Enhancement of ozone dissolution and oxidation treatment of phenolic wastewater by a static spiral shear rig with a variable screw pitch

Abstract

A novel static spiral shear rig (SSSR) with variable screw pitch was developed to enhance the ozone–water mass transfer and the oxidative degradation of phenolic wastewater. The effects of critical operational parameters on the dissolution and mass transfer of ozone in water and the oxidative degradation rate of phenol were investigated with the proposed SSSR. Moreover, the mass transfer and oxidative degradation of phenols with the SSSR were compared to conventional static mixer (CSM) methods. The results showed that the mass transfer coefficient obtained with the SSSR is 5.33 times greater than that obtained with CSM. With the SSSR, the degradation percentage of phenolic wastewater with an initial concentration of 100 mg/L reached 97.09% within 12 min, and the reaction kinetic constant for phenol degradation obtained with the SSSR is 3.68 times higher than that obtained with the CSM. The SSSR dramatically enhances ozone dissolution and mass transfer, resulting in a higher phenol oxidative degradation percentage and a constant kinetic reaction.