Investigation of stable carbon compound specific isotope analysis to monitor and quantify the biodegradation of chlorinated ethenes in groundwater systems
By: Penny Lea Morrill.
Published: 2004
Language: eng
Number of pages: 220
ISBN-13: 9780494220658
Subjects: Geochemistry.; Chlorohydrocarbons.; Groundwater -- Analysis.
Description: Identification and quantification of chlorinated ethene biodegradation were investigated using carbon compound specific isotope analysis (CSIA). A dynamic headspace sampling technique was developed and shown to be a robust, simple and effective method for isotopic analysis of dissolved chlorinated ethenes at low concentrations ([mu]g/L). This technique was used to monitor the biodegradation of tetrachloroethene (PCE) to ethene at a contaminated field site. At the field site, significant isotopic fractionation characteristic of biodegradation was observed in the isotope values of PCE and its degradation products trichloroethene (TCE), cis -1,2-dichloroethene (cDCE), and vinyl chloride (VC). During this study, stable carbon isotope analysis also provided one of the earliest lines of evidence for biodegradation. In laboratory and field experiments with an emplaced PCE dense nonaqueous phase liquid (DNAPL) source, isotopic fractionation was observed in the isotope values of the dechlorination intermediates produced by biodegradation, but not in the aqueous PCE near the DNAPL. These results confirm the hypothesis that isotopic fractionation due to biodegradation will not be observed in aqueous PCE close to the source zone. A model was developed to predict concentration values from isotope data for each step in the sequential reaction of PCE to non-toxic ethene. ...
Notes: Thesis (Ph.D.) -- University of Toronto, 2004.

Includes bibliographical references.

Electronic version licesed for access by U. of T. users.