In Situ Dynamic Structural Evolution of Microchannels under Sustained Pressure: Anisotropy, Transportation, and Applications

The particulate matter released from fossil fuel combustion is a significant pollutant in chemical and environmental engineering. Filtration, distinguished by its high separation efficiency and avoidance of secondary pollution, offers a robust strategy for particulate separation. However, the effect of porous media heterogeneity on multiphase flow behavior in the filtration process has not been comprehensively characterized. Here, the pore structure characteristics of fiber filters were experimentally investigated under different compressive load pressures using time-lapse synchrotron X-ray microtomography. In situ dynamic evolution experiments revealed that pressure changes during the filtration processes can alter the pore structure, enhancing pollutant transfer and strengthening surface interactions. These effects facilitate the separation of pollutants from water. Through simulation, it was found that under the same pressure gradient conditions, differences were observed in microchannel seepage at different angles. In addition, the pore pressure was found to gradually decrease along the seepage flow-path, with significant pressure changes observed due to the reduction in pore size and curvature. These findings have important implications for our understanding of the pore-level fluid migration behavior of porous media systems, supporting the development and improvement of particle filtration and separation technologies.