Date of Award
Doctor of Philosophy in Environmental Science - (Ph.D.)
Chemical Engineering, Chemistry and Environmental Science
Alexander E. Gates
Barbara B. Kebbekus
John R. Schuring
Lily Y. Young
Field data (including geology, hydrogeology, soil chemistry, groundwater chemistry, and aquifer characteristics) were analyzed at eight MGP sites located in the New Jersey Coastal Plain. These data were used to calculate biodegradation rate constants, which were then compared with laboratory microcosm data and published values. Isopleths were drawn from the field data to indicate the dominant biodegradation mechanisms at each of the sites, and stoichiometric calculations were used to determine the total capacity of the electron acceptors present to degrade the plume contaminants. In examining these data, the protocol described by the Air Force Center for Environmental Excellence (AFCEE) was used.
The results of this study showed that at most of the sites, first-order decay constants calculated from field data were generally greater than values reported for the same contaminants at fuel sites. Furthermore, the total capacity of electron acceptors at five of the sites could account for only about a third of the contaminant mass, although at the other three sites there appeared to be sufficient electron acceptors for complete plume attenuation. For most sites, at the plume periphery, aerobic degradation played a major role. However, within the plume, the dominant mechanisms were nitrate, iron, and sulphate reduction.
These findings were corroborated in the microcosm studies conducted for two of the sites, which indicated the importance of sulfate reduction in groundwater collected within the plume. The rate constant calculated for benzene from one of the microcosms was about the same order of magnitude as the constant calculated from field data. However, the rate constant calculated for naphthalene in the other microcosm from a different site was up to two orders of magnitude greater than the field data indicated.
Mortimer, Georgene, "An analysis of field data for evidence of anaerobic degradation of PAH and BTEX plumes at manufactured gas plant sites" (2002). Dissertations. 554.