EFFECTIVE ACTION OF CAVITATION TREATMENT OF CONTAMINATED WATER
Abstract
Traditional water treatment methods, such as chemical coagulation, adsorption, chlorination, and biological treatment, do not always provide the necessary level of disinfection and can have negative side effects, including the formation of toxic byproducts. The results of experimental studies on the effect of argon and helium (gas bubbling rate – 0.2 cm³/s) through a water medium (volume of 75 cm³) and ultrasonic cavitation (22 kHz, 35 W) on Saccharomyces cerevisiae yeast over a two-hour period are described. The number of microorganisms in the studied water was determined based on the total number of colonies grown on nutrient media in Petri dishes. A significant reduction in cell count was observed at the initial stage of the process under the action of argon and cavitation (61.84% after 30 min) at an initial microbial contamination of 2.07×10⁴ CFU/cm³, leading to the elimination of over 98% of the cells after one hour of treatment. Under the influence of helium and cavitation, a reduction in Saccharomyces cerevisiae was also observed in the early stages of the process: the fraction of dead cells (Dd) reached 40.48% after 30 min at an initial microbial contamination of 4.2×10³ CFU/cm³. After 90 minutes of treatment, the microorganism concentration decreased to 100 CFU/cm³, corresponding to a water purification level of over 97%. The calculated rate constant of cells destruction for the studied gases indicates the higher efficiency of argon compared to helium under cavitation conditions. The greater effectiveness of argon is explained by its physicochemical properties, particularly its lower thermal conductivity and ionization potential, which promote more intense cavitation bubble formation and active microbial destruction. The obtained results confirm the feasibility of using the combined action of ultrasound and inert gases for effective water disinfection and its subsequent discharge into natural water bodies. Further research in this area may focus on optimizing the parameters of cavitation treatment, specifically investigating the effect of variable-frequency ultrasonic cavitation on different types of microorganisms and determining the optimal balance between ultrasound power, treatment duration, and gas sparging rate.
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