Using ultrasound for restoring iron activity in permeable reactive barriers

Ultrasound application has been shown to be an effective treatment for increasing reactivity of iron used in permeable reactive barriers (PRBs). Since iron goes through corrosion reactions during the remediation process, precipitates form on the iron surface thus leaving the permeable reactive barrier less effective and can even alter groundwater flow around the wall. After several years of laboratory study, ultrasound was used at two different PRB field sites. Results show that ultrasound application improves half-lives from 21-67% (dependent on transducer power and duration of exposure) over untreated iron samples from the same PRB treatment site