Processing and recycling of waste water is an important environmental problem. One possible and promising way to use the generated sludge is production biofertilizers for agriculture. However, in view of the risks of chemical and bacteriological contamination, it is necessary to develop technologies that ensure a high level of conditioning and stabilization of sludge. Maximum enzyme activity is observed in a microbubble medium under the conditions of a mesophilic process. To accelerate the biochemical transformation of pollutants, an enzyme-cavitation method has been developed, based on the stimulation of growth processes of microorganisms in bioreactors by low and high intensity cavitation created by turbojets. It has been established that the quality and duration of sludge treatment depends on the pressure of the substrate at the entrance to the oxidizing jets. It has been proven that at a pressure p = 0.30-0.35 MPa, the processing time of the sludge before stabilization of the chemical oxygen consumption at 16% is 8 hours. Microscopic studies found that the processed substrate is an accumulation of microorganisms with a total surface of up to 100 m2 per 1 gram of dry matter that provides high sorption properties with respect to moisture. © Published under licence by IOP Publishing Ltd.