EFFECT OF ULTRASOUND ON PH CHANGE IN WATER

Abstract

Introduction. The paper deals with physical and chemical effects in water, occurring under the action of the ultrasonic field based on the theory of cavitation bubble dynamics. The scope of the study is an aqueous environment, while ultrasound effects are chosen as the subject of the study. Methods. The paper describes equipment and a methodology for conducting experimental studies in a laboratory and suggests a layout of the experimental setup for ultrasonic liquid treatment, consisting of a generator, converter, and reactor. Results. It is shown that chemical transformations under the action of ultrasonic vibrations occur in an aqueous environment in the cavitation mode. The authors describe the appearance of active radicals in water as well as ionized hydrated electrons with neutral water molecules attached. They also introduce schemes of water splitting with the formation of active radicals that can change pH. It is noted that a cavitation cavity can serve as a source of intermediate products with high reactivity. The authors consider the principle of high temperatures occurrence during the adiabatic compression of a cavitation bubble. They also review a scheme of cavitation bubble formation in an aqueous environment with dissolved gases. An equation suggested by Ya. I. Frenkel, determining the field intensity in a bubble cavity at the moment of its formation, is shown. Physical parameters of the ultrasonic field for the occurrence of cavitation in an aqueous environment are given. The potentiometric method of water pH measurement is used. The authors also performed experimental studies and analyzed the data on water pH change in the ultrasonic field.