Enhanced microbubbles assisted cleaning of diesel contaminated sand.

In this article, we investigated the effect of low intensity pulsed ultrasound (US), temperature and salinity on cleaning efficacy of fine bubbles with diameter <50μm for diesel contaminated sands. About 47% and 76% diesel removal was achieved from 10% (w/w) diesel contaminated fine and medium sands respectively, after 30min treatment with 40kHz low intensity intermittent pulsed US together with MBs in contrast to 41% and 68% diesel removal while treatment with MBs alone. The effect of high temperature was found to be prominent during the initial stages of cleaning. In addition, MBs generated in 599mM saline water efficiently removed 85% diesel from fine sand within 30min in contrast to only 41% diesel removal with MBs in fresh water. This study provides evidence for developing highly efficient MBs based chemical free technology for diesel contaminated sediments.