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

Michigan State University, East Lansing MI

Investigators

Abstract

0329374 Boyd Nitroaromatic 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.