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| Titel |
Degradation of perchloroethene by combined application of microorganisms and
zero valent iron particles |
| VerfasserIn |
Philipp Schöftner, Dorothea Summer, Bernhard Wimmer, Thomas Reichenauer |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250139552
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| Publikation (Nr.) |
 EGU/EGU2017-2814.pdf |
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| Zusammenfassung |
| Chlorinated hydrocarbons (CHCs) are especially toxic pollutants which are frequently found
at contaminated sites in urban areas which are densely covered with buildings. In specific
in such areas, in-situ technologies are favourable since conventional remediation
technologies as excavation are often not applicable. This project examines a combination
of two in-situ remediation methods, in which the biotic degradation via bacteria
(dehalococcoides) is combined with abiotic degradation by zero-valent iron particles (ZVI).
ZVI particles are injected into the aquifer where CHC-molecules are reductively
dechlorinated. However Fe(0) is also oxidized by reaction with water leading to generation
of H2 without any CHC degradation. To achieve biotic degradation often strictly
anaerobic strains of the bacteria Dehalococcoides are used. These bacteria can
dechlorinate CHC by utilizing H2. By combining these processes the H2, produced
during the anaerobic corrosion of Fe(0), could be used by bacteria for further CHC
degradation.
Different Fe(0) particles (nano- and micro-scale) were combined with microbial
dehalogenation for dehalogenation of perchloroethene (PCE) in batch experiments. PCE
degradation rates and H2 production rates of the different particles and cultures were
determined. Additionally an artificial aquifer (approximately 1.0 x 0.5 x 0.5 metres) was
established. This aquifer was spiked with PCE and subsequently treated with Fe(0) particles
and microbial. Molasses was added to facilitate microbial dehalogenation.
Preliminary results showed that all H2 evolved during oxidation of Fe(0) were used by the
associated microbial community. Nevertheless the overall dehalogenation of chlorinated
compounds as well as the production of methane was hardly influenced by the addition of
Fe(0), at least not over the experimental period of 28 days. Independent if Fe(0) was added or
not all chlorinated compounds were dehalogenated whereby ethene and ethane were the only
end products. |
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