福建沿海农田土壤重金属污染与潜在生态风险研究  

Heavy Metal Pollution and Potential Ecological Risk of Paddyfield Soil in Littoral Area,Fujian Province

作　　者：陈迪云[1] 谢文彪[1] 宋刚[1] 罗定贵[1] 张鸿郭[1] 杨军华 

机构地区：[1]广州大学环境科学与工程学院,广东广州510006 [2]福建省地质调查研究院,福建福州350000

出　　处：《土壤通报》2010年第1期194-199,共6页Chinese Journal of Soil Science

基　　金：国土资源部农业地质与生态地球化学调查项目(200314200024)资助

摘　　要：分析了取自福建沿海农田185件表层土壤样品的重金属含量与分布特征,采用连续提出的方法研究重金属元素的赋存状态。结果表明福建沿海稻田土壤中的Hg、Cd、As、Cr、Ni、Cu、Zn和Pb的平均含量分别为0.41mgkg-1、0.20mgkg-1、6.62mgkg-1、35.65mgkg-1、12.7mgkg-1、128.39mgkg-1、109.65mgkg-1和63.56mgkg-1。相对于区域土壤背景值与国家土壤环境质量标准,污染较突出的元素是Hg和Cd。有46%样品中的Hg含量高于土壤质量的Ⅱ标准值,有13%的样品的Cd高于土壤质量的Ⅱ标准值。Hg高含量的样品主要分布福州、漳州等城镇等附近,同时它在土壤中主要以有机结合态的形式存在,土壤中Hg含量的升高可能主要来自于后期污染的叠加。Cd高含量的样品的分布则较分散,并不都集中在工业活动区,同时它在土壤中是以残渣态和铁锰氧化物态的形式存在,说明其高含量可能更多是受到成土母质的地球化学背景影响。农田土壤中的Hg和Cd具有较高的生态风险。该区主要是栽种水稻,而水稻对Cd具有强吸收的特性,土壤酸化还会促进Cd的吸收。本区土壤呈酸性,所以Cd污染可能导致大米的食品安全应引起足够重视。Concentrations of Hg,Cd,As,Cr,Ni,Cu,Zn and Pb were measured in 185 paddy soil samples collected from 10 valleys in Fujian Littoral area,Fujian Province,in order to assess the pollution and distribution of these heavy metals.According to the Tessier sequential chemical extractions,the speciation of Heavy metals in the soils were assessed.The results showed that mean contents of Hg,Cd,As,Cr,Ni,Cu,Zn and Pb in Paddy soil samples were 0.41,0.20,6.62,35.65,12.7,128.39,109.65 and 63.56 mg kg,respectively.Compared to the background values for soils in Fujian Province,Hg and Cd were the strongest enriched elements.These were 46% samples which had Hg content and 13% samples which had Cd content higher than the standard Ⅱof soil quality.The samples with higher Hg content were distributed around city or town such as Fuzhou,Zhangzhou and Hg was mainly in organic phase.These characters showed that higher content of Hg was due to the pollution of economic activity.Whereas the samples with higher Cd content did not limited in the area of economic activity,and Cd in the soils mainly existed in residual phase and Fe-Mn oxides.The higher contents of Cd sould be lied on the geochemistry background of the rocks.Cd and Hg in paddy soil possessed higher potential ecological risk and rice has a characteristic of strongly absorbing Cd.Moreover acidification could increase this absorbency.The soils in this area were acidic,so the food safety resulted from Cd pollution need to be noticed.

关 键 词：农田土壤 Cd、Hg污染 生态风险 福建沿海 

分 类 号：X53[环境科学与工程—环境工程]