| Abstract: | Heavy metal contamination of soil resulting from anthropogenic sources poses a significant challenge in many industrialized societies. The current technologies employed for removal of heavy metals often involve expensive ex-situ processes requiring sophisticated equipment and removal, transportation, and purification of the soil. Generally, in-situ remedial technologies are favored to ex-situ methods for detoxification, neutralization, degradation, or immobilization of contaminants. In-situ bioremediation is increasingly favored because of its effectiveness and low cost. A new type of bioremediation, known as vegetative remediation or “phytoremediation,” uses metal-tolerant hyperaccumulator plants to take up metal ions from soils and store them in their aboveground parts. To select the appropriate phytoremediation technology, one must understand the technical feasibility, cost effectiveness, and availability of the suitable plant species. Equally important is determining whether the site's soil conditions are optimal to enhance or restore the soil biological activity. Before phytoremediation can be exploited on a contaminated site, greenhouse-scale confirmatory testing is necessary to measure plant uptake and correlate shoot metal concentrations to available soil metals. These tests also validate that the harvesting and subsequent disposal of metal-containing plant tissues are environmentally safe and manageable. |
