The effects of ultrasound on cyanobacteria

► Ultrasound at different frequencies and powers can be used to control blue green algae. ► Low power ultrasound can declump and stress algae leading to death. ► High power ultrasound can disrupt algae structure. ► Ultrasound can destroy liberated toxins. The use of ultrasound for the control of algae and in particular for Microcystis aeruginosa has been investigated. The results indicate that sonication may provide a more environmentally friendly and more effective method for the control of cyanobacteria blooms than conventional treatments. Algae blooms occur frequently and globally in water bodies and are a major concern in terms of their effects on other species such as plants, fish and other microorganisms together with the potential danger to human health from cyanobacterial toxins that are carcinogenic. In addition to removing the algae itself ultrasound can also degrade such toxins. A range of ultrasonic conditions (in terms of frequency and intensity) have been studied under laboratory conditions together with a small number of pilot (field) studies that confirm the potential for ultrasonic treatment of algae on a large scale.