洞庭湖滩地重金属分布及其生态风险评价  

Distribution and ecological risk assessment of heavy metal elements in soils of the beaches in Dongting Lake

作　　者：李永进[1] 汤玉喜[1] 唐洁[1] 吴敏[1] 

机构地区：[1]湖南省林业科学院,湖南长沙410004

出　　处：《中南林业科技大学学报》2011年第2期55-59,共5页Journal of Central South University of Forestry & Technology

基　　金：国家"十一五"科技支撑项目"江河滩地生态修复与综合治理技术试验示范"(2006BAD03A15)

摘　　要：采用内梅罗综合污染指数和Hakanson潜在生态危害指数法对洞庭湖退田还湖滩地土壤重金属分布特征、污染状况和潜在生态危害进行了评价。结果表明:与湖南省潮土背景值相比较,三个样地的中Pb、Cu、As的含量平均值都超过了背景值,Cd和Cr的含量平均值小于背景值,且Pb的平均含量均是湖南省潮土背景平均值的2倍多;广兴洲样地土壤中6种重金属的平均含量值均高于其他样地;集成垸土壤中的Pb、As和三个样地土壤中Cd重金属含量较易受外界环境因素的影响而波动较大。对重金属间及其与土壤理化性质进行相关性分析可知,Pb与pH有极显著的负相关性,6种金属元素与有机质存在正相关,Pb、Zn、As与全氮也存在一定的正相关,Pb与Zn以及Cu与Cd、Zn、As之间存在极显著的正相关性,Cd与Zn、As以及Cr与As之间存在显著的正相关性。由样地土壤中的重金属污染指数可知,广兴洲样地的土壤重金属污染指数和潜在生态危害系数均比其他样地高,但均属于轻微污染和存在轻微潜在生态危害。The distributions, soil environment status and potential ecological risk of heavy metal were studied in beaches soil of rechange the cropland into lake in Dongting Lake by adopted Nemerow＇s and Hakanson＇s methods. The results show that means of heavy metals in the soil collected from the three beaches were compared with the background values of soil heavy metal in Hunan province, the average content of Pb, Cu, As in the soils of the three beaches were all higher than the background values, and the average content of Cd and Cr were both lower than the background values , and the average content of Pb was more 2 times than the bachground values , and the average of heavy matals in the soils of Guangxingzhou beach were all heigher than the other beaches. In addition, the contents of Pb, As in the soil of Jichengyuan and that of Cd in the three beaches were easier to be affected by the external environment factors and fluctuated considerably. Correlation analysis indicates that Pb with the pH value displayed significant negatively correlation, the 6 heavy metals were correlated with organic matter, Pb, Zn, As were also certainly correlated with total nitrogen Zn with Pb and Cd, Zn,As with Cu were significantly correlated, Zn, As with Cd and Cr with As were positively correlated; by using the Nemerow and Hakanson＇ method of potential eco logical risk assessment, the potential ecological risk of heavy metals were estimated. The result show that integrated pollution indexes and potentially ecological risk indexes of heavy metals in the soils of Guangxingzhou beach were more than the other beaches, but the pollution degree and the potentially ecological risk of heavy metal in the beaches were light.

关 键 词：洞庭湖 滩地 土壤 重金属 潜在生态危害 

分 类 号：X53[环境科学与工程—环境工程]