Denitrification and phenol degradation in a contaminated aquifer

Spence, M.J., Bottrell, S.H., Higgo, J.J.W., Harrison, I. and Fallick, A.E. (2001) Denitrification and phenol degradation in a contaminated aquifer. Journal of Contaminant Hydrology, 53(3-4), pp. 305-318. (doi: 10.1016/S0169-7722(01)00171-1)

Abstract

A natural groundwater system modified by pollutant phenols and agricultural nitrate has been modelled in the laboratory by a series of sacrificial microcosm experiments. Samples of aquifer sediment and groundwater from the margin of the phenol plume were used to inoculate anaerobic microcosms enriched in nitrate and pollutant phenols. Rapid degradation of phenol and p-cresol was observed over a 35-day period leading to the generation of inorganic carbon and a number of transient intermediates. O- cresol proved to be recalcitrant on the experimental time- scale. A mass balance calculation shows that. during degradation, carbon was conserved in the aqueous phase. Groundwater-sediment interactions were monitored using carbon stable isotope data. A mass balance for solution TIC indicates that p-cresol degradation stimulated the dissolution of sedimentary carbonate phases due to the formation of carbonic acid. Coin pound-specific carbon isotope analysis (GC-IRMS) was used to search for C-13 enrichment in residual p-cresol. A slight enrichment trend (epsilon = - 2.5 parts per thousand) was tentatively identified. The potential of this fractionation effect for obtaining in situ degradation rates is discussed. Results from the microcosm experiments help to explain the observed distribution of nitrate and phenols within the polluted aquifer.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Fallick, Professor Anthony
• Authors: Spence, M.J., Bottrell, S.H., Higgo, J.J.W., Harrison, I., and Fallick, A.E.
• Subjects: T Technology > TD Environmental technology. Sanitary engineering; Q Science > QR Microbiology; Q Science > QE Geology
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Journal of Contaminant Hydrology
• ISSN: 0169-7722