Experimentally based pore network modeling of NAPL dissolution process in heterogeneous porous media

• Published in: Journal of contaminant hydrology Vol. 228; p. 103565
• Main Authors: Khasi, Saeid, Ramezanzadeh, Mehdi, Ghazanfari, Mohammad H.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2020
• Subjects: Heterogeneous porous media; Interphase mass transfer; Micromodel experiment; NAPL; Pore network modeling; Heterogeneous porous media; Micromodel experiment; Pore network modeling; NAPL; Interphase mass transfer
• ISSN: 0169-7722; 1873-6009
• DOI: 10.1016/j.jconhyd.2019.103565

Practical designs of non-aqueous phase liquids (NAPLs) remediation strategies require reliable modeling of interphase mass transfer to predict the retraction of NAPL during processes such as dissolution. In this work, the dissolution process of NAPL during two-phase flow in heterogeneous porous media is studied using pore-network modeling and micromodel experiments. A new physical-experimental approach is proposed to enhance the prediction of the dissolution process during modeling of interphase mass transfer. In this regard, the normalized average resident solute concentration is evaluated for describing the dissolution process at pore-level. To incorporate the effect of medium heterogeneities, a new experimental factor is considered for enhancing corner diffusion modeling. In addition, capillary desaturation curves (CDCs) are predicted during hydraulic flow modeling to estimate initial residual NAPL saturation. The developed network model can predict residual NAPL saturations and mass transfer rate coefficient for a NAPL-water system at different injection rates and fluid saturations. The evaluated mass transfer rate coefficients using the proposed physical-experimental approach show a significant improvement compared to either mechanistic or empirical methods. The proposed approach in this study can be attractive for possible applications in commercial simulators of contaminant transport in porous media. •A pore network model is developed for flow, transport, and dissolution of NAPL.•The network structure and flow model are determined based on micromodel experiments.•A physical-experimental approach is proposed for modeling of the dissolution process.•A new experimental factor is introduced for improving corner diffusion modeling.•The predicted mass transfer rate coefficients match the micromodel experimental data.