Comparative analysis of fouling characteristics of ceramic and polymeric microfiltration membranes using filtration models

Ceramic membrane processes are a rapidly emerging technology for water treatment, yet virtually no information on the performance and fouling mechanisms is available to the industry considering them as an alternative to polymeric membrane processes. Ceramic microfiltration of model feed solutions containing polyethylene glycol or Suwannee River humic acid as well as a synthetic river water was examined, and a systematic comparison with polymeric membrane filtration was performed. The fouling characteristics of ceramic membranes were investigated for the first time using filtration models including the combined pore blockage-cake filtration model, constant pressure filtration laws, resistance-in-series model, and the unified membrane fouling index model. The results suggested that the above models which have been applied to polymeric membranes agreed well with the ceramic membrane filtration results. The fouling was characterized by the initial pore blocking mechanism and transitioned to the cake filtration mechanism at a later phase of filtration. Cake resistance was the dominant form of the total resistance for ceramic membranes under the conditions tested in this study and was readily removable by physical cleaning. The results of this study provide basic information upon which further in-depth studies can be built, including the effects of water quality, membrane characteristics, and operating conditions.