Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.jhazmat.2020.124741
Licence creative commons licence
Title (Primary) Towards predicting DNAPL source zone formation to improve plume assessment: Using robust laboratory and numerical experiments to evaluate the relevance of retention curve characteristics
Author Engelmann, C.; Lari, K.S.; Schmidt, L.; Werth, C.J.; Walther, M.
Source Titel Journal of Hazardous Materials
Year 2021
Department ENVINF; MET
Volume 407
Page From art. 124741
Language englisch
Topic T5 Future Landscapes
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Keywords DNAPL; Source zone geometry; Laboratory release experiment; Reflective optical imaging; Numerical multiphase flow modeling
Abstract We conducted multiple laboratory trials in a robust and repeatable experimental layout to study dense non-aqueous phase liquid (DNAPL) source zone formation. We extended an image processing and analysis framework to derive DNAPL saturation distributions from reflective optical imaging data, with volume balance deviations < 5.07%. We used a multiphase flow model to simulate source zone formation in a Monte Carlo approach, where the parameter space was defined by the variation of retention curve parameters. Integral and geometric measures were used to characterize the source zones and implemented into a multi-criteria objective function. The latter showed good agreement between observation data and simulation results for effective DNAPL saturation values > 0.04, especially for early stages of DNAPL migration. The common hypothesis that parameters defining the DNAPL-water retention curves are constant over time was not confirmed. Once DNAPL pooling started, the optimal fit in the parameter space was significantly different compared to the earlier DNAPL migration stages. We suspect more complex processes (e.g., capillary hysteresis, adsorption) to become relevant during pool formation. Our results reveal deficits in the grayscale-DNAPL saturation relationship definition and laboratory estimation of DNAPL-water retention curve parameters to overcome current limitations to describe DNAPL source zone formation.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=24017
Engelmann, C., Lari, K.S., Schmidt, L., Werth, C.J., Walther, M. (2021):
Towards predicting DNAPL source zone formation to improve plume assessment: Using robust laboratory and numerical experiments to evaluate the relevance of retention curve characteristics
J. Hazard. Mater. 407 , art. 124741 10.1016/j.jhazmat.2020.124741