Assessment of Chemical and Microbiological Signatures
during Natural Attenuation of Gasoline-Contaminated Groundwater |
|
Yoh TAKAHATA *1, Toshihiro HOAKI *1, Yuki KASAI *2
and Kazuya WATANABE *2 |
A gasoline-contaminated groundwater in Kumamoto
city had been treated by the pumping and aeration for more than 10 years, and
the treatment method has been changed to monitored natural attenuation. Depletion
of DO, nitrate and sulfate, and the increases of iron and manganese concentrations
have been occured in contaminated groundwater. Between the contaminated and
non-contaminated zones, there was a boundary zone, where BTX were not detected
but total cell counts were high. Laboratory incubation of groundwater supplemented
with BTX showed that BTX disappeared rapidly in the groundwater obtained from
the boundary zones, while the BTX-degradation capacity in groundwater obtained
from the center of the contaminated zone was marginal. Supplementation of contaminated
groundwater with oxygen, nitrate, or sulfate stimulated BTX biodegradation.
Dominant species on DGGE profiles after incubation of groundwater were possibly
important for evaluating natural attenuation of BTX in the groundwater. |
keywords: |
BTX, natural attenuation,
monitored natural attenuation, anaerobic bacteria, PCR-DGGE |