The factors influencing the process of flocculation during aeration are analyzed. It is determined that the effect is due to the damping of small-scale pulsations of water during mixing, accelerated formation of nuclei of solid phases of coagulant hydrolysis products on the surface of air bubbles due to electrostatic and surface forces, as well as the release of excess amounts of carbon dioxide from the water. Theoretical dependences have been obtained showing that the dose of coagulant injected into the mixer with simultaneous aeration of water is proportional to the concentration of heterophase impurities and inversely proportional to the average particle size of contaminants, the gas saturation of the resulting water-air mixture and the velocity gradient.

Keywords: natural water, coagulant, mixer, aeration, coagulant dose, velocity gradient