A brief overview of the effects of ultrasound on the adsorption/desorption process: a review

Ultrasound has been succesfully and frequently used in many adsorption/desorption processes recently, since its beneficial effects on adsorption/desorption have been seen in scientific studies. The main positive effects can be listed as causing many micro-cracks on the solid surface, increasing the mass transfer rate and the surface area of reactants, and causing many positive mechanical effects, such as cleaning the surfaces of solid reactants or catalyst particles in solid-liquid systems. This review summarises ultrasound-assisted adsorption/desorption researches such as ultrasound-assisted prepared adsorbent for the removal of heavy metal cations from aqueous solutions, decolourisation and COD reduction of dye solutions, ultrasound-assisted zeolitisation of fly coal ash, etc. There are also some studies in which ultrasound power has been used for desorption instead of mixing and desorption by ultrasound is seen as an alternative method for adsorbent regeneration. In addition, in current review, the theoretical fundamentals of ultrasound-assisted adsorption/desorption procedures were explored briefly and the effect of ultrasound on adsorption isotherm and adsorption/desorption kinetics was also discussed.