Electrochemical determination of the active zones in a high-frequency ultrasonic reactor

In order to design a new reactor based on sonoelectrochemical technology for processes of wastewater treatment, mass transfer is studied in a high-frequency (560 kHz) ultrasonic reactor. The determination of the active zones is of particular interest because it allows to locate the electrodes where mass transfer is highest. The determination of the mass-transfer coefficient was achieved by measuring the diffusion current obtained in the electrochemical reduction of potassium ferricyanide, Mean mass-transfer coefficients k(d) are calculated at different points throughout the reactor and a spatial distribution of k, is obtained which represents the active zones of the reactor. This spatial distribution is in good agreement with the one obtained recently by chemiluminescence measurements and confirms the difference existing between the spatial distribution obtained by sonication at low frequency (20 kHz) and high frequency (500 kHz) ultrasound.