PHYTOREMEDIATION OF TOXIC WASTE SITES

该计划的目的是探索使用植物来修复环境中的有毒溶剂泄漏，特别是三氯乙烯(TCE)。杨树被使用，因为有一个广泛的背景处理本种。三果杨杂交组合H-11-11具有良好的栽培和生长特性，可作为选育材料。这些树是在西方化学公司设计的地点种植的，并得到了华盛顿州生态部的同意。在4年的时间里，从进水中去除了98-99%的三氯乙烯。在1998年期间，树木没有检测到三氯乙烯。对种植的土壤与对照的分析表明，氯化物的增加相当于添加到细胞中的三氯乙烯的量。表明三氯乙烯已被广泛矿化。使用四氯化碳和全氯乙烯也得到了类似的结果。细菌对TC降解的贡献可以忽略不计。在与我们现场现有条件相当的条件下，杨树将有助于补救。与Mike Hooper博士(项目7)的研究表明，三氯乙烯处理杨树的碎屑对几种测试的昆虫是无害的。未来的工作将使用14C标记的TCE来测量TCE的吸收速度和碳的去向。我们还将开发一系列植物，这些植物可以为不同地理区域的各种常见污染物解毒。我们还初步成功地引入了一种降解酶--细胞色素P450 IIE1的基因。这些植物形成了高达35倍于三氯乙烯第一次降解产物的量。我们正在申请许可，以便在我们的现场测试现场使用它们。我们已经与其他几项研究合作，以获得将拓宽植物解毒化合物范围的基因。

The purpose of this program is to explore the use of plants to remediate toxic solvent spills, especially trichloroethylene (TCE), in the environment. Poplars were used as there is an extensive background dealing with this species. The hybrid H-11-11, Populus trichocarpa X P. deltoides, was used as it has favorable cultivation and growth characteristics. The tress were planted at a site designed by Occidental Chemical Corporation with concurrence of the Washington State Department of Ecology. Over the 4-year period 98-99% of the TCE has been removed from the influent water. During 1998 there was no detectable TCE transpired by the trees. Analysis of the planted soil versus controls showed an increase in chloride that was equivalent to the amount of TCE added to the cells. indicating that the TCE has been extensively mineralized. Comparable results were found using carbon tetrachloride and perchloroethylene. The contribution of bacteria to the degradation of the TC was negligible. Under conditions comparable to what exists at our site, poplars will be useful for remediation. Studies with Dr. Mike Hooper (Project #7) have indicated that the detritus from TCE treated poplars is harmless to several insects tested. Future work will use 14C-labeled TCE to measure the rate of uptake and the fate of the carbon of TCE. We will also develop a repertoire of plants that can detoxify a variety of common pollutants in a variety of geographic areas. We have also had preliminary success with the introduction of genes for a degradative enzyme, cytochrome P450 IIE1. These plants formed up to 35 times as much of the first degradative product of TCE. We are in the process of applying for permission to use them at our field test site. We have entered into collaborations with several other investigations to obtain genes that will broaden the range of compounds that can be detoxified by plants.