A double-distribution function Lattice Boltzmann Method (LBM) is used to simulate the seepage and adsorption process of solution flow through porous media with an adsorbent at the pore scale. The accuracy of the model is verified by simulating the interfacial adsorption and intraparticle diffusion processes. The effects of inlet and outlet density difference, inlet concentration, and adsorbent packed bed height on the permeability and adsorption process of two-dimensional porous media with adsorbent are discussed. The numerical simulation results show that the adsorption equilibrium time increases with the increase in inlet and outlet density difference and inlet concentration, and the thicker the adsorption layer, the lower the adsorption rate. The seepage rate increases with the increase in inlet and outlet density difference and the increase in adsorbent packed bed height, but the change in inlet concentration has no effect on it. The flow resistance in the adsorbent particles has a great influence on the mass transfer process, so it should be considered accurately. The LBM model proposed in this paper is an effective tool to study the remediation of seepage pollution in porous media such as soil and groundwater.

The aerator can reduce erosion by mixing a large amount of air into the water in the solid wall area. The effectiveness of erosion reduction is mainly based on air concentration and its bubble size distribution. However, simultaneous simulation of the air concentration and its bubble size distribution in numerical simulations is still a hot and difficult area of research. Aiming at the downstream aerated flow of hydraulic aeration facilities, several numerical models, such as VOF, mixture, Euler, and Population Balance Model (PBM), are compared and verified by experiments. The results show that the CFD-PBM coupled model performs well compared to other conventional multiphase models. It can not only obtain the evolution law of the bubble distribution downstream of the aerator but also accurately simulate the recombination and evolution process of bubble aggregation and breakage. The Sauter mean diameter of the air bubbles in the aerated flow decreases along the way and eventually reaches a stable value. The bubble breakage is the main process in the development of the bubbles. It reveals the aeration law that the small air bubbles are closer to the bottom plate, while the large bubbles float up along the aerated flow, which provides a powerful support for the basic research on the mechanism of aeration and erosion reduction.