PHYTOREMEDIATION OF METAL-CONTAMINATED SOIL BY SORGHASTRUM NUTANS AND ARBUSCULAR MYCORRHIZAL FUNGI

Heavy metals, such as lead (Pb) are commonly present in urban soils because of various anthropogenic sources. Phytoextraction, a subset of phytoremediation, is a technique that uses plants to absorb and concentrate pollutants. Unfortunately, some metals, such as Pb, are less likely to be bioavailable or treated by phytoextraction. The addition of soil amendments such as EDTA have been shown to increase metal bioavailability and uptake, but environmental concerns exist surrounding its low biodegradability. Phytoextraction with the addition of arbuscular mycorrhizal fungi is an evolving method that can be used to remediate contaminated sites. Arbuscular mycorrhizal fungi are biotrophs that establish mycorrhizae, or symbiotic relationships between plants and fungi. In these relationships, fungi colonize the plant roots to provide a new pathway for the uptake of low mobility nutrients in soil, such as nitrogen, phosphorous, and micronutrients. The objective of this study is to determine the effects arbuscular mycorrhizal fungi have on the phytoextraction of metal-contaminated soil using Sorghastrum nutans. Pots containing homogenized soil spiked with Pb and Sorghastrum nutans seedlings have been prepared. The first pot from each set of Pb concentrations will be inoculated with 2 grams of mycorrhizal fungi, and the second with 4 grams of mycorrhizal fungi. After a 16 week growing period, the soil, roots, shoots, and leaves of each pot will be subsampled. Plant tissue samples will be digested following EPA SW 846 Method 3050B. Samples will then be analyzed using inductively coupled plasma-optical emission spectroscopy for Pb to evaluate the potential effectiveness of this approach for soil Pb remediation.