High linear correlation (R2= 0.964 for GR60PP and R2= 0.989for OT050) between the tap water flux and the TMP (Fig. 2)was found. The slope of the line corresponds to the hydraulicpermeability to pure water (Lp), which characterizes the mem-brane in the filtration process. It was 132.30 L/m2h bar for theOT050, whereas of only 33.52 L/m2h bar for the GR60PP. Thiscan be attributed to the larger porosity of the OT050 mem-brane, which is 27% higher than that of GR60PP