These scanning electron microscope images show particles of cinnabar before sonication (above) and after (below). Ohio State University scientists are developing a technique to clean mercury from contaminated sediment. In this technique, ultrasonic waves vibrate sediment particles so that the mercury is released into the water, then algae absorbs the mercury form the water. Here, cinnabar (mercury sulfide) is used in the laboratory to demonstrate the process. Images courtesy of Ziqi He, Ohio State University.