Ultrasonic Treatment of Organic Dyes: Effects and Mechanisms Publisher



Hamidi F ; Mirtaleb ST ; Yazdi NB ; Ahmadi M ; Sheikhi S ; Bashardoust P ; Dehghani MH
Source: Ultrasonic Treatment of Water and Wastewater: Removal of Biological and Chemical Pollutants and Combined Processes Published:2026

Abstract

This review focuses on elucidating the effects and mechanisms of ultrasound waves on organic dye molecules, highlighting their potential as a tool for the treatment and modification of dyes. Extensive research has focused on the use of ultrasound waves to induce physical and chemical transformations in organic dyes. Ultrasound’s direct physical effects, such as cavitation and acoustic streaming, enhance the movement, dispersion, and transfer of dye molecules. Cavitation, characterized by the creation and collapse of gas-filled bubbles, generates localized shock waves that effectively break down larger dye molecules into smaller fragments, leading to improved color removal and degradation. Ultrasound waves have a chemical impact on organic dye molecules, promoting chemical reactions like sonochemical degradation and sonophotocatalysis, which break down complex dye structures. Additionally, ultrasound increases the efficiency of advanced oxidation processes by producing reactive oxygen species that actively contribute to the degradation of organic dyes. The behavior of organic dyes under ultrasound waves depends on factors like frequency, intensity, exposure time, and dye properties, while the selection of solvent and the presence of catalysts or additives can augment the degradation efficiency. Additionally, certain dye molecules are more prone to ultrasound treatment based on their structural attributes, including reactive functional groups. Recent studies have revealed the mechanisms underlying the response of organic dyes to ultrasound waves, including sonochemical reactions, free-radical generation, molecular fragmentation, and chemical degradation pathways, with the development of ultrasound-assisted techniques like ultrasound-assisted adsorption and ultrasound-assisted photocatalysis to enhance treatment efficiency. In this chapter, we try to explain the factors that affect the removal of organic dyes by ultrasound waves. © 2026 Elsevier Inc. All rights reserved.