Steam cleaning for control of membrane fouling in ceramic membrane system

ABSTRACT In this study, the recovery efficient by operating pressure and influent water quality was evaluated in order to develop cleaning process for ceramic membrane using high temperature steam. The operating pressure was fixed at 100, 200, and 300 kPa during filtration time and the change in permeate flux and resistance was measured over time. The artificial water was made by adjusting the concentration of turbidity (25, 50, 100 NTU) and dissolved organic carbon (DOC) (4, 8 mg/L) using kaolin and humic acid. As a result of evaluating the steam injection time for 0–5 min in order to derive the optimum conditions of steam cleaning, the efficiency of 35%–54% was improved compared with the physical washing when steam was injected for 3 min. It was confirmed that steam cleaning at high turbidity and high organic matter condition increased cleaning recovery rate of 15.1%–53.8% compared with physical backwashing. As a result of analyzing the membrane fouling formed by using the resistance in series model, it was confirmed that the steam cleaning improves the cleaning efficiency by converting 3.8%–39.2% of irreversible fouling (R f ) into reversible fouling (R c ) depending on conditions. In the ceramic membrane process, the steam cleaning showed better efficiency than the physical backwashing. Steam cleaning can be expected to improve the stability of the process and reduce the chemical costs.