摘要
【目的】普者黑流域拥有独特的自然景观和特殊的岩溶湖泊生态系统,研究其湖泊沉积物中重金属分布特征及生态风险评价对该区域湖泊水环境保护及污染防治具有重要意义。【方法】采用地累积指数和潜在生态风险指数分析了流域内表层水及沉积物中6类重金属:砷(As)、铬(Cr)、铜(Cu)、锌(Zn)、锰(Mn)和镍(Ni)水平,并对重金属生态风险进行评价及源头追溯。【结果】(1)普者黑流域表层水中重金属质量浓度远低于《地表水环境质量标准》Ⅰ类标准限值。(2)沉积物中重金属的平均质量分数均高于其对应的背景值(Cr除外)。(3)沉淀物重金属质量分数平均值从大到小依次为Mn、Zn、Cu、Cr、Ni、As,分别是各自背景值的1.68、1.33、3.33、0.96、1.01和1.59倍。其中Cr污染程度最低,有96.6%的采样点为清洁水平;As偏中度污染,是Mn的1.8倍;Mn的清洁水平和轻度污染相当。(4)单项重金属生态风险指数从大到小依次为As、Cu、Ni、Cr、Mn、Zn,潜在生态风险指数值均小于40,风险较低。【结论】As和Cu是普者黑流域污染范围最大、程度最高的2类重金属,Cr、Ni和Zn大多为无污染;潜在生态风险评价发现:平均生态风险指数为31.7,As和Cu贡献率最大,所有重金属均处于低生态风险;从空间分布来看,流域下段国家湿地公园及3条入湖河流是各类重金属主要汇集区域。图6表7参40。
[Objective]Puzhehei watershed has a unique natural landscape and a special karst lake ecosystem.This study aims to investigate the distribution characteristics of heavy metals in lake sediments and make ecological risk assessment,which is of great significance to the protection and pollution control of lake water environment in the region.[Method]The levels of six types of heavy metals(As,Cr,Cu,Zn,Mn,and Ni)in surface water and sediments in the basin were analyzed by geo-accumulation index evaluation and potential ecological risk index,and ecological risks of heavy metals were evaluated and the source was traced back.[Result](1)The mass concentration of heavy metals in the surface water of Puzhehei Basin was far below the ClassⅠstandard limit of"Surface Water Environmental Quality".(2)The average mass fraction of heavy metal in the sediments was higher than their corresponding background values(except Cr).(3)The average value of heavy metals in the sediments detected was Mn,Zn,Cu,Cr,Ni and As in descending order,which were 1.68,1.33,3.33,0.96,1.01 and 1.59 times of their background values,respectively.The pollution degree of Ni was the lowest,with 96.6%of the sampling points being clean.As was moderately polluted,which was 1.8 times of Mn,and the clean level of Mn was similar to that of light pollution.(4)The ecological risk index of individual heavy metal in descending order was As,Cu,Ni,Cr,Mn and Zn,and the potential ecological risk index values were all less than 40,indicating low risk.[Conclusion]As and Cu are the two heavy metals with the largest pollution range and the highest degree in Puzhehei watershed,while Cr,Ni and Zn are mostly pollution-free.In the potential ecological risk evaluation,the average ecological risk index is 31.7.As and Cu contribute most to this risk,and all heavy metals are at low ecological risk.From the perspective of spatial distribution,the National Wetland Park in the lower reaches of the river basin and the estuaries of the three rivers are the main gathering areas of heavy metals.[Ch,6 fig.7 tab.40 ref.].
作者
彭博
刘鹏
王妍
张叶飞
杨波
PENG Bo;LIU Peng;WANG Yan;ZHANG Yefei;YANG Bo(College of Ecology and Environment,Southwest Forestry University,Kunming 650224,Yunnan,China;Research Institute of Stony Desertification,Southwest Forestry University,Kunming 650224,Yunnan,China)
出处
《浙江农林大学学报》
CAS
CSCD
北大核心
2021年第4期746-755,共10页
Journal of Zhejiang A&F University
基金
国家自然科学基金资助项目(31660139,31760245)。
关键词
普者黑
沉积物
重金属
地累积指数
潜在生态风险
Puzhehei
sediments
heavy metal
geo-accumulation index
potential ecological risk
