The impact of ultrasonic sound waves was initially noted by British maritime engineers in 1894. The sound waves produced by rotating propellers were referred to as hydrodynamic cavitation. In chemistry, researchers produce these sorts of sound waves by using powerful sound waves from an ultrasound generator with frequencies above 16 kHz . Researchers exposed water to ultrasound and observed that the heat from the bubble collapse breaks down water (H2O) into very reactive hydrogen atoms and hydroxyl radicals (OH -). Both atoms came back together to form hydrogen peroxide (H2O2) and molecular hydrogen (H2) during the cooling phase that followed . Within the bubble, localized temperatures and pressures reached 5000 K and 1000 atm, respectively, due to cavity implosion. Under these intense circumstances, it is frequently thought the formation of extremely reactive species including hydroxyl ( • OH), hydrogen ( • H), hydroperoxyl ( • HO2) radicals, and hydrogen peroxide, occurs . The presence of organic species or other substances in the irradiated water increases the likelihood of subsequent reactions. The degradation of organic substances is accelerated in these types of settings.