A5068880722- Methane Hydrates and Related Phenomena
- Hydrocarbon exploration and reservoir analysis
- Atmospheric and Environmental Gas Dynamics
- Microbial bioremediation and biosurfactants
- Groundwater and Isotope Geochemistry
- Groundwater flow and contamination studies
- Toxic Organic Pollutants Impact
- Environmental remediation with nanomaterials
- Isotope Analysis in Ecology
- Chemical Reactions and Isotopes
- Radioactive element chemistry and processing
- Microbial Community Ecology and Physiology
- Planetary Science and Exploration
- Atmospheric Ozone and Climate
- Geology and Paleoclimatology Research
- Geological and Geochemical Analysis
- Water Treatment and Disinfection
- Spectroscopy and Laser Applications
- Radioactive contamination and transfer
- CO2 Sequestration and Geologic Interactions
- Synthesis and characterization of novel inorganic/organometallic compounds
- Nuclear Physics and Applications
- Geological Studies and Exploration
- Mass Spectrometry Techniques and Applications
- Chemical Reaction Mechanisms
University of Toronto
2011-2022
Toronto Public Health
2020
NASA Astrobiology Institute
2011
Indiana University Bloomington
2011
Institute of Groundwater Ecology
2006-2009
Helmholtz Zentrum München
2009
Center for Environmental Health
2009
North Carolina State University
2009
Cornell University
2005
University of California, Davis
2002
ABSTRACT Compound-specific isotope analysis has the potential to distinguish physical from biological attenuation processes in subsurface. In this study, carbon and hydrogen isotopic fractionation effects during biodegradation of benzene under anaerobic conditions with different terminal-electron-accepting are reported for first time. Different enrichment factors (ε) (range −1.9 −3.6‰) −29 −79‰) were observed nitrate-reducing, sulfate-reducing, methanogenic conditions. These differences not...
Determination of compound-specific carbon isotope values by continuous flow ratio mass spectrometry is impacted variation in several routine operating parameters which one the most important signal size, or linearity. Experiments were carried out to evaluate implications these on both reproducibility and accuracy δ13C measurements. A new method described for assessing total instrumental uncertainty analysis, incorporating reproducibility. These findings have application analysis...
Dissolved H2 concentrations up to the mM range and levels 9–58% by volume in free gas phase are reported for groundwaters at sites Precambrian shields of Canada Finland. Along with previously dissolved 7.4 from Witwatersrand Basin, South Africa, these findings indicate that deep Shield fracture waters contain some highest ever represent a potentially important energy-rich environment subsurface microbial life. The δ2H isotope signatures Canada, Finland, Africa consistent H2-producing...
Methyl group oxidation, SN2-type hydrolysis, and SN1-type hydrolysis are suggested as natural transformation mechanisms of MTBE. This study reports for the first time MTBE isotopic fractionation during acid oxidation by permanganate. In enrichment factors were εC = −4.9‰ ± 0.6‰ carbon εH −55‰ 7‰ hydrogen. Position-specific values εC,reactive position −24.3‰ 2.3‰ εH,reactive −73‰ 9‰, giving kinetic isotope effects KIEC 1.025 0.003 KIEH 1.08 0.01 consistent with an involving tert-butyl group....
Carbon isotope fractionation is of great interest in assessing chlorinated ethene transformation by nanoscale zero-valent iron at contaminated sites, particularly distinguishing the effectiveness an implemented abiotic degradation remediation scheme from intrinsic biotic degradation. Transformation trichloroethylene (TCE), cis-dichloroethylene (cis-DCE), and vinyl chloride (VC) with two types materials showed different reactivity trends, but relatively consistent carbon enrichment factors...
Abstract The discovery of hydrogen-rich waters preserved below the Earth’s surface in Precambrian rocks worldwide expands our understanding habitability terrestrial subsurface. Many deep microbial ecosystems these survive by coupling hydrogen oxidation to sulfate reduction. Hydrogen originates from water–rock reactions including serpentinization and radiolytic decomposition water induced decay radioactive elements host rocks. origin dissolved sulfate, however, remains unknown. Here we...
Carbon and hydrogen isotopic fractionation during aerobic biodegradation of MTBE by a bacterial pure culture (PM1) mixed consortia from Vandenberg Air Force Base (VAFB) were studied in order to assess the relative merits stable carbon versus analysis as an indicator biodegradation. enrichment residual up 8.1‰ was observed at 99.7% reproducible PM1 VAFB experiments, yielding similar factors (ε) −2.0‰ ± 0.1‰ −2.4‰ 0.3‰ for replicates experiment −1.5‰ −1.8‰ experiment. Hydrogen highly cultures,...
Polaromonas sp. strain JS666 is the only bacterial isolate capable of using cis-dichloroethene (cDCE) as a sole carbon and energy source. Studies cDCE degradation in this novel organism are interest because potential bioremediation biocatalysis applications. The primary cellular responses to growth on were explored proteomics transcriptomics identify genes upregulated by cDCE. Two-dimensional gel electrophoresis revealed upregulation annotated encoding glutathione S-transferase,...
Compound-specific carbon and hydrogen isotope analysis was used to investigate biodegradation of benzene ethylbenzene in contaminated groundwater at Dow Benelux BV industrial site. δ13C values for dissolved downgradient samples were enriched by up 2 ± 0.5‰ 13C, compared the value source area samples. δ2H exhibited larger isotopic enrichments 27 5‰ 50 relative area. The observed fractionation provides evidence both within study BV. estimated extents derived from compositions each sample are...
1,2-Dichloroethane (1,2-DCA) is a widespread groundwater contaminant known to be biodegradable under aerobic conditions via enzymatic oxidation or hydrolytic dehalogenation reactions. Current literature reports that stable carbon isotope fractionation of 1,2-DCA during biodegradation large and reproducible (−27 −33‰). In this study, significant variation in the magnitude was observed. Biodegradation experiments involving microcosms, enrichment cultures, pure microbial cultures produced...