A new method of dissolved air (pressure) flotation with the spraying of liquid is presented in the paper. The liquid to be treated is sprayed in the saturator with a hydraulic nozzle which makes it possible to increase the contact surface between the liquid and the gas in comparison with the traditional sparged-air saturator system. The proposed method increases the gas content of the liquid entering the flotation unit for treatment. The paper presents the results of experimental research in terms of the efficiency of liquid saturation in a pressure vessel using whirl and spiral nozzles. The volumetric method was used to determine the amount of air released during the dissolved air flotation based on which the sparging rate was calculated. It is shown that, when the liquid is sprayed, the amount of dissolved air increases by an average of 33% compared to a sparged-air pressure vessel. The sparging rate increases with the increase of saturation pressure and essentially depends on the area of the flotation unit. At the saturation pressure above 2 bar, the sparging rate in the center of the flotation unit becomes significantly higher than that in the wall-adjacent area.
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