利用生物可降解螯合剂[S，S]-乙二胺二琥珀酸浸提沉积物中重金属的影响因素研究  

Factors Affecting the Extraction of Heavy Metals in Sediments Using Biodegradable [S,S]-ethylene diamine disuccinic acid

作　　者：罗璐瑕[1] 胡忻[2] 

机构地区：[1]河海大学环境科学与工程学院,江苏南京210098 [2]南京大学现代分析中心,江苏南京210093

出　　处：《农业环境科学学报》2008年第3期932-936,共5页Journal of Agro-Environment Science

基　　金：水文水资源与水利工程科学国家重点实验室开放研究基金(2005407111);国家自然科学基金(20607010)

摘　　要：近年来,螯合剂[S,S]-乙二胺二琥珀酸因具有良好的生物降解性及较强的金属螯合能力在重金属污染土壤淋洗修复和诱导植物修复等方面运用受到广泛关注。但[S,S]-乙二胺二琥珀酸应用于沉积物中重金属提取的研究较少。本文通过分批提取实验研究了[S,S]-乙二胺二琥珀酸提取水系沉积物中Cu、Zn、Cd和Pb的影响因素如提取时间、pH、螯合剂量、固液比等的效应。结果表明,沉积物的4种重金属[S,S]-乙二胺二琥珀酸提取的最佳提取时间因元素及土壤特性有差异,但提取时间24h4种金属都能得到较好的提取率。重金属的螯合提取率无显著的pH依赖性。固液比对4种重金属的提取率无明显影响。沉积物重金属与螯合剂化学剂量的摩尔比增大能提高重金属的提取率。根据成本效益原则,24h提取时间、中性范围pH和大于1的螯合剂与沉积物中重金属化学剂量的摩尔比建议可作为[S,S]-乙二胺二琥珀酸提取沉积物中重金属的合适条件。A biodegradable chelating agent, [S,S]-stereoisomer of ethylenediamine disuccinate （[S,S]-EDDS）, has been investigated as a potential washing/leaching agent to replace ethylenediaminetetraacetic acid for the extraction of heavy metals from contaminated soils and sediments in recent years, but few studies have been reported on the controlling factors during the extraction. In this study, factors affecting the extraction of heavy metals in sediments using [S,S]-EDDS was studied through batch extraction experiments. The time required to achieve maximum metal extraction from the sediments was different among extracted heavy metals, however, 24 h could get a compromise higher ex- traction efficiency for the extracted metals. Extraction solution pH was not the dominant factor governing the release of Cu, Zn, Cd and Pb from sediments when chelating agent was used. The extractable percentage of heavy metals under different solid-liquid ratios showed no significant difference at neutral pH. The increase of stoichiometric molar ratios of chelator to extracted heavy metals could improve the metal extraction efficiency at neutral pH. But higher ratio of chelator to metal would leach more mineral elements from sediments. According to the cost efficiency, it was suggested that the compromise experimental conditions were 24 h extraction time, neutral pH, and above 1 of the stoichiometric molar ratios of chelator to extracted heavy metals.

关 键 词：沉积物 重金属 [S S]-乙二胺二琥珀酸 浸提 

分 类 号：X830.2[环境科学与工程—环境工程]