US EPA

1470636 

Technical Report 

AASERT-92 Research Training for Understanding the Fate of Environmental Pollutants 

Madsen, EL 

1996 

NTIS/02994632 

GRA and I 

GRA and I 

This award supported the training of two graduate students at Cornell University in their efforts to apply geochemical, physiological, and genetic approaches to understanding the fate of naphthalene in groundwater and sediments at a coal-tar contaminated field site. Three major scientific goals were accomplished. First, we extended methods and criteria for proving that environmental contaminants are actively being biodegraded in real time by using gas chromatography/mass spectrometry to detect a transient intermediate metabolite (1,2-dihydroxy- 1,2-dihydronaphthalene) in site waters. Second, we applied molecular procedures to extend understanding of genetic processes that affect environmental contaminants by extracting DNA from site sediments, using PCR to amplify the naphthalene catabolic gene, and contrasting restriction digests of the site-and pure culture-derived genes. Third, using a combination of field and laboratory procedures, we tested several hypotheses for explaining the persistence of naphthalene in the field site. We concluded that in situ oxygen limitation and reduced bioavailability were the causes. 

Sediments; *Environmental impact; *Ground water; *Water pollution; *Naphthalenes; Contaminants; Real time; Sites; Deoxyribonucleic acids; Oxygen; Laboratory procedures; Extraction; Geochemistry; Bioaccumulation; Sediments; Gas chromatography; Metabolites; Catabolism; Mass spectrometry