Use of an ejector for phenol containing water treatment by ozonation

Mass transfer of ozone in aqueous phase is a major aspect of ozonation and advanced oxidation processes. The aim of this study is to compare the performances of an ejector with those of a more traditional gas/liquid contactor: a bubble column. The hydrodynamic study showed that the volumetric mass transfer coefficient of the ejector (KLa = 7.2 × 10−2 to 1.35 × 10−1 s−1) was greater than that of the bubble column's (KLa = 1.5 × 10−2 to 2.8 × 10−2 s−1). Very important differences in the values of the residence time and gas retention rate were also observed. A study of phenol degradation was performed. Due to its specifications the ejector is very efficient when the kinetics of reaction is fast (diffusion-controlled regime). In both semi-batch and open circuits, the phenol was quickly eliminated and the ozone transfer was very high (up to 98%). It is to be noted that these results were obtained for a processing time of approximately 1 s.