Effect of intermittent back ozonation for membrane fouling reduction in microfiltration using a metal membrane Original Research Article

In a microfiltration system using a metal membrane for municipal raw sewage reclamation, the following research points were mainly investigated: 1) Effect of intermittent back ozonation for membrane fouling reduction, 2) effect of operational parameters for permeation flux, and 3) the estimation of optimal operational conditions using an empirical model in the case of back ozonation. Intermittent back ozonation dramatically improved the membrane fouling. The permeation flux was recovered up to 90% of initial flux with dosage of 0.27 (mgO3/cm3/cycle). Among operational parameters, we found that ozone concentration was the most influential parameter for membrane fouling reduction. In the case of back ozonation, the optimal values of each operational parameter with respect to ozone concentration, ozone gas flow rate and injection time to satisfy 90% recovery of initial flux were 20.2 (mgO3/L), 3.1 (L/min) and 2.1 (min), respectively. Intermittent back ozonation is believed to be an innovative and feasible technology for fouling reduction and high permeation flux in case inorganic membrane material is being used.