An alternative technique for determining the number density of acoustic cavitation bubbles in sonochemical reactors

Aissa Dehane; Slimane Merouani; Oualid Hamdaoui; Muthupandian Ashokkumar

doi:10.1016/j.ultsonch.2021.105872

An alternative technique for determining the number density of acoustic cavitation bubbles in sonochemical reactors

Ultrason Sonochem. 2022 Jan:82:105872. doi: 10.1016/j.ultsonch.2021.105872. Epub 2021 Dec 10.

Authors

Aissa Dehane¹, Slimane Merouani², Oualid Hamdaoui³, Muthupandian Ashokkumar⁴

Affiliations

¹ Laboratory of Environmental Engineering, Department of Process Engineering, Faculty of Engineering, Badji Mokhtar - Annaba University, P.O. Box 12, 23000 Annaba, Algeria.
² Laboratory of Environmental Process Engineering, Department of Chemical Engineering, Faculty of Process Engineering, University Constantine 3 Salah Boubnider, P.O. Box 72, 25000 Constantine, Algeria. Electronic address: s.merouani@yahoo.fr.
³ Chemical Engineering Department, College of Engineering, King Saud University, P.O. Box 800, 11421 Riyadh, Saudi Arabia.
⁴ The University of Melbourne, Department of Chemistry, Parkville, VIC 3010, Australia.

Abstract

The present paper introduces a novel semi-empirical technique for the determination of active bubbles' number in sonicated solutions. This method links the chemistry of a single bubble to that taking place over the whole sonochemical reactor (solution). The probe compound is CCl₄, where its eliminated amount within a single bubble (though pyrolysis) is determined via a cavitation model which takes into account the non-equilibrium condensation/evaporation of water vapor and heat exchange across the bubble wall, reactions heats and liquid compressibility and viscosity, all along the bubble oscillation under the temporal perturbation of the ultrasonic wave. The CCl₄ degradation data in aqueous solution (available in literature) are used to determine the number density through dividing the degradation yield of CCl₄ to that predicted by a single bubble model (at the same experimental condition of the aqueous data). The impact of ultrasonic frequency on the number density of bubbles is shown and compared with data from the literature, where a high level of consistency is found.

Keywords: Acoustic bubbles; CCl(4) pyrolysis; Number density; Single bubble sonochemistry; Sonochemical reactors.