Establishing the optimal conditions of the process of water treatment by ultrasound

The efficiency of water treatment from chemical and biological contamination using ultrasound in the presence of oxygen was investigated in the paper. It was found that the necessary water quality parameters are obtained already after an hour of acoustic cavitation action in the presence of oxygen. Oxidation of water-soluble organic compounds during sonication is the first-order reaction. Dispersion of microorganisms is heterogeneous system and oxidation is the pseudo-second-order reaction. High COD decrease efficiency during sonication of oxygen in the atmosphere is caused by the fact that peroxy radicals, peroxides and oxoradicals, participating in the radical-chain oxidation of organic compounds are generated under cavitation and provide high process speed.In aerobic conditions of storing dispersions, not treated with ultrasound, the COD value increases slowly, reaching a maximum for 6-10 days and remains constant. During storage of solutions with an excess of organic matter under aerobic conditions, the COD value decreased from 7181 mg/dm3 to 6504 mg/dm3 for 2 weeks. During storage of water, treated with ultrasound, the COD value remained constant for 2 weeks.After ultrasonic treatment of contaminated water, post-effect of acoustic cavitation, which lies in reducing the number of microorganisms per unit volume and COD occurs. In the US-treated water, growth of microorganisms starts only after 24 hours. The results allow to choose optimal conditions for the water treatment process and use ultrasonic units to treat sewage of the food industry enterprises or use mobile ultrasonic units for household purposes, such as cleaning private pools.