Degradation of gaseous vocs by ultrasonication: Effect of water recirculation and ozone addition

Ultrasonication with water recirculation slightly enhanced the removal of toluene compared to water recirculation alone due to conjunction of pyrolysis and hydroxyl radical oxidation with absorption. On the other hand, the addition of ozone with ultrasonication decreased the removal efficiency due to scavenging of hydroxyl radicals. The reaction rate for ozone and OH radicals produced during the US process was faster compared to the rate for ozone and toluene. © Springer Nature Switzerland AG 2020.