皂苷与EDTA复合淋洗污染塿土中Cu、Pb的效果研究  

Leaching of Copper and Lead in Contaminated Lou Soil with Combined Saponin and EDTA

作　　者：邓红侠[1] 李珍[1] 杨亚莉[1] 许岩[1] 杨亚提[1] 

机构地区：[1]西北农林科技大学理学院,陕西杨凌712100

出　　处：《农业环境科学学报》2015年第3期461-470,共10页Journal of Agro-Environment Science

基　　金：陕西省农业科技攻关计划项目(2014K02-12-02)

摘　　要：采用振荡和柱淋洗方法,选用生物表面活性剂皂苷和螯合剂乙二胺四乙酸二钠盐(EDTA)作淋洗剂,研究了EDTA、皂苷及其复合液对污染塿土中重金属Cu、Pb的淋洗效果,并比较不同淋洗剂淋洗前后重金属的形态变化特征。结果表明:EDTA浓度为0.5、1.0 mmol·L-1时与不同质量浓度皂苷复合振荡淋洗Cu、Pb时表现为协同作用,对Pb的协同作用尤为明显;EDTA浓度大于5.0mmol·L-1时,与不同质量浓度皂苷复合淋洗Cu、Pb表现为拮抗作用。1.0 mmol·L-1EDTA、50 g·L-1皂苷及其复合淋洗液(1.0 mmol·L-1EDTA与50 g·L-1EDTA)对土柱中Cu、Pb的累积淋洗量均随着淋洗液体积的增大而逐渐增加;1.0 mmol·L-1 EDTA与50 g·L-1皂苷复合淋洗土柱中Cu时表现为协同作用,其对单一及复合污染塿土中Cu的累积淋洗百分率分别为23.59%和21.57%,对Pb的累积淋洗百分率分别为27.59%和24.92%。柱淋洗前后重金属形态分级结果表明,EDTA、皂苷及其复合淋洗液能有效去除碳酸盐结合态、有机结合态和硫化物残渣态重金属Cu、Pb;EDTA与皂苷及其复合淋洗液可显著活化污染塿土中的重金属Cu、Pb,有望与植物修复技术联用修复重金属污染塿土。In this experiment, leaching of Cu and Pb in their singly or combinedly contaminated Lou soil was studied by chelating agent ethylenediaminetetraacetic acid disodium salt(EDTA) and biosurfactant saponin in single or mixed solution, using batch shaking and soil column leaching method. Characteristics of Cu and Pb fractions were compared before and after leaching. In batch shaking test, synergistic effects on Cu and Pb leaching in contaminated Lou soil were observed in different concentrations of saponin solution combined with EDTA(0.5 mmol·L-1or 1.0 mmol·L-1). The percentages of Pb leaching were higher than those of Cu. However, antagonistic effects on metal leaching were found at EDTA concentrations higher than 5.0 mmol·L-1. In soil column leaching test, cumulative amounts of Cu and Pb leaching in contaminated Lou soil columns increased gradually with increasing cumulative volume of leaching agents at 1.0 mmol·L-1EDTA or 50 g·L-1saponin and their mixture. In mix leaching of 1.0 mmol·L-1EDTA and 50 g·L-1saponin, the synergistic effects on Cu leaching was observed and the cumulative leaching percentage of Cu was 23.59% and 21.57% for singly and combinedly metals contaminated Lou soils, respectively, while that of Pb was 27.59% and 24.92%, respectively. Carbonate, organic, and sulfide residual fractions of Cu and Pb were effectively leached by 50 g·L-1saponin, 1.0 mmol·L-1EDTA and their mixture, demonstrating their significant activating effects on Cu and Pb in contaminated Lou soil. Saponin and EDTA leaching agents in combination with phytoremediation technology could be used to remediate Cu and/or Pb contaminated Lou soil.

关 键 词：EDTA 皂苷 铜 铅 污染塿土 淋洗 修复 

分 类 号：X53[环境科学与工程—环境工程]