NEW MARKERS FOR MONITORING THE BIODEGRADATION OF PETROLEUM FUELS IN SOIL

摘要

We have investigated the use of per-deuterated and phenyl-labelled alkanes as indicators of the biological degradation of petroleum fuels. In laboratory scale reactors containing soil, peat moss and the target compounds, both compounds were completely degraded at a similar rate to diesel fuel within 16 days at room temperature. Degradation slowed markedly in a nitrogen purged reactor and was virtually stopped by incubation at 4℃ and by the biocide Kathon~(～R). Corresponding with the disappearance of the starting materials from the reactors was the appearance of fatty acids possessing the labels present in the original compounds. ~2H-Tetradecanoic-d_(27) acid arising from ~2H-tetradecane-d_(30) and 12-Phenyldodecanoic acid formed from phenyldodecane were identified. The fatty acid metabolites were found to be incorporated into complex polar lipids and were not found as free acids. The results of this study demonstrate that ~2H-tetradecane and phenyldodecane in soil are both biologically degraded, converted into the corresponding fatty acids and incorporated into higher lipids. The labels in both target molecules survived the metabolic process allowing the metabolites to be traced directly to the parent molecules. The findings show that these labelled compounds can be used as sensitive monitors for the biodegradation of petroleum fuels.