Bubble curtains for aquatic pollution control: A lattice Boltzmann study

Abstract

Abstract

This study presents a computational investigation of air bubble curtains for mitigating aquatic pollutant dispersion. A coupled framework based on the lattice Boltzmann method is employed, where the air–water flow is resolved by phase-field approach, while the pollutant concentration field is treated as passive scalar. The solver simultaneously captures interface dynamics, hydrodynamics, and scalar transport. Validation against benchmark problems demonstrates accurate interface representation and consistency with Laplace’s law. The hydrodynamic behaviour of single and double bubble curtains is investigated to elucidate the mechanisms governing pollutant blocking and leakage. Parametric studies are conducted using the dimensionless air inlet velocity ( F r a ∈ [ 0 0.149 ] ), the distance between pollutant source and bubble curtains ( γ ∈ [ 0 40 ] ), and the stand-off distance between double bubble curtains ( λ ∈ [ 2 30 ] ). The results show that bubble curtains act as dynamic barriers, limiting pollutant transport through the combined effects of discrete bubbles and the induced flow field. Increasing inlet velocity enhances bubble interactions and lateral deviation, reducing containment efficiency due to intensified advective transport. In contrast, increasing the stand-off distance markedly improves performance by suppressing cross-curtain transport. These findings provide physical insight into bubble curtain performance and guidance for environmental and coastal engineering applications.