USING HYDRODYNAMIC CAVITATORS FOR WASTEWATER POST-TREATMENT AND DESINFECTION

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-08-9 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 51, 1071-1076 pp, DOI: 10.5593/sgem2017/51/S20.140

ABSTRACT

The article discusses an urgent problem of developing wastewater treatment technologies that ensure high efficiency with simultaneous reduction of energy consumption and mass and size of a plant. Cavitation treatment is one of the modern and promising physico-mechanical wastewater treatment methods. Cavitation is a rupture of dropping liquid under the action of tensile stresses due to the change of characteristics of the velocity and pressure fields occurring at rarefaction in the considered point of the liquid. During the rupture of dripping liquid cavitation bubbles (cavities) form filled with steam, gas or their mixture. Due to intensive vibration and high temperature at a single point, cavitation destroys actively organic compounds, colloids, cell membranes of microorganisms. Therefore, cavitation treatment may be an effective instrument for post-treatment and disinfection of waste waters. In this research an ejector-cavitator with a torus-shaped chamber combining features of a hydrodynamic cavitator, a water ejector and a mixer was studied. This unit is installed on a pump pressure line, it does not contain moving parts, ensures low energy consumption, has small weight and size parameters, and according to the results of the experiments, works reliably in a wide range of pressures and flow rates. The conducted researches proved the effect of wastewater disinfection and revealed a synergistic effect at a combined usage of cavitation and ozone.

Keywords: hydrodynamic cavitators, wastewater post-treatment and desinfection, physico-mechanical wastewater treatment methods, ozone-air mixture ejection