Modeling 3D-CSIA data
| Autor: | Mindy Vanderford, Héloïse A.A. Thouement, Tomasz Kuder, Paul Philp, Boris M. van Breukelen, Philip E. Stack |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Halogenation
0208 environmental biotechnology chemistry.chemical_element 02 engineering and technology 010501 environmental sciences 01 natural sciences Vinyl chloride chemistry.chemical_compound Chlorinated ethenes Isotopes Computational chemistry Kinetic isotope effect Chlorine Reductive dechlorination Environmental Chemistry Isotopologue Groundwater 0105 earth and related environmental sciences Water Science and Technology Stable isotopes Dehalococcoides biology Stable isotope ratio Chloroflexi Ethylenes Models Theoretical Reactive transport modeling biology.organism_classification Carbon Trichloroethylene 020801 environmental engineering Kinetics Contaminated sites Biodegradation Environmental chemistry 13. Climate action Intramolecular force Environmental chemistry Natural attenuation Water Pollutants Chemical Environmental Monitoring Hydrogen |
| Zdroj: | Journal of Contaminant Hydrology, 204 |
| ISSN: | 0169-7722 |
| DOI: | 10.1016/j.jconhyd.2017.07.003 |
| Popis: | Reactive transport modeling of multi-element, compound-specific isotope analysis (CSIA) data has great potential to quantify sequential microbial reductive dechlorination (SRD) and alternative pathways such as oxidation, in support of remediation of chlorinated solvents in groundwater. As a key step towards this goal, a model was developed that simulates simultaneous carbon, chlorine, and hydrogen isotope fractionation during SRD of trichloroethene, via cis-1,2-dichloroethene (and trans-DCE as minor pathway), and vinyl chloride to ethene, following Monod kinetics. A simple correction term for individual isotope/isotopologue rates avoided multi-element isotopologue modeling. The model was successfully validated with data from a mixed culture Dehalococcoides microcosm. Simulation of Cl-CSIA required incorporation of secondary kinetic isotope effects (SKIEs). Assuming a limited degree of intramolecular heterogeneity of δ37Cl in TCE decreased the magnitudes of SKIEs required at the non-reacting Cl positions, without compromising the goodness of model fit, whereas a good fit of a model involving intramolecular CCl bond competition required an unlikely degree of intramolecular heterogeneity. Simulation of H-CSIA required SKIEs in H atoms originally present in the reacting compounds, especially for TCE, together with imprints of strongly depleted δ2H during protonation in the products. Scenario modeling illustrates the potential of H-CSIA for source apportionment. |
| Databáze: | OpenAIRE |
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