Numerical analysis of breakthrough curves and temporal moments for solute transport in triple-permeability porous medium

This paper presents the triple advective–dispersive transport equations considering equilibrium sorption and first-order degradation rate coefficients. Centered implicit finite-difference method has been used to develop the numerical model for reactive solute transport through triple-permeability medium. A study has been carried out to investigate the behavior of breakthrough curves and temporal moments in the presence of mass transfer coefficients. Multi-peaked breakthrough curves have been observed for total and effluent solute concentration at large travel distance due to fast and slow flow in porous medium. In the presence of higher value of mass transfer coefficient, the magnitude of mean arrival time and second moment remains same for solutes in three regions of triple media. Higher value of first-order decay rate coefficient leads to reduce the magnitude of mean arrival time and second time moment for effluent concentration. However, higher value of retardation factor leads to increase the magnitude of mean arrival time and second moment for effluent concentration due to sorption of reactive plume in soil media. © 2018 Indian Society for Hydraulics.