Simulation of Dynamic Evolution for Oil-in-Water Emulsion Demulsification Controlled by the Porous Media and Shear Action

With oily wastewater treatment emerging as a critical global issue, porous media and shear forces have received significant attention as environmentally friendly methods for oil–water separation. This study systematically simulates the dynamics of oil-in-water emulsion demulsification under porous media and shear forces using a color-gradient Lattice Boltzmann model. The morphological evolution and demulsification efficiency of emulsions are governed by porous media and shear forces. The effects of porosity and shear velocity on demulsification are quantitatively analyzed. (1) The presence of porous media enhances the ability of the flow field to trap oil droplets, with lower porosity corresponding to improved demulsification performance. Moreover, a more orderly arrangement of porous media promotes oil droplet coalescence. (2) Higher shear velocity in the flow field facilitates the aggregation of oil droplets. However, oscillatory shear conditions reduce the demulsification efficiency of emulsions. (3) Among the combined effects of shear velocity and porosity, porosity emerges as the dominant factor influencing emulsion demulsification. (4) Higher initial oil concentrations enhance demulsification efficiency. These simulation results provide valuable insights for further research on emulsion demulsification.