Ultrasonic treatment for microbiological control of water systems.

A combination treatment of shear, micro-bubbles, and high-frequency low-power ultrasound introduced via side-stream treatment of industrial water systems has shown excellent results in controlling bacteria and algae. Through the physical, high-stress environment created by ultrasonic waves, sessile and planktonic biological populations, some of which may undergo programmed cell death (PCD), can be controlled. Additionally, the instability and reduction of biofilm have been observed in systems treated by ultrasound and may be attributed to starvation-stress and lack of available cross-linking cations in the biofilm.