简化连续提取法评价污染土壤中Zn、Cd的植物有效性  

Evaluation of Phytoavailability of Zinc and Cadmium in Contaminated Soils by a Short Sequential Extraction Procedure

作　　者：闭向阳[1] 杨元根[1] 冯新斌[1] 李非里[1] 孙力[1] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室

出　　处：《环境科学》2006年第4期770-774,共5页Environmental Science

基　　金：中国科学院和贵州省'西部之光'项目;国家自然科学基金项目(40473049);中国科学院知识创新工程重要方向项目(KZCX3-SW-443)

摘　　要：以0.01 mol.L-1CaCl2和0.005 mol.L-1DTPA作为提取剂,用简化的3步连续提取法对贵州省赫章县土法炼锌污染土壤中Zn、Cd的形态进行了分析.结果显示,污染土壤中Zn、Cd主要以残渣态的形式存在,CaCl2提取态和DTPA提取态Zn、Cd平均仅占全量的0.63%、3.91%和10.94%、10.13%.土壤中不同形态Zn、Cd含量与玉米中Zn、Cd含量的相关分析结果显示,CaCl2提取态金属与玉米中金属含量没有显著的相关关系,而DTPA提取态、残渣态以及总量Zn、Cd与玉米根、茎叶中Zn、Cd含量显著正相关.这些结果表明CaCl2提取态Zn、Cd对土壤中该元素的植物有效态可能不具重要贡献,而DTPA提取态金属和金属总量在一定程度上能作为评价土壤中元素植物有效性的标准.Cultivated soils and maize samples from heavy metal contaminated locations affected by zinc smelting activities were collected in Hezhang County, Guizhou Province. Chemical fractions of zinc and cadmium （extracted by 0.01 mol· L^-1 CaCl2 and 0.005 mol· L^-1 DTPA） were evaluated by using a short three-step sequential extraction procedure. Results showed that Zn and Cd in soil were dominated by residual fraction, while the CaCl2 extractable and DTPA extractable fraction are only accounted for 0.63%, 3.91% for Zn, and 10.94%, 10.13%for Cd, respectively. Correlation analyses demonstrated that soil CaCl2 extractable metals were not correlated with maize metal concentrations, whereas the DTPA extractable fraction, residual fraction and total Zn and Cd concentrations were correlated significantly with the metal concentrations in maize roots, stems and leaves. These results indicated that CaCl2 extractable fraction may not pay important role on metal phytoavailahility in the studied soils. While DTPA extractable fraction and total metal concentrations can be employed to evaluate metals phytoavailahility.

关 键 词：ZN CD 污染土壤 玉米 连续提取 植物有效性 

分 类 号：X53[环境科学与工程—环境工程]