摘要
调查湘南某铅锌矿区周围的菜园土和水稻土Pb、Cd、Cu和Zn的形态分布及其生物活性和迁移性。结果表明：两种土壤中Pb、Cd、Cu和Zn的总量分别超过国家土壤环境质量相应的标准。运用Tessier连续提取法研究发现,土壤中Pb、Cd、Cu和Zn的各形态含量之和与其总量非常的接近,其中菜园土Pb的提取率为96.3%,Cd的为94.1%,Cu的为93.4%和Zn的为91.7%;水稻土Pb的为97.6%,Cd的为92.0%,Cu的为92.1%和Zn的为91.7%,表明该形态分析方法的结果是合理的。土壤中Pb、Cd、Cu和Zn各形态的分布存在很大的差别,残渣态是主要形态,其中Pb的含量占60.7%-58.2%,Cd的是50.4%-59.2%,Cu的是37.3%-53.4%,Zn的是54.9%-46.9%,而交换态所占的比例最小。菜园土重金属的生物活性系数的大小是：Cd〉Cu〉Pb〉Zn,迁移能力的顺序是Cd〉Cu〉Zn〉Pb;水稻土重金属的活性大小和迁移能力的顺序都是：Cd〉Pb〉Zn〉Cu。菜园土重金属的生物活性和迁移性较水稻土的大,其中Cd的生物活性和迁移性的最大。研究结果将为评估矿区污染土壤中重金属的危害提供科学依据。
Fraction distributions, availabilities and mobilities of Pb, Cd, Cu, and Zn in both contaminated soils collected from lead/mine mine area in southern Hunan were investigated. The results showed that the total concentrations of Pb, Cd, Cu, and Zn exceeded the maximum permissible limits set by State Environmental Protection Agency （SEPA） for soils in China, indicating that both soils seriously suffered from heavy metal contamination. The extraction percentages of Pb, Cd, Cu, and Zn with Tessier＇s sequential extraction procedures were 96.3%, 94. 1%, 93.4%, and 91.7% from garden soil, and 97.6%, 92.0%, 92. 1%, and 91.7% from paddy soil, respectively. The sums of each fraction of heavy metal were in agreement with the total contents of heavy metals, which mean that the fraction distributions of heavy metals in the both soils analyzed by Tessier＇s method were reasonable. There were significant differences in fraction distributions of heavy metals in both contaminated soils. Further, the residual fraction was the predominant fraction with 60.7%-58.2% for Pb, 50.4%-59.2% for Cd, 37.3%-53.4% for Cu, 54.9%-46.9% for Zn in both contaminated soils. However, the proportions of exchangeable fractions were the lowest among all fractions. The availabilities and mobilities of heavy metals in garden soil followed Cd 〉 Pb 〉 Zn 〉 Cu, and Cd 〉 Pb 〉 Zn 〉 Cu, respectively, and in paddy soil were Cd 〉 Pb 〉 Zn 〉 Cu. The availabilities and mobilities of heavy metals in garden soil were higher than those in paddy soil, especially, the highest proportions of availability and mobility of Cd were found among all metals in both soils. The results will provide the scientific bases for assessment of harm of heavy metals in contaminated soils around mine.
出处
《生态环境》
CSCD
北大核心
2007年第3期807-811,共5页
Ecology and Environmnet
基金
国家自然科学基金项目(20677080)
关键词
生物活性
污染土壤
形态分布
重金属
迁移性
TESSIER连续提取法
availability
contaminated soil
fraction distribution
heavy metals
mobility
Tessier＇s sequential extraction procedure
