Experiments and sensitivity coefficients analysis for multiphase flow model calibration of enhanced DNAPL dissolution

Area of Science:

• Environmental Engineering
• Geoscience
• Chemical Engineering

Background:

• Subsurface contamination by nonaqueous phase liquids (NAPLs) necessitates effective remediation strategies.
• Multiphase flow modeling is crucial for optimizing NAPL remediation but faces calibration challenges due to data scarcity.
• Understanding NAPL behavior in heterogeneous porous media is key to successful site cleanup.

Purpose of the Study:

• To evaluate reagent-enhanced dense nonaqueous phase liquid (DNAPL) solubilization in laboratory settings.
• To investigate the sensitivity of multiphase flow model parameters for NAPL remediation.
• To improve multiphase flow model calibration using experimental data and sensitivity analysis.

Main Methods:

• Conducted laboratory experiments on reagent-enhanced DNAPL solubilization in saturated heterogeneous media.
• Utilized multiphase flow modeling to compute sensitivity coefficients for key parameters.
• Employed joint calibration of the multiphase flow model with experimental flushing data.

Main Results:

• Sensitivity analysis revealed key parameters influencing effluent concentrations in NAPL remediation.
• Model calibration highlighted the non-uniqueness challenge when initial NAPL distribution data is incomplete.
• The interphase mass transfer coefficient was found to be dependent on reagent solution viscosity and interfacial tension.

Conclusions:

• Experimental data and sensitivity analysis can aid in calibrating multiphase flow models for NAPL remediation.
• Reagent solution properties significantly impact the mass transfer coefficient during DNAPL remediation.
• Improved model calibration, considering experimental constraints, enhances the reliability of subsurface remediation predictions.