In Situ Dynamic\nStructural Evolution of Microchannels\nunder Sustained Pressure: Anisotropy, Transportation, and Applications

The particulate matter released from fossil fuel combustion\nis\na significant pollutant in chemical and environmental engineering.\nFiltration, distinguished by its high separation efficiency and avoidance\nof secondary pollution, offers a robust strategy for particulate separation.\nHowever, the effect of porous media heterogeneity on multiphase flow\nbehavior in the filtration process has not been comprehensively characterized.\nHere, the pore structure characteristics of fiber filters were experimentally\ninvestigated under different compressive load pressures using time-lapse\nsynchrotron X-ray microtomography. In situ dynamic evolution experiments\nrevealed that pressure changes during the filtration processes can\nalter the pore structure, enhancing pollutant transfer and strengthening\nsurface interactions. These effects facilitate the separation of pollutants\nfrom water. Through simulation, it was found that under the same pressure\ngradient conditions, differences were observed in microchannel seepage\nat different angles. In addition, the pore pressure was found to gradually\ndecrease along the seepage flow-path, with significant pressure changes\nobserved due to the reduction in pore size and curvature. These findings\nhave important implications for our understanding of the pore-level\nfluid migration behavior of porous media systems, supporting the development\nand improvement of particle filtration and separation technologies.