Abstract
It is important to separate and collect particles from solid–liquid mixtures to reduce the environmental load and treatment costs of waste fluid. In this study, we attempted to separate and collect particles from mixtures using relatively low-frequency ultrasound. Here, we report the behavior of particles determined using a high-speed video camera and analyzed by time series image analysis correlated with sound pressure distribution. The particles were fully stirred in test water and then ultrasonicated at various frequencies. Particles flocculated to a number of layers appearing like white bands corresponding to the nodes of sound pressure after ultrasonication. Particles began to move just after ultrasonication and flocculated clearly with increases in sound pressure.
