Absorption and decomposition of ozone in a three-phase split-rectangular airlift reactor under ultrasonic irradiation

Ozone absorption was investigated in a three-phase split-rectangular airlift reactor under ultrasonic irradiation using γ-Al2O3 as catalyst. The reactor consisted of a square column (50 × 50 mm) with the height of 120 mm, divided into a riser and a downcomer by a baffle, 50 mm in width, 4 mm in thickness and 50 mm in total height. An absorption kinetic model was proposed to determine the volumetric mass transfer coefficient of ozone kLaA. The results showed that kLaA increased from 0.409 to 0.712 min(-1) as power density rose from 27.2 to 100.3 W L(-1), comparing with 0.242 min(-1) in the absence of ultrasonic irradiation. The increase in gas flow rate and catalyst loading also favored the increase of kLaA. The degassing effect due to ultrasonic irradiation could be ignored in the ozone absorption process.