广西内苗溪沉积物重金属污染及其生态风险评价  

Heavy metal pollution in sediments of Neimiao Creek,Guangxi Autonomous Region and its ecological risk assessment

作　　者：赵华荣[1,2,3] 李梦豪 姚越 何妹 冯昭阳 ZHAO Huarong;LI Menghao;YAO Yue;HE Mei;FENG Zhaoyang(School of Environmental Science and Engineering,Guilin University of Technology,Guilin 541006,China;Guangxi Karst Area Water Pollution Control and Water Safety Assurance Collaborative Innovation Center,Guilin University of Technology,Guilin 541006,China;Guangxi Environmental Pollution Control Theory and Technology Key Laboratory,Guilin University of Technology,Guilin 541006,China)

机构地区：[1]桂林理工大学环境科学与工程学院,广西桂林541006 [2]桂林理工大学广西岩溶地区水污染控制与用水安全保障协同创新中心,广西桂林541006 [3]桂林理工大学广西环境污染控制理论与技术重点实验室,广西桂林541006

出　　处：《人民长江》2023年第2期112-119,共8页Yangtze River

基　　金：广西重点研发项目(桂科AB21075007)。

摘　　要：广西德保县内苗铅锌矿是典型的以采代探对周边环境造成污染的矿山。为了研究该矿对内苗溪的污染情况,沿内苗溪采集了13个沉积物样,对沉积物中Cu、As、Cd、Pb、Zn、Cr和Mn元素的总量和形态进行了分析,并运用地累积指数法、潜在生态风险指数法对沉积物中重金属的污染程度和生态风险进行了评价。结果表明:(1)除Cr和Mn的平均含量低于背景值外,Cd、Zn、As、Pb、Cu的平均含量分别为背景值的518.53,52.64,31.53,12.37,2.58倍。沉积物中Cu、Cd、Zn、Cr和Mn含量沿内苗溪向下游呈增加趋势,As和Pb向下游则呈减少趋势。(2)沉积物中Cu在大部分采样点以残渣态为主,沿内苗溪上游至下游,As元素有机物结合态呈增加趋势,Cd可交换态呈减少趋势,铁锰氧化物结合态呈增加趋势,Pb碳酸盐结合态、铁锰氧化物结合态和有机态均有所增加,Zn可交换态明显减少,碳酸盐结合态和铁锰氧化物结合态呈增加趋势,Cr元素以可交换态为主,无明显变化趋势,Mn元素碳酸盐结合态呈增加趋势,可交换态呈减少趋势。(3)沉积物相关性表明,Zn与Cd,Pb与As及Cr与Mn三组元素中存在明显同源性。地累积指数表明,Cd为极严重污染,Zn为强-极严重污染,As为中等-强污染,Pb为中等污染,Cu为轻度-中等污染,Cr和Mn为无污染。潜在生态风险指数法表明,沉积物复合潜在生态风险极高,Cd、As、Pb、Zn生态风险程度较高,Cu、Mn、Cr为低生态风险。Neimiao Lead-zinc Mine in Debao County of Guangxi Autonomous Region is a typical mine that pollutes the surrounding environment by mining instead of exploration.In order to study the pollution of the mine to the Neimiao Creek,13 sediment samples were collected along the Neimiao Creek,and the total amount and form of Cu,As,Cd,Pb,Zn,Cr and Mn elements in the sediments were analyzed,the pollution degree and ecological risk of heavy metals in the sediments were evaluated by the geo-accumulation index method and the potential ecological risk index method.The results showed that:(1)except that the average contents of Cr and Mn were lower than the background values,the average contents of Cd,Zn,As,Pb and Cu were 518.53,52.64,31.53,12.37 and 2.58 times of the background values,respectively.The contents of Cu,Cd,Zn,Cr and Mn in sediments showed an increasing trend from Neimiao Creek to the downstream,while As and Pb showed a decreasing trend.(2)Cu in sediments was mainly in residual form at most sampling points.From upstream to downstream,the organic matter binding state of As element showed an increasing trend.The exchangeable state of Cd showed a decreasing trend,and the iron-manganese oxide bound state showed an increasing trend.The carbonate bound state,iron manganese oxide bound state and organic state of Pb increased.The exchangeable state of Zn decreased significantly,carbonate binding state and iron manganese oxide binding state showed an increasing trend.Cr element was mainly in exchangeable state with no obvious change trend.The carbonate binding state of Mn showed an increasing trend and its exchangeable state showed a decreasing trend.(3)The correlation of sediments showed that there were obvious homology between Zn and Cd,Pb and As,Cr and Mn.The geo-accumulation index showed that Cd was extremely serious pollution,Zn was strong-extremely serious pollution,As was moderate-strong pollution,Pb was moderate pollution,Cu was mild-moderate pollution,Cr and Mn were pollution-free.The potential ecological risk index

关 键 词：沉积物 重金属污染 生态风险评价 矿山 广西内苗溪 

分 类 号：X53[环境科学与工程—环境工程]