Effect of the metal oxide particle distributions on modified PES membranes characteristics and performance

In this study, the effect of metal oxide particle distribution pattern on the performance and physical characteristics of 0.03, 0.05 and 0.1 Al2O3/PES and ZrO2/PES composite membranes was investigated. Membrane morphology was characterized by field-emission scanning electron microscopy (FESEM) and the metal oxides particles distribution patterns were determined using Image J software (U.S. National Institutes of Health, Bethesda, MD, USA). The prepared metal oxides/PES membranes were skin-type membranes and showed a structural change from finger- to sponge-type structure. The finger structure was associated with high metal oxides percentage of the total metal oxide particles entrapped in the membrane (60–95% and 52–100% for Al2O3/PES and ZrO2/PES, respectively) in the membrane matrix. No statistical correlations have been observed between either the particles densities at the 0–10 or 10–20 μm depths and membrane physical characteristics or performance parameters. However, strong inverse correlations were observed between the metal oxides particles densities at the membranes depths of 30–40 and 40–50 μm, respectively, and membrane fouling resistances (Rf). According to the constant pressure models, the experimental results for sludge filtration using all tested membranes were in good agreement with the standard blocking model (SBM).