典型岩溶县土壤重金属含量、 来源及生态风险评价  

Content, Sources, and Ecological Risk Assessment of Heavy Metals in Soil of TypicalKarst County

作　　者：胡兆鑫[1,2] 吴泽燕 罗为群[1,2] 谢运球 HU Zhao-xin;WU Ze-yan;LUO Wei-qun;XIE Yun-qiu(International Research Centre on Karst under the Auspices of United Nations Educational,Scientific and Cultural Organization,Key Laboratory of Karst Dynamics,Ministry of Natural Resources/Guangxi,Institute of Karst Geology,Chinese Academy of Geological Sciences,Guilin 541004,China;Pingguo Guangxi,Karst Ecosystem,National Observation and Research Station/Pingguo Baise,Karst Ecosystem,Guangxi Observation and Research Station,Pingguo 531406,China)

机构地区：[1]中国地质科学院岩溶地质研究所,自然资源部/广西岩溶动力学重点实验室,联合国教科文组织国际岩溶研究中心,桂林541004 [2]广西平果喀斯特生态系统国家野外科学观测研究站/百色平果喀斯特生态系统广西野外科学观测研究站,平果531406

出　　处：《环境科学》2024年第9期5506-5516,共11页Environmental Science

基　　金：国家重点研发计划项目(2022YFF1300702);中国地质调查局地质调查项目(DD20160324,DD20230453);广西科技基地和人才专项(桂科22-035-130-05)。

摘　　要：岩溶地区土壤重金属具有明显的高背景值特征,在岩溶地区开展县域尺度土壤重金属生态风险评价和识别重金属来源对土壤污染管控及土地资源管理具有重要意义.以广西典型岩溶县平果市为研究对象,采用网格化法采集表层、深层土样3151件,组合形成分析样品785件,测定其As、Cd、Cr、Cu、Hg、Ni、Pb和Zn共8种重金属元素含量.运用统计分析、插值分析、因子分析和绝对主成分-多元线性回归模型(APCS-MLR)对重金属含量特征及来源进行分析,以深层(150~200 cm)土壤重金属元素含量作为背景值,采用地累积指数(Igeo)和潜在生态危害指数(RI)对研究区表层(0~20 cm)土壤重金属进行生态风险评价.结果显示,研究区深层土壤中重金属含量平均值明显高于广西C层土壤背景值,表层土壤重金属含量平均值明显高于广西A层土壤背景值,土壤重金属元素含量空间分布总体呈现出岩溶区高、非岩溶区低的特征;As、Cr、Ni、Pb和Zn的来源主要为成土母质源,贡献率分别为74.36%、84.59%、93.69%、79.67%和78.17%;Cd的来源主要为成土母质源和未知源,贡献率分别为37.33%和31.05%;Cu的来源主要为成土母质源和未知源,贡献率分别为59.07%和40.23%;Hg的来源主要为构造活动与成矿作用源和未知源,贡献率分别为52.49%和30.65%;地累积指数(Igeo)显示表层土壤主要受到Cd污染,轻度以上污染占47.78%;潜在生态危害指数(RI)显示表层土壤重金属综合潜在生态危害轻微、中等、强、很强等级面积占比分别为80.78%、14.97%、2.51%、1.64%.Soil heavy metals in karst areas have obvious high background value characteristics.Conducting county-level soil heavy metal ecological risk assessment and identifying heavy metal sources in karst areas are of great significance for soil pollution control and land resource management.Taking Pingguo City,a typical karst county in Guangxi Province,as the study object,3151 surface and deep soil samples were collected using the grid method and combined to form 785 analytical samples.The contents of eight heavy metal elements,including As,Cd,Cr,Cu,Hg,Ni,Pb,and Zn,were determined.The content characteristics and sources of heavy metals were analyzed using statistical analysis,interpolation analysis,factor analysis,and the absolute principal component-multiple linear regression model(APCS-MLR).Using the content of heavy metal elements in deep soil(150-200 cm)as background values,the ecological risk assessment of heavy metals in surface soil(0-20 cm)in the study area was conducted using the geo-accumulation index(Igeo)and potential ecological risk index(RI)methods.The results showed that the average content of heavy metal elements in the deep soil of the study area was significantly higher than the background value of the C layer soil in Guangxi Province,and the average content of heavy metal elements in the surface soil was significantly higher than the background value of the A layer soil in Guangxi Province.The spatial distribution of soil heavy metal element content generally showed the characteristics of high in karst areas and low in non-karst areas.The main sources of As,Cr,Ni,Pb,and Zn were soil parent materials,with contribution rates of 74.36%,84.59%,93.69%,79.67%,and 78.17%,respectively.The main sources of Cd were soil parent material sources and unknown sources,with contribution rates of 37.33%and 31.05%,respectively.The main sources of Cu were soil parent materials and unknown sources,with contribution rates of 59.07%and 40.23%,respectively.The main sources of Hg were tectonic activity and mineralization,as w

关 键 词：岩溶 高背景 重金属 地累积指数(Igeo) 潜在生态危害指数(RI) 

分 类 号：X53[环境科学与工程—环境工程]