Journal article
Test of aerobic TCE degradation by willows (Salix viminalis) and willows inoculated with TCE-cometabolizing strains of Burkholderia cepacia
Trichloroethylene (TCE) is a widespread soil and groundwater pollutant and clean-up is often problematic and expensive. Phytoremediation may be a cost-effective solution at some sites. This study investigates TCE degradation by willows (S. viminalis) and willows inoculated with three strains of B. cepacia (301C, PR1-31 and VM1330-pTOM), using chloride formation as an indicator of dehalogenation.
Willows were grown in non-sterile, hydroponic conditions for 3 weeks in chloride-free nutrient solution spiked with TCE. TCE was added weekly due to rapid loss by volatilization. Chloride and TCE in solution were measured every 2-3 days and chloride and metabolite concentrations in plants were measured at test termination.
Based on transpiration, no tree toxicity of TCE exposure was observed. However, trees grown in chloride-free solution showed severely inhibited transpiration. No or very little chloride was formed during the test, and levels of chloride in TCE-exposed trees were not elevated. Chloride concentrations in chloride containing TCE-free nutrient solution doubled within 23 days, indicating active exclusion of chloride by root cell membranes.
Only traces of TCE-metabolites were detected in plant tissue. We conclude that TCE is not, or to a limited extent (less than 3%), aerobically degraded by the willow trees. The three strains of B. cepacia did not enhance TCE mineralization. Future successful application of rhizo- and phytodegradation of TCE requires measures to be taken to improve the degradation rates.
Language: | English |
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Publisher: | Springer Berlin Heidelberg |
Year: | 2017 |
Pages: | 18320-18331 |
ISSN: | 16147499 and 09441344 |
Types: | Journal article |
DOI: | 10.1007/s11356-017-9420-8 |
ORCIDs: | Clausen, Lauge Peter Westergaard , Broholm, Mette Martina and Trapp, Stefan |
B. cepacia Chloride Dehalogenation Phytoremediation TCE degradation Trichloroethylene Willow tree toxicity test
ACCUMULATION Atmospheric Protection/Air Quality Control/Air Pollution Biodegradation, Environmental Burkholderia cepacia CYANIDE Ecotoxicology Environment Environment, general Environmental Chemistry Environmental Health Hydroponics METABOLISM PHYTOREMEDIATION PHYTOTOXICITY REMEDIATION SC7 Salix Soil Pollutants TREES TRICHLOROACETIC-ACID TRICHLOROETHYLENE DEGRADATION Trees WOODY-PLANTS Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution