Upscaled modeling of complex DNAPL dissolution

Area of Science:

• Environmental Engineering
• Geoscience
• Chemical Engineering

Background:

• Dense non-aqueous phase liquids (DNAPLs) pose significant environmental contamination challenges.
• Understanding DNAPL mass dissolution is crucial for effective remediation strategies.
• Existing models often require extensive input parameters and complex simulations.

Purpose of the Study:

• To develop a straightforward, upscaled model for DNAPL mass dissolution.
• To simplify the representation of complex dissolution processes.
• To provide a tool requiring minimal input data for DNAPL source zone characterization.

Main Methods:

• Developed an upscaled DNAPL mass dissolution model integrating advective and dispersive flow components.
• Incorporated changing relative permeability and a power law for mass depletion over time.
• Validated the model using numerical simulations, laboratory experiments, and a field study.

Main Results:

• The upscaled model successfully reproduced observed multistage mass discharge in all tested scenarios.
• Model predictions closely matched complete mass depletion in numerical and experimental studies.
• Key parameters like power law exponent remained relatively constant across different conditions.

Conclusions:

• The developed upscaled model offers a simplified yet effective approach to simulating DNAPL mass dissolution.
• Minimal input requirements make the model practical for real-world DNAPL source zone assessments.
• The model successfully captures the dynamics of DNAPL depletion influenced by changing relative permeability.