Determination of DNAPL Mass Flux Reduction as a Function of Source Zone Mass Removal
EMSL Project ID
15491
Abstract
The fate of organic chemicals in groundwater and the risks they pose to the environment are topics of numerous environmental studies. Among the most common groundwater contaminants are non-aqueous phase liquids (NAPL), such as tetrachloroethene (PCE), trichloroethene (TCE), dichloroethene (DCE), vinyl chloride and carbon tetrachloride. The harmful effects of these chemicals have created a demand for the development of environmental remediation technologies. One remediation approach is the removal of contaminant mass from the source zone. In order for source zone mass removal to be effective, the dissolution dynamics of the contaminant needs to be characterized. Using the intermediate scale flow cells available at Pacific Northwest National Laboratory (PNNL), the geometry of the source zone can be varied as well as the composition of the porous media in and surrounding the source zone. . The facility at PNNL provides the ability to directly measure the insitu NAPL saturation of the source zone, and consequently the degree of dissolution, through the use of dual-energy gamma radiation measurements. These measurements will provide another level of understanding to the source zone dissolution process. In addition to looking at the dissolution of the source zone, the mass flux of contaminant leaving the source zone will also be examined. Presently, it is unclear how much contaminant mass must be removed from the source zone in order to allow MNA to be a feasible remediation technique. The change in mass flux as a function of contaminant mass removed can be determined during the same dissolution experiments mentioned above. The dual-energy gamma radiation measurements will provide a measurement of the insitu NAPL saturation of the source zone. Monitoring the NAPL saturation through time will provide a measure of the amount of mass removed from the source zone. Hence, through these same dissolution experiments, a function relating the change in mass flux versus mass removed can be established. The facilities available at PNNL provide the opportunity to examine dissolution and its effect on the mass flux leaving the source zone. Through these experiments a better understanding of the potential of source zone mass removal can be acquired.
Project Details
Project type
Exploratory Research
Start Date
2005-06-27
End Date
2007-03-22
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Brusseau, M.L., E.L. DiFilippo, J.C. Marble and M. Oostrom. 2008. Mass-removal and mass-flux-reduction behavior for sources zones with hydraulically-poorly accessible immiscible liquid. Chemosphere 71, no. 8: 1511-1521.
DiFilippo, E. L., J.C. Marble, M. Oostrom, and M.L. Brusseau. 2006. Investigation of Mass Flux Reduction as a Function of Source Zone Mass Removal for Immiscible Liquid Contaminated Aquifers. National Institute of Environmental Health Sciences (NIEHS) Superfund Basic Research Program (SBRP) Annual Meeting. December 2006.
DiFilippo, Erica, L., Mark L. Brusseau, Mart Oostrom, and Tom W. Wietsma. 2005. Experimental Investigation of DNAPL Mass Flux Reduction as a Function of Source Zone Mass Removal. American Geophysical Annual Meeting - December 2005.
M.L. Brusseau, E. DiFilippo, J.C. Marble, and M. Oostrom. MASS-REMOVAL AND MASS-FLUX-REDUCTION BEHAVIOR FOR SOURCE ZONES WITH HYDRAULICALLY POORLY-ACCESSIBLE IMMISCIBLE LIQUID. submitted to Chemosphere