A nonlinear attachment-detachment model with adsorption hysteresis for suspension-colloidal transport in porous media

In this study, we propose a nonlinear attachment-detachment model with hysteresis for the transport of suspension-colloidal particles (SPs) in porous media. The proposed model uses an adsorption function and scanning desorption isotherms to model the deposition process of SPs. This model shows that increasing or decreasing the seepage velocity results in substantial changes in the penetration concentration of SPs, which is closely related to the adsorption hysteresis and the deposition dynamics of SPs. Studies show that previous linear attachment-detachment models probably result in an overestimation of the adsorption capacity of porous media. Static deposition tests and dynamic transport experiments using pulse injection were performed to calibrate the transport parameters. The effects of the seepage velocity, injection concentration and particle size on the transport parameters and reaction rate constant were investigated. Experiments were also performed under variable injection concentrations and seepage velocities. The results show that there is good agreement between the simulated and experimental breakthrough curves (BTCs).