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

0329374芳香族硝基化合物是美国突出的优先污染物，因为它们被广泛用作炸药。全国有1200多个地点受到此类化合物的污染，目前缺乏有效和低成本的补救手段。该项目将开发一种新的杂交技术，利用大量营养素施肥来控制用于植物修复的植物对硝基芳香化合物的生物利用度。该项目将检验这样一种假设，即在建立植物修复工厂之前，在受污染的土壤中应用钾(K+)可以将大多数硝基芳香污染物隔离在粘土矿物夹层中，这些化合物对未成熟的植物既不有毒，也不具有足够的流动性，可以转移到异地。该项目还将检验这一假设，即一旦植物建立了强大的根系和旺盛的生长，向土壤施加钙离子(Ca~(2+))将以可控的方式从粘土中释放硝基芳香化合物，允许根被截留，植物在根际吸收或降解。这项探索性的可行性研究将展示管理方案的要点，根据该方案，粘土矿物夹层内的纳米环境被量身定做，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地点硝基芳香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.