Experimental studies have been conducted on a method for obtaining a highly dispersed water-air mixture for flotation wastewater treatment using vortex mixing devices. In the course of experimental studies, the patterns of changes in the circumferential (radial) flow velocities of a single-phase liquid (pure water) in the annular space of the barrel of a vortex mixing device at different diameters of the central rod were determined. Experimental studies were carried out at different heights of the H trunk (0.5 m, 1 m, 1.5 m and 2 m) with and without enamel coating of the flow part

Keywords: flotation, dispersion, vortex mixing device, axial velocity, circumferential velocity, trajectory angle of incidence, enamel coating

The effectiveness of various inorganic coagulants based on aluminum and iron was evaluated. Based on a review of the literature data, as well as experimental studies, the advantages and disadvantages of a number of coagulants based on aluminum and iron have been identified. Aluminum sulfate, iron sulfate, as well as polyoxychloride and aluminum oxychloride were studied. Based on the results of evaluating the effectiveness of inorganic coagulants in terms of turbidity, chromaticity, residual aluminum, permanganate oxidability, recommendations for their separate and joint use are given.

Keywords: coagulant, aluminum, iron, turbidity, chromaticity, permanganate oxidability, residual aluminum