Microplastics (MPs) are widespread in aquatic environments, causing ecological issues worldwide. Microbubble (MB) technology has been extensively used in various industries due to its high efficiency, low cost, and sustainability, particularly in separation processes. However, its application in slurry flows containing solid particles, such as slurries with sands, remains underexplored. This study develops microbubble (MB)-enhanced separation of microplastics (MPs) in slurry flow containing 10 % sands in a pipeline. Key experimental parameters, including particle density, size and surface wettability of MPs, and bubble volume fraction, were systematically examined at the flow velocity of 2 m/s to compare the removal efficiency of MPs. As the volume fraction of bubbles in the flow varied from 0 to 0.5 %, the removal efficiency of aged polystyrene (PS) MPs was increased by 95 %. Computational fluid dynamics (CFD) simulations were performed to reveal the influence of MBs on the distribution of MPs in the slurry flow. The validated models predict that microbubbles promote accumulation of MPs near the pipe top by 7 times. Such localized accumulation of MPs in the slurry may be attributed to high removal efficiency by MBs. This work presents an innovative and efficient method for MB generated in-situ for markedly improved separation efficiency of MPs from slurry flows.
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