Journal article
Biodegradation of NSO-compounds under different redox-conditions
Laboratory experiments were carried out to investigate the potential of groundwater microorganisms to degrade selected heterocyclic aromatic compounds containing nitrogen, sulphur, or oxygen (NSO-compounds) under four redox-conditions over a period of 846 days. Eight compounds (pyrrole, 1-methylpyrrole, quinoline, indole, carbazole, dibenzothiophene, benzofuran, and dibenzofuran) were degraded under aerobic conditions, whereas thiophene and benzothiophene were degraded only when other compounds were degraded concomitantly.
Quinoline and indole were the only two NSO-compounds degraded under anaerobic conditions, even though the microorganisms present in the anaerobic microcosms were active throughout the incubation period. A high variability in the lag period among the NSO-compounds was observed under aerobic conditions.
While quinoline, indole, and carbazole were degraded with a lag period of 3-25 days, the lag periods for pyrrole, dibenzothiophene, benzofuran, and dibenzofuran were significantly longer (29-278 days). Under anaerobic conditions, lag periods of 100-300 days were observed. Differences in the degradation rate among the compounds were also observed.
Indole, quinoline, carbazole, and benzofuran were quickly degraded in the aerobic microcosms, whereas a slow degradation of dibenzothiophene and dibenzofuran was observed. Pyrrole and 1-methylpyrrole were slowly degraded and 1-methylpyrrole was not completely removed within the 846 days. The anaerobic degradation rate was significantly slower than the aerobic degradation rate.
The degradation rate under sulphate-reducing conditions was higher than under denitrifying and methanogenic conditions, though after re-addition of a compound a quick removal was observed. The persistence of many NSO-compounds under anaerobic conditions together with the long lag periods and the low degradation rates under aerobic conditions suggest that NSO-compounds might persist in groundwater at creosote-contaminated sites. (C) 1997 Elsevier Science B.V.
Language: | English |
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Year: | 1997 |
Pages: | 177-197 |
ISSN: | 18736009 and 01697722 |
Types: | Journal article |
DOI: | 10.1016/S0169-7722(96)00042-3 |
ORCIDs: | Arvin, E. |