NSF Award
9901716
This Small Business Innovation Research Phase II project describes the development of a new method for in situ removal of contaminants from soil by combining the processes of phytoremediation and electrokinetic remediation of soil. Phytoremediation is an attractive approach for cleanup of soil because it is a low cost and low maintenance technology, which can be applied in treatment of soils contaminated by heavy metals, radionuclides and organic contaminants. However, its application is limited to surface contamination only because the cleanup depth is strictly determined by the length of the plant roots. It is also a passive technology in terms of contaminant transport. The movement of contaminants in the soil is induced exclusively by a slow plant root suction, thus the efficiency of the contaminant removal depends on the extension of the plant roots in the soil subsurface. The new combined electrokinetic phytoremediation technology developed in Phase I utilizes the electrokinetic effects induced in soil by the application of an electric field to achieve an efficient transport of contaminants in the rhizosphere and to enhance metal accumulation in the plant roots. The Phase I results demonstrated that using the electrokinetic phytoremediation process up to two orders of magnitude higher lead concentration could be achieved in Brassica juncea mustard plants compared to the conventional phytoremediation process. Phase II will focus on the optimization and scaling-up of the process parameters governing the enhancement of contaminant extraction by the plants in conditions of the applied electric field. The field test results will yield technical and economical evaluation of the process and recommendations about applicability of the combined electrokinetic phytoremediation to contaminated sites with varying chemical and hydrogeological characteristics.<br/> The developed electrokinetic phytoremediation process will have large applications for in situ cleanup of<br/>soils contaminated by heavy metals, radionuclides, and/or organic contaminants. Compared to conventional phytoremediation processes, the proposed process can be applied to soils where contaminants are located deeper than the root zone of plant hyperaccumulators. This will significantly extend the application of phytoremediation to the sites with deep contaminant plumes.
