Mass Transfer Coefficient of Ozone in a Bubble Column

Abstract

Abstract. The effect of flow rate of ozone-containing gas and pH on the mass transfer coefficient of ozone through water in a bubble column reactor has been studied. Ozone was generated from air using a corona discharge ozone generator. The flow rate of air was varied from 2 to 5 L min -1 , while pH was varied from 4 to 10. The gas containing ozone was bubbled to the reactor containing 1.5 L of 2% KI solution. The temperature was set at 281C. The concentration of ozone was determined using titrimetric method every 5 minutes. The results show that the concentration of ozone increases with time, and it reaches a steady-state concentration after 30 minutes of ozonation. The gas flow rate and pH apparently affect both the concentration and the kLa. The highest kLa of 2.1 10 -2 s -1 is obtained at pH 4 with a gas flow rate of 4 L min -1 .

Heterogeneous Catalytic Ozonation of Aniline-Contaminated Waters: A Three-Phase Modelling Approach Using TiO2/GAC

“…The mass transfer coefficients obtained were of the same order of magnitude as those found by other authors [23,30,31], emphasizing the significant increase at pH = 7.0, where Rodríguez et al [23] obtained a coefficient of 0.073 min −1 .…”

Effectiveness of ozonation with zirconium and tin tetrachloride for stabilized anaerobic landfill leachate treatment

“…Physical observation clearly showed that the bubbles produced in 2‐L/min flow rate were finer than those produced in 1.2‐L/min flow rate. Therefore, a high concentration of O 3 at a flow rate of 2‐L/min flow is expected to produce a small gas bubble through a 2‐mm fine ozone nozzle and maximize the O 3 solubility into the sample through gas–liquid films, as mentioned in the two film theories (Ratnawati et al, 2018). Lage Filho (2010) pointed out that fine bubbles present a large surface area for O 3 gas to be transferred or dissolved in the liquid phase.…”

“…Lage Filho (2010) pointed out that fine bubbles present a large surface area for O 3 gas to be transferred or dissolved in the liquid phase. This phenomenon can be described in Equation (Ratnawati et al, 2018). where kLa is the volumetric mass transfer coefficient of ozone, and C and C * are the concentrations of ozone at time t and at saturated conditions, respectively.…”

“…Lage Filho (2010) pointed out that fine bubbles present a large surface area for O 3 gas to be transferred or dissolved in the liquid phase. This phenomenon can be described in Equation 16 (Ratnawati et al, 2018).…”

The enhancement of ozone–liquid mass transfer performance in a PTFE hollow fiber membrane contactor using ultrasound as a catalyzer

“…The obtained results indicated that the helical structure of the hollow fibers of the ozone–liquid membrane contactor contributed to the high ozone flow rates and high ozone dissolved concentration, increasing the mass transfer coefficient. Ratnawati et al 28 studied the effect of the ozone-containing gas flow rate (over a range of 2–5 L min −1 ) and pH (over a range of 4–10) on the ozone mass transfer coefficient in a bubble column reactor. The obtained results indicated that a maximum K L a of 2.1 × 10 −3 s −1 at pH 4 with a gas flow rate of 4 L min −1 was obtained.…”