Study of Scale and Time Dependent Parameters for Reactive Solute Transport through Stratified Porous Media

Monday, December 3, 2018: 11:00 a.m.
N109 (Las Vegas Convention Center)
Abhimanyu Sharma , School of Engineering, Indian Institute of Technology Mandi, Mandi, India
Deepak Swami , School of Engineering, Indian Institute of Technology Mandi, Mandi, India
Abhay Guleria , School of Engineering, Indian Institute of Technology Mandi, Mandi, India

In this study, better simulation of observed experimental data for reactive solute transport through stratified porous media is intended. Effectiveness of distance and time dependent dispersion (TDD) to simulate fate of sorbing solute is compared to fulfill this objective. A physical and chemical-non-equilibrium (MPNE) model is used to capture this phenomenon to account for heterogeneity and site specific sorption in subsurface soil medium. Nonlinear least square optimization algorithm is used to estimate transport parameters. For a better resolution during breakthrough and tailing portion, semi-log plots are used to characterize the time scale simulation. Experiment data of reactive solute (fluoride) transport reported in Swami et al. (2016) is used for comparative analysis. It is observed that MPNE with TDD simulate experimental results with higher accuracy compared to distance dependent dispersion, especially in breakthrough and tailing portions. Parameters estimation algorithm resulted lesser values of effective dispersion and first order diffusive mass transfer for TDD. While higher values of effective dispersion and mass transfer coefficient for distance dependent dispersion identifies an overestimation in solute spreading for identical transport processes. To have a better idea of distance and time dependent dispersion in terms of mass recovery, temporal moment is calculated. Zeroth temporal moment obtained in the case of time dependent dispersion is less, which suggests that effective dispersion is less for TDD. Peclet and Damkohler number are computed to identify the dominance of dispersion and mass transfer over advection since porous medium is affected by physical heterogeneity. It is concluded that TDD gives a better description of contaminant transport through heterogeneous porous media, since it takes in to consideration the temporal variability of dispersion and diffusive mass transfer during the complete evolution of solute.
Abhimanyu Sharma, School of Engineering, Indian Institute of Technology Mandi, Mandi, India
I am Abhimanyu Sharma, working as research scholar (PhD) at Indian Institute of Technology Mandi. Currently I am working on modelling of solute transport through porous media. I have three years of research experience.



Deepak Swami, School of Engineering, Indian Institute of Technology Mandi, Mandi, India
Dr. Deepak Swami is an Assistant Professor in School of Engineering IIT Mandi. His area of research includes groundwater and surface water modelling. He has more than 8 years of research experience. He has publication in many reputed journals.


Abhay Guleria, School of Engineering, Indian Institute of Technology Mandi, Mandi, India
Abhay Guleria is a Master of Science (by Research) student in School of Engineering, IIT Mandi, India. He has three years of research experience. My research interests are Solute transport modelling through saturated porous media, parameter estimation.