Keywords: bubble-particle interaction, bubble-particle capture, dissolved air flotation, DAF, double-layer force, DLVO forces, hydrophobic attraction, microhydrodynamic resistance, non-DLVO forces, van der Waals force, air microbubbles, wastewater treatment, water pollution, environmental pollution
One-step analysis of bubble-particle capture interaction in dissolved-air flotation
The capture of particles by air microbubbles in dissolved air flotation has been analysed using a one-step (holistic) approach, which numerically solved the motion equation (with the inclusion of microhydrodynamic resistance functions and surface forces) for both the bubble-particle collision and attachment interactions. Model predictions with the inclusion of non-DLVO attractive surface force agreed with the experimental trajectories of latex particles. The non-DLVO attractive force reduced the force barrier between non-attaching particles and bubbles, and significantly increased the attractive net force between attaching particles and air bubbles.