Blooms of algae that produce life-threatening toxins regularly plague water supplies around the world. In many cases, the algae’s toxins can survive standard treatments for purifying water. Researchers at Florida International University in Miami think they have a sound solution: ultrasound.
Blasting water with 640-kilohertz ultrasound waves briefly creates high-pressure microenvironments as hot as 3,700°C, which breaks some water molecules into reactive fragments that can kill the algae.