Chlorinated solvents phytoremediation: Uptake and diffusion

Trichloroethylene and 1,1,2,2 -tetrachloroethane were taken up by hybrid poplar trees and released to the atmosphere. Volatilization to the atmosphere took place directly from the transpiration pathway and occurs through diffusion from the conductive xylem tissues. Laboratory-scale measurements show the flux of the volatile compounds was a function of vertical distance up the stem, evapotranspiration rates, and the concentration of VOCs in the feed solution. Full-scale measurements corroborate this theory as concentrations and fluxes of chlorinated VOCs were measured directly from the trunks of trees at field-scale phytoremediation systems treating contaminated groundwater. This research provides the first definitive measurements of diffusion directly from the xylem tissues in live plants and of VOCs released to the atmosphere in a field-scale phytoremediation application. In addition, mass removal and volatilization rates for full-scale phytoremediation projects can be calculated using methods outlined in this work and evapotranspiration rates for the plot.

Proceedings of the Third International Conference on Remediation of Chlorinated and Recalcitrant Compounds

Chlorinated solvents phytoremediation: Uptake and diffusion Conference Paper