Abstract
The generation of cavitation through ultrasonic waves can lead to the formation of reactive species, such as · OH and H2O2 in aqueous liquids. These short-lived species are capable of effecting secondary oxidation or reduction reactions, which are referred to as sonochemical reactions. This paper reports a new method of cavitation diagnostics with an electrochemiluminescence (ECL) optical sensor for studying any sonochemical activity induced by ultrasonic cavitation. This system has been successfully employed to determine the actual rate production of H2O2 and the sonochemical efficiency (SE value) in different sonochemical reactors with frequencies of 28, 45, 100 and 490 kHz, respectively. The SE values were in excellent agreement with results evaluated by potassium iodide (KI) dosimetry. Because of the high sensitivity of this method, the potential modulated ECL sensor was capable of measuring the hydroxyl radical production (in this case hydrogen peroxide) in situ, so as to obtain the spatial distribution of cavitation generated in the ultrasound field.
