Abstract
In Axelved, Denmark, an abandoned gas filling station serves
as a test field for phytoremediation. Laboratory studies accompany
the project. The toxicity of fresh and weathered gasoline
and diesel to willow and poplar trees was studied by use of a
tree transpiration toxicity test. The correlation between diesel
content in soil and decrease in willow tree transpiration (Salix
viminalis x schwerinii) was highly significant (r2 = 0.81, n =
19). The EC50 (50% inhibition of transpiration) for the sum of
hydrocarbons (HC) was determined to be 3910 mg/kg (95%
confidence interval from 2900 to 5270 mg/kg). The EC10 was
810 mg/kg (95% confidence interval 396 to 1660 mg/kg). The
results were verified with artificially mixed diesel and gasolinecontaminated
soils and two willow and one poplar species (S.
viminalis, S. alba and Populus nigra). The degradation of
radiolabeled m-xylene was studied with and without willows.
The compound was readily degraded. Willow trees accelerated
the elimination, but mainly due to the volatilization of m-xylene.
Model studies provided the result that biodegradation in soil is
the fastest elimination process at the site, but it is limited by the
availability of electron acceptors. The pollutants are almost
persistent in the groundwater, but in aerated soil, 10000 mg/kg
hydrocarbons at 1 m depth are degraded within 13 years. The
main effect of willows on the pollutants’ persistence is that
willows transpire water, lower the groundwater level and aerate
the soil, hereby speeding up biodegradation.
Original language | German |
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Journal | Umweltwissenschaften und Schadstoff-Forschung |
Volume | 13 |
Pages (from-to) | 227-236 |
ISSN | 0934-3504 |
DOIs | |
Publication status | Published - 2001 |
Keywords
- willows
- Degradation
- Populus
- Phytoremediation
- Petroleum
- gasoline
- xylene
- Diesel
- Salix
- Boden
- poplars