Abstract. 1 The effectiveness of wastewaters treatment by means of ultrasonic and vibration response cavitation has been investigated. The application of the vibration and cavitation equipment produces the same effects as in case of ultrasonic cavitation, but it is economically reasonable to use vibration response low-frequency cavitators.

The influence of cavitation on a decrease of the number of microorganism colonies has been investigated. Our results have shown that the number of viable microorganisms in water dispersion during first 30 minutes of sonication increased till maximum. Then their quantity sharply decreased. A kinetic model of ultrasonic degradation of yeast cells aggregates was proposed.

The regularities of the change of the concentration of microorganisms and water-soluble organic compounds in the polluted water in the conditions of cavitation treatment and the influence of the amount of biological water pollution on the value of the chemical oxygen consumption are investigated.