Phytoremediation of 1,4-Dioxane with Sweet Basil
Authors:Jomar Gonzalo, Jeff Lopez
Mentor:Garrett Struckhoff , Assistant Professor of Civil and Environmental Engineering, California State University, Fullerton
The purpose of this experiment was to observe the phytoremediation of dioxane through uptake by Ocimum basilicum (sweet basil). The first phase of this project involved growing pairs of basil plants in reactors contaminated with a control (0%), low (0.015%), medium (0.15%), and high (1.5%) concentration of dioxane. After 29 days, the plants, roots, and soil were harvested, separately sealed into glass vials, and allowed to equilibrate. Gas chromatography was used to make measurements of the dioxane headspace concentrations in the sealed vials. Using known partitioning constants, the fractions of dioxane in the soil, water, and plants were determined. Overnight oven-drying of the samples was used to find their individual dry/water masses. The results of this experiment indicate that the dioxane removal rate by basil was inversely proportional to dioxane concentration, as expected, with 92% removal observed in the low concentration and 48% in the high. The data also indicate that higher concentrations resulted in plant growth inhibition. These two observations are probably related. One unexpected result was an increased yield in biomass by each plant exposed to low levels of dioxane. The low concentrations may have affected the hydrophobicity of the plant’s roots, causing a stress response and slightly accelerated growth rate. Further investigation is required. This research provides valuable information for future experiments involving phytoremediation of dioxane.