GLDA及其组合试剂对土壤中As、Cd、Cu和Pb的提取能力和机制  

Abilities and Mechanisms of GLDA and Its Combined Complexing Agents to Extract As,Cd,Cu and Pb from Soil

作　　者：陈春发 泮芝伟 侯建国 冯宏亮 仓龙[2] 王玉军[2] CHEN Chunfa;PAN Zhiwei;HOU Jianguo;FENG Hongliang;CANG Long;WANG Yujun(Zhejiang Geological Prospecting Institute of China Chemical Geology and Mine Bureau,Hangzhou 310000,China;Key Laboratory of Soil and Sustainable Agriculture,Chinese Academy of Sciences,Nanjing 211135,China)

机构地区：[1]中化地质矿山总局浙江地质勘查院,杭州310000 [2]土壤与农业可持续发展重点实验室(中国科学院),南京211135

出　　处：《土壤》2024年第4期841-848,共8页Soils

基　　金：中化地质矿山总局污染土壤修复技术研发及应用团队建设项目(ZHTD202105);国家重点研发计划项目(2022YFD1700805)资助。

摘　　要：以重金属复合污染土壤为研究对象,将谷氨酸二乙酸四钠(GLDA)和其他生物可降解络合剂进行组合,研究了单一和组合试剂对土壤中不同重金属的提取效率和影响机制。结果表明:随着试剂与土壤重金属摩尔比的增加,重金属的提取率逐渐增加,最优摩尔比为5∶1;草酸(OA)对As、柠檬酸(CA)对Cu的提取能力高于乙二胺四乙酸二钠(EDTA)对As和Cu的提取能力;GLDA在偏酸的条件下对各种重金属的提取能力均较高;通过不同试剂的组合,GLDA和OA在摩尔比为1∶1时对土壤中As、Cu和Pb的提取能力最强,分别为52.4%、75.0%和89.8%,各重金属元素提取能力顺序为Pb>Cu≈Cd>As。而GLDA和CA在摩尔比为5∶1时对土壤中Cd的提取能力最强,为95.7%。提取前后的土壤重金属形态分级表明,GLDA+OA(1∶1)组合试剂降低了绝大多数形态的重金属含量,减少了易迁移和易被生物吸收的弱结合态重金属含量。In this study,heavy metals combined polluted soil was taken as the study object,and N,N-bis(carboxymethyl)-tetrasodium salt(GLDA)and other biodegradable chelators were combined to explore the extraction efficiency and influence mechanism of single and combined reagents on different heavy metals from soil.The results showed that with the increase of the molar ratio of reagents to heavy metals,the extraction rates of heavy metals increased gradually,and the optimal molar ratio was 5∶1.The abilities of oxalic acid(OA)to extract As and citric acid(CA)to extract Cu were close to those of ethylenediaminetetraacetic acid disodium(EDTA)to extract As and Cu.GLDA had higher extraction abilities for various heavy metals under acidic conditions.With the combination of different reagents,GLDA and OA had the strongest extraction abilities of As,Cu and Pb in soil when the molar ratio was 1∶1,which was 52.4%,75.0%and 89.8%,respectively.The order of extraction ability was Pb>Cu≈Cd>As.While GLDA and CA had the strongest extraction ability of Cd in soil when the molar ratio was 5∶1,which was 95.7%.The chemical fractions of heavy metals before and after extraction showed that GLDA+OA(1∶1)reduced the contents of heavy metals in most chemical fractions,especially the weakly bound heavy metals that are easily transported and absorbed by organisms.

关 键 词：谷氨酸二乙酸四钠 生物可降解络合剂 AS CD CU PB 

分 类 号：X53[环境科学与工程—环境工程]