VOCs Fate and Partitioning in Vegetation: Use of Tree Cores in Groundwater Analysis
Analysis of tree cores collected from contaminated sites has shown that concentrations of VOCs in cores are related to groundwater concentrations. However, initial research was highly qualitative. To better understand the relationship of groundwater VOC concentrations to measured VOCs in tree cores, detailed understanding of contaminant behavior in vegetation is required. Work presented here investigates the interaction, with focus on the chlorinated solvents trichloroethylene, 1,1,2,2-tetrachloroethane, and carbon tetrachloride. The sorption and desorption partitioning of these compounds between air and woody biomass were investigated. Partitioning coefficients were determined for cores of trunks of large trees and smaller stem cuttings. The internal partitioning of these compounds between the transpiration stream and the woody biomass within the tree was also determined for cores. The partitioning coefficients of the compounds between air, water, and biomass of tree cores and trunks were related to the physicochemical characteristics of contaminants, mainly the Henry's law constant and vapor pressure. These partitioning coefficients relate the contaminants' concentra tion in the bulk solution and analyzed headspace of vials and therefore can be utilized to quantify the fate of contaminants in natural settings and in phytoremediation systems. Tissue analysis and determination of partitioning coefficients may provide an effective way to estimate the concentration of compounds in the transpiration stream and in the soil or groundwater in a noninvasive, extremely rapid, and cost-effective manner.
X. Ma and J. G. Burken, "VOCs Fate and Partitioning in Vegetation: Use of Tree Cores in Groundwater Analysis," Environmental Science and Technology, American Chemical Society (ACS), Jan 2002.
Civil, Architectural and Environmental Engineering
National Science Foundation (U.S.)
Keywords and Phrases
Groundwater Analysis; Tree Cores; VOCs; Vegetation
Article - Journal
© 2002 American Chemical Society (ACS), All rights reserved.