Bioavailability and Phytoremediation of Mercury Contaminated Soils.
Fengxiang Han, Yi Su, and David Monts. Mississippi State Univ, DIAL, 205 Research Blvd, Starkville, MS 39759
Mercury contamination is ubiquitous in the Y-12 watershed of Oak Ridge, TN and has been identified as a key contaminant in soil, sediment, surface water, groundwater, buildings, drains, and sumps. The source of the Hg is from elemental Hg used during the 1950s and early 1960s for the manufacture of nuclear weapons. Additionally, more than 70 US DOE sites have Hg-contaminated wastes and hence potentially have mercury in their ecosystems. The objectives of this study were to study bioavailability of various mercury forms in soils/sediments and apply phytoremediation to mercury contamination in soil and to study the phytoremediation process, including metal uptake, translocation, sequestration, complexation, etc., by microscopy, chemical analysis, and spectral reflectance. We have tested two kinds of fern, Pteris vittata and Pteris mayii, beard grass and Indian mustard to phytoremediate soils contaminated with various forms of mercury (mercury chloride, mercury nitrate, and mercury sulfide). We have found that Chinese brake ferns (Pteris vittata) had a high capacity of uptake and translocation of Hg from contaminated soils. Since there is no known natural hyperaccumulator plant for Hg, Chinese brake fern (Pteris vittata) may be a good candidate for mercury phytoremediation.