Mixing Time of Cylindrical Bath Agitated by Swirl Motion of Gas-liquid Two-phase Jet and Sludge Treatment Using Ozone

Abstract

Sludge treatment using a gas-liquid two-phase swirling jet and ozone was proposed. The swirl motion of a gas-liquid two-phase jet appeared in a cylindrical bath under certain injecting conditions, and the bath was strongly agitated in the presence of the swirl motion. The swirling jet brought a very excellent effect on the ozone reaction with sludge. The intensity of agitation was quantitatively evaluated by means of mixing time. An empirical equation was derived for the mixing time. Sludge was decomposed by this method and, as a result, BUD₅ and SS in the sludge were significantly decreased.