Predictive Relationships for Uptake of Organic Contaminants by Hybrid Poplar Trees

Twelve organic compounds commonly found at hazardous waste sites were studied for uptake by hybrid poplar trees. The vegetative uptake of many of these compounds has not previously been demonstrated for plant species being utilized for phytoremediation, such as hybrid poplar trees. Experiments were conducted hydroponically utilizing 14C-labeled compounds to ascertain translocation and fate. Predictive relationships for the translocation and partitioning to plant tissues were developed from the experimental data. Translocation and partitioning relationships based on compounds' octanol−water partitioning coefficients (log Kow) produced the best results, but the relationships did not allow for fully accurate prediction of each contaminant's fate. Translocation and subsequent transpiration of volatile organic compounds (VOCs) from the leaves to the atmosphere was shown to be a significant pathway. As full-scale phytoremediation systems are deliberated, the pathways investigated here should be considered in terms of a contaminant removal mechanism and potential contamination of the vegetation.