Iron-mediated microbial oxidation and abiotic reduction of organic contaminants under anoxic conditions

Autor(en)

Nicole B. Tobler, Thomas B. Hofstetter, Kristina Lotte Straub, Daniela Fontana, René P. Schwarzenbach

Abstrakt

In anoxic environments, the oxidation of organic compounds, such as BTEX fuel components, by dissimilatory Fe(III) reduction can generate reactive mineral-bound Fe(II) species, which in turn are able to reduce other classes of organic and inorganic groundwater contaminants. In this study, we designed and evaluated an anaerobic batch reactor that mimicks iron-reducing conditions to investigate the factors that favor the coupling of microbial toluene oxidation and abiotic reduction of nitroaromatic contaminants. We investigated the influence of different Fe(III)-bearing minerals and combinations thereof on the coupling of these two processes. Results from laboratory model systems show that complete oxidation of toluene to CO2 by Geobacter metallireducens in the presence of Fe(III)-bearing minerals leads to the formation of mineral-bound Fe(II) species capable of the reduction of 4-nitroacetophenone. Whereas significant microbial toluene oxidation was only observed in the presence of amorphous Fe(III) phases, reduction of nitroaromatic compounds only proceeded with Fe(II) species bound to crystalline Fe(III) oxides. Our results suggest that in anoxic soils and sediments containing amorphous and crystalline iron phases simultaneously, coupling of microbial oxidation and abiotic reduction of organic compounds may allow for concurrent natural attenuation of different contaminant classes

Organisation(en)

Externe Organisation(en)

Eidgenössische Technische Hochschule Zürich

Journal

Environmental Science & Technology

Band

41

Seiten

7765-7772

Anzahl der Seiten

8

ISSN

0013-936X

Publikationsdatum

2007

Peer-reviewed

Ja

ÖFOS 2012

105105 Geochemie, 105904 Umweltforschung

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/f76abcb6-5eb3-4dc0-a3c6-f2fc02f18d64