等重金属均属于无污染等级,Cu、Ni污染程度受到pH影响,Cd为重度污染和极高生态风险。不同重金属元素在油菜各部位含量差异明显,Pb、Cd、As等生物非必需元素更倾向进入茎、果荚,营养元素Cu和Zn则在油菜籽中含量较高,而Cr易在果荚中富集。研究区土壤中重金属元素含量、土壤pH、重金属元素间的拮抗作用以及油菜解毒机制可能是影响重金属元素在土壤-油菜各部位富集迁移的重要因素。The black rock series widely distributed in the Three Gorges Reservoir area are rich in heavy metal elements such as Cd,Cr,Ni and Zn,leading to significantly higher levels of heavy metal elements in the soil from the Three Gorges Reservoir area than the national average and becoming a typical high geological background area.This study selected rape planting areas in the high geological background area of the Three Gorges Reservoir region as the research object.The major factors influencing the migration of heavy metals between soils and different parts of rapes were researched through the analysis of geochemical characteristics of heavy metals in the soil-rape system.The results showed that Cd,Cr,Cu,Hg and Ni in the soil of the rape planting areas in the re⁃search area were significantly higher than the national average background values.The single-factor pollution index evaluation showed that heavy metals such as As,Zn,Hg,and Pb in the soils were all in the non-pollution grade.In contrast,the pollution de⁃gree of Cu and Ni was affected by pH value,and Cd showed severe pollution and extremely high ecological risk.The concentra⁃tions of the heavy metals showed a significant difference from the seed,pod,and stem of the same rape.Biologically non-essential elements such as Pb,Cd,and As tended to enter the stems and pods,while nutrients such as Cu and Zn were more abundant in rape seeds,and Cr tended to accumulate in the pods.The level of the element content and pH in the soil of study area,the antago⁃nistic effects between elements,and the detoxification mechanism of rape may be important factors affecting the enrichment and mi⁃gration of heavy metal elements in different parts of the soil-rape system.

关 键 词：三峡库区 地质高背景 重金属 油菜 土壤 

分 类 号：X53[环境科学与工程—环境工程]