乙二胺二琥珀酸和柠檬酸对黑土中外源重金属的活化效应  

Effects of EDDS and citric acid on release and mobilization of heavy metals from black soil

作　　者：丁竹红[1] 吴熙[2] 胡忻[3] 尹大强[1] 

机构地区：[1]南京大学环境学院,污染控制与资源化研究国家重点实验室,江苏南京210093 [2]南京工业大学环境科学与工程学院,江苏南京210009 [3]南京大学现代分析中心,江苏南京210093

出　　处：《环境污染与防治》2008年第1期9-12,16,共5页Environmental Pollution & Control

基　　金：污染控制与资源研究国家重点实验室开放研究基金资助项目(No.PCRRF06001);国家自然科学基金资助项目(No.20607010)

摘　　要：通过解吸实验和小麦盆栽实验，研究了生物可降解有机配体乙二胺二琥珀酸（EDDS）、柠檬酸（CIT）对黑土中外源Cu、Cd、Zn和Pb的活化效应。不同浓度EDDS、CIT对黑土中外源重金属解吸实验表明，EDDS对黑土中外源Cu、CA、Zn和Pb的解吸远高于CIT。重金属／EDDS摩尔比为1：1时，4种重金属的解吸率在50．8％～69．2％。小麦盆栽实验表明，EDDS为5mmol／kg时，对小麦幼苗茎叶和根系中重金属含量影响较大，明显导致小麦幼苗茎叶和根系中CA、Cu、Pb和Zn的富集量增加。EDDS处理组Cd、Cu、Pb和Zn的茎叶富集系数远高于对照组和CIT处理组。随时间的增加，EDDS处理缰和CIT处理组重金属的根系富集量均增加，但对照组和CIT处理组大部分重金属14d茎叶富集量略低于7d茎叶富集量。因此，EDDS对黑土中外源重金属有较强的解吸和活化能力，可以较大程度地强化小麦幼苗根系对黑土中外源CA、Cu、Pb和Zn的吸收并诱导这些重金属由根系向茎叶迂移。Effects of [s,s]-ethylenediamine disuccinic acid （EDDS） and citric acid on release and mobilization of heavy metals Cu, Cd, Zn and Pb from black soil were investigated through desorption experiment and pot growth experiment. EDDS was much more effective as a ligand than citric acid to release Cu, Cd, Zn and Pb in the desorption runs. Using EDDS/metal molar ratio of 1, 50.8%-69.2% of the metals in the soil sample were desorbed with Cd desorbed the most. The results of the pot experiments showed that adding 5 mmol/kg EDDS significantly increased the concentration of the four metals in shoots and roots of the wheat seedlings; 7 days and 14 days after the treatment of EDDS, the shoot concentration factors of Cd, Cu, Pb and Zn were much higher than those found in the control and the citric acid runs. The metals in the root samples in all treatments increased with the growing time of the wheat seedlings. Concentrations of the four metals in the shoots continued to increase 7 days after treatment of EDDS; they peaked during the first 7 days after the citric acid treatment. EDDS not only enhanced the root uptake of the metals but also mobilized them from root to shoot of the wheat seedlings.

关 键 词：乙二胺二琥珀酸 柠檬酸 解吸 重金属 植物富集 

分 类 号：X53[环境科学与工程—环境工程] S153.61[农业科学—土壤学]