Effects of nano-sized zero-valent iron (nZVI) on DDT degradation in soil and its toxicity to collembola and ostracods
Effects of nano-sized zero-valent iron (nZVI) on DDT degradation in soil and its toxicity to collembola and ostracods
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DOI：
10.1016/j.chemosphere.2013.02.039
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发表时间：
2013-06-01
期刊：
影响因子：
8.8
通讯作者：
Joner, Erik J.
中科院分区：
文献类型：
--
作者：
El-Temsah, Yehia S.;Joner, Erik J.
研究了纳米零价铁（nZVI）原位修复污染土壤和地下水。然而，人们对它对土壤和水生生态系统中的生物的影响知之甚少。研究了纳米零价铁对DDT降解的影响及其对弹尾目（Folsomia candida）和介形类（Heterocypris incongruens）的生态毒理效应。在悬浮培养实验中使用了两种土壤，分别为7 d和30 d：加标（20 mg DDT kg（-1））的桑迪土壤和老化（>50年）的DDT污染土壤（24 mg DDT kg（-1））。将这些样品与1或10 g nZVI kg（-1）一起孵育，并使用弹尾目或介形虫的生态毒理学试验测试土壤和水相中的残留毒性。一般情况下，除了任何浓度的nZVI土壤导致约50%的降解DDT在加标土壤在7和30 d的培养结束时，而DDT的降解较少，在老年DDT污染的土壤（24%）。严重的负面影响的nZVI观察到两个测试生物体7天孵育后，但延长孵育导致氧化的nZVI，降低其对测试生物体的毒性作用。另一方面，DDT对跳虫的繁殖和介形虫的发育有明显的负面影响。结果表明，1 g nZVI kg（-1）对DDT在土壤中的降解效果较好，而对土壤中的老化污染物则需要较高的浓度。nZVI对测试生物体的不利影响似乎是暂时的，并且在氧化后减少。(C)2013爱思唯尔有限公司保留所有权利。
Nano-sized zero valent iron (nZVI) has been studied for in situ remediation of contaminated soil and ground water. However, little is known about its effects on organisms in soil and aquatic ecosystems. In this study, the effect of nZVI on degradation of DDT and its ecotoxicological effects on collembola (Folsomia candida) and ostracods (Heterocypris incongruens) were investigated. Two soils were used in suspension incubation experiments lasting for 7 and 30 d; a spiked (20 mg DDT kg(-1)) sandy soil and an aged (>50 years) DDT-polluted soil (24 mg DDT kg(-1)). These were incubated with 1 or 10 g nZVI kg(-1), and residual toxicity in soil and the aqueous phase tested using ecotoxicological tests with collembola or ostracods. Generally, addition of either concentration of nZVI to soil led to about 50% degradation of DDT in spiked soil at the end of 7 and 30 d incubation, while the degradation of DDT was less in aged DDT-polluted soil (24%). Severe negative effects of nZVI were observed on both test organisms after 7 d incubation, but prolonged incubation led to oxidation of nZVI which reduced its toxic effects on the tested organisms. On the other hand, DDT had significant negative effects on collembolan reproduction and ostracod development. We conclude that 1 g nZVI kg(-1) was efficient for significant DDT degradation in spiked soil, while a higher concentration was necessary for treating aged pollutants in soil. The adverse effects of nZVI on tested organisms seem temporary and reduced after oxidation. (C) 2013 Elsevier Ltd. All rights reserved.