Uptake of trichloroethylene by hybrid poplar trees grown hydroponically in flow-through plant growth chambers

Autor: Bruce Bugbee, Julie K. Chard, Brady J. Orchard, William J. Doucette
Rok vydání: 2000
Předmět:
Zdroj: Environmental Toxicology and Chemistry. 19:895-903
ISSN: 1552-8618
0730-7268
DOI: 10.1002/etc.5620190416
Popis: Phytoremediation is being promoted as a cost-effective treatment option for shallow groundwater and soils contaminated with trichloroethylene (TCE). However, its effectiveness is difficult to assess due to contradictory reports regarding the magnitude of plant uptake and phytovolatilization. Experimental artifacts and plant stress, resulting from the use of static or low-flow plant growth laboratory systems, may account for part of the discrepancy. High exposure concentrations and short durations may also cause artifacts in laboratory studies. A dual-chamber plant growth system designed to minimize experimental artifacts was used to determine the uptake of ( 14C) TCE by hydroponically grown hybrid poplar as a function of plant stress (aerobic and oxygen-reduced root zone), exposure concentration (1-70 mg/L), and exposure duration (12 or 26 d). The (14C)TCE recoveries ranged from 92 to 101% in 11 dosed chambers. Trichloroethylene mass equivalent concentrations in the shoot tissue (2-168 mg/kg) were dependent on the amount of water transpired and the exposure concentration. Root-zone oxygen status did not significantly impact TCE uptake. Transpiration stream concentration factors (TSCFs) determined in these studies (0.02-0.22) were independent of exposure duration and are much lower than those previously reported and predicted. The role of TSCF and other factors in estimating the significance of plant uptake in the phytoremediation of TCE-contaminated groundwater is discussed.
Databáze: OpenAIRE
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