Geochemical controls on bioavailability and toxicity of nitroaromatics during phytoremediation (TSE03-N)

[03:29 . 374]硝基芳香族化合物由于被广泛用作炸药，在美国是最重要的污染物。全国有1200多个地点受到这类化合物的污染，目前缺乏有效和低成本的补救这些地点的方法。本项目将开发一种新的杂交技术，利用大量养分施肥来控制硝基芳香族化合物对植物的生物有效性，用于植物修复。该项目将测试一个假设，即在建立植物修复植物之前，在受污染的土壤上施用钾（K+）将把大多数硝基芳香族污染物隔离在粘土矿物夹层中，在那里，化合物对未成熟的植物既没有毒性，也没有足够的流动性来转移到现场。该项目还将验证一个假设，即一旦植物建立了强健的根系和旺盛的生长，钙离子（Ca2+）在土壤中的应用将以可控的方式从粘土中释放出硝基芳香族化合物，从而允许根系拦截和植物在根际吸收或降解。这项探索性可行性研究将展示一种管理方案的要点，即粘土矿物夹层内的纳米级环境可以在最佳时间吸收和释放污染物化合物。新的管理工具将加强对污染场地硝基芳香族化合物动员的工程控制，并将促进有效的植物修复。

0329374 BoydNitroaromatic compounds are prominent priority pollutants in the United States because of their widespread use as explosives. More than 1200 sites across the country are contaminated with such compounds, and an efficient and low-cost means of remediating these sites currently is lacking. This project will develop a novel hybrid technology that uses macronutrient fertilization to control the bioavailability of nitroaromatic compounds to the plants used in phytoremediation. The project will test the hypothesis that application of potassium (K+) to contaminated soils before establishing phytoremediative plants will sequester most nitroaromatic contaminants in clay mineral interlayers, where the compounds are neither toxic to the immature plants nor mobile enough to move offsite. The project also will test that hypothesis that once the plants have established robust root systems and vigorous growth, application of calcium ions (Ca2+) to the soil will release the nitroaromatic compounds from the clays in a controllable fashion, allowing root interception and plant uptake or degradation in the rhizosphere. This exploratory feasibility study will demonstrate the essentials of a management scheme whereby nanoscale environments within clay mineral interlayers are tailored to both sorb and release the pollutant compounds at optimal times. The new management tool will enhance engineering controls on mobilization of nitroaromatic compounds at polluted sites and will promote effective phytoremediation.