土壤颗粒态有机质中铜和铅的结合特征  

Binding characteristics of copper and lead in soil particulate organic matter.

作　　者：王丽平[1] 郑顺安[1] 章明奎[1] 

机构地区：[1]浙江大学环境与资源学院土水资源与环境研究所,浙江杭州310029

出　　处：《浙江大学学报（农业与生命科学版）》2007年第6期667-670,共4页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：国家自然科学基金资助项目(40471064);国家重点基础研究发展计划"973"资助项目(2005CB121104)

摘　　要：为了解土壤颗粒态有机质(POM)中重金属的富集机理,采用化学试剂选择提取方法,把POM中铜和铅分为可交换态、络合态、有机质紧结合态和矿质态等4种形态.结果表明,与细土(<0.05 mm)相比,POM中铜和铅的有机质紧结合态、可交换态和络合态比例较高;可交换态重金属比例随POM粒径减小而下降,络合态重金属比例却随POM粒径减小而增加.污染土壤中分离获得的POM有较高比例有机质紧结合态铜和铅,而人为添加的铜和铅在POM中主要向络合态和交换态转化.研究认为,污染土壤中有机质紧结合态重金属大多可能是经植物吸收进入土壤后分解残留所致;而POM中络合态和交换态重金属主要通过有机质与土壤重金属的交换和络合作用而富集.In order to understand the enrichment mechanism of heavy metals in soil particulate organic matter （POM）, four chemical species of Cu and Pb in the POM, including exchangeable, complex, organic tightly bound and mineral bound, were characterized by chemical selective extraction. As compared with 〈0.05 mm soil fraction, the POM had higher percentages of exchangeable, complex, organic tightly bound Cu and Pb. The percentage of the metals as exchangeable form decreased with decreasing size of the POM, while that of complex metals increased with decreasing size of the POM. There was a greater percentage of organic tightly bound Pb and Cu in the POM separated from polluted soils. However, additive Cu and Pb was mainly transformed into complex and exchangeable forms. It was suggested that enrichment of the metals in the POM not only could be residue after selective decomposition of plant residues which contained high concentrations of the metals, but also be formed through complex and exchangeable reactions between metals and the POM.

关 键 词：土壤颗粒态有机质 铜 铅 络合作用 富集机理 

分 类 号：S153[农业科学—土壤学]