Towards predicting DNAPL source zone formation to improve plume assessment: Using robust laboratory and numerical experiments to evaluate the relevance of retention curve characteristics

JOURNAL OF HAZARDOUS MATERIALS

卷:407

Article

Engelmann, Christian^1,2,3  Lari, Kaveh Sookhak^3,4  Schmidt, Luisa^1,5,6  Werth, Charles J.⁷  Walther, Marc^1,2 

[1] Tech Univ Dresden, Inst Groundwater Management, Fac Environm Sci, Bergstr 66, D-01069 Dresden, Germany

[2] UFZ Helmholtz Ctr Environm Res, Dept Environm Informat, Permoserstr 15, D-04318 Leipzig, Germany

[3] CSIRO Land & Water, Private Bag 5, Wembley, WA 6913, Australia

[4] Edith Cowan Univ, Sch Engn, 270 Joondalup Dr, Joondalup, WA 6027, Australia

[5] Tech Univ Dresden, Fac Environm Sci Inst Photogrammetry & Remote Sen, Helmholtzstr 10, D-01069 Dresden, Germany

[6] UFZ Helmholtz Ctr Environm Res, Dept Monitoring & Explorat Technol, Permoserstr 15, D-04318 Leipzig, Germany

[7] Univ Texas Austin, Bettie Margaret Smith Chair Environm Hlth Engn, Dept Civil Architectural & Environm Engn, Austin, TX 78712 USA

关键词: DNAPL;    Source zone geometry;    Laboratory release experiment;    Reflective optical imaging;    Numerical multiphase flow modeling;   

DOI  :  10.1016/j.jhazmat.2020.124741

来源: Elsevier

【 摘 要 】

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.

【 授权许可】

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