为了了解湿地土壤重金属富集现状,探索其解决途径,为污染防治措施提供科学依据,通过系统调查采样,测试和研究了醴陵官庄湖湿地土壤中3种不同土壤类型(自然土壤、季淹土壤、常淹土壤)0~20cm土壤层中铜(Cu)、锌(Zn)、铅(Pb)、镉(Cd)、和铬(Cr)等重金属的含量。通过Hakanson潜在生态危害指数法、污染负荷指数法,对湿地土壤重金属污染及潜在生态风险进行分析。结果表明:(1)3类土壤中,除自然土壤中的Zn和常淹土壤中的Cr之外,其他重金属含量均值都在不同程度上超过了湖南省土壤背景值,其中自然土壤中的Cd超过了背景值的52.2倍;(2)3类土壤中,Cd都达到了重度污染,Cr处于安全范围,其他3种重金属则在常淹土壤中均达到警戒限;(3)土壤区域污染负荷指数在自然、季淹、常淹土壤中分别是2.42,2.55,2.22,均为中度污染水平,其中Cd的贡献率最大,3类土壤中均达到75%以上;(4)自然土壤的潜在生态危害最严重,达到了429.28,属于强潜在生态风险态势,季淹土壤次之,常淹土壤最低,其中对生态环境造成潜在威胁最大的元素为Cd,达到很强风险程度,其他元素则处于轻度风险程度。由此可见,土壤中的重金属污染已经对醴陵官庄湖湿地的环境维护造成了十分严重的影响,醴陵官庄湖湿地的土壤及周边环境急需综合整治。

In order to understand the current status of heavy metal enrichment in wetland soils,explore the solutions,which will provide a scientific basis for pollution prevention and control measures,through the system investigation,sampling,testing and research the Guanzhuang lake wetland soil in three different soil types (natural soil,seasonal soil,constant flooding soil) 0 ~ 20 cm soil layer of copper (Cu),zinc (zinc),lead (Pb),cadmium (Cd),chromium (Cr) and the content of heavy metal.Through Hakanson potential ecological hazard index method,pollution load index,heavy metal pollution of wetland soil and potential ecological risk were analyzed.The results showed that(1)in the three types of soil,except for Zn in the natural soil and Cr in the frequently flooded soil,the average content of other heavy metals exceeded the background value of the soil in Hunan province to varying degrees,and Cd in the natural soil exceeded 52.2 times of the background value.(2)in the three types of soil,Cd reaches the level of heavy pollution,Cr is in the safe range,and the other three heavy metals reached the warning limit in the constantly flooded soil.(3)the regional pollution load index of soil was 2.42,2.55 and 2.22 in natural,seasonal and often flooded soil,respectively,which were all moderate pollution levels.The contribution rate of Cd is the largest,reaching more than 75% in all three types of soil.(4)the potential ecological hazard of natural soil is the most serious,reaching 429.28,belonging to the situation of strong potential ecological risk,followed by seasonal flooding,and the lowest under constant flooding.Among them,Cd is the element that poses the greatest potential threat to the ecological environment,reaching a high risk level,while other elements are at a slight risk level.It can be seen that heavy metal pollution in the soil has caused a very serious impact on the environmental maintenance of Guanzhuang lake wetland in Liling.The soil and surrounding environment of LilingGuanzhuang lake wetland urgently need comprehensive improvement.