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）。使用杨树是因为有广泛的背景处理这个物种。杂交种H-11-11，大果杨×美洲黑杨，具有良好的栽培和生长特性。这些树木种植在西方化学公司设计的地点，并得到了华盛顿州生态部的同意。在4年的时间里，98-99%的三氯乙烯已从进水中去除。1998年期间，树木没有散发出可检测到的TCE。对种植土壤与对照土壤的分析表明，氯化物的增加相当于添加到细胞中的TCE的量。表明TCE已被广泛矿化。使用四氯化碳和四氯乙烯的结果类似。细菌对TC降解的贡献可以忽略不计。在与我们现场存在的条件相当的条件下，杨树将有助于修复。Mike Hooper博士（项目7）的研究表明，TCE处理过的杨树的碎屑对几种测试的昆虫无害。未来的工作将使用14 C标记的TCE来测量TCE的吸收率和碳的命运。我们还将开发一系列植物，可以在不同的地理区域对各种常见污染物进行解毒。我们还初步成功地引入了降解酶细胞色素P450 IIE 1的基因。这些植物形成了高达35倍的三氯乙烯的第一降解产物。我们正在申请在我们的实地试验场使用它们的许可。我们已经与其他几项研究合作，以获得基因，从而扩大植物可以解毒的化合物的范围。

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.