No abstract

Clogging and gel-layer formation during membrane filtration affect the concentration of ions in the filtrate as well as the concentration of suspended solids. The flow rate analysis and the observation of the filter surface with a scanning electron microscope show that a gel-layer is formed subsequently after the clogging. Humic acids, fulvic acids, metal hydroxides, and soft particles dispersed in natural waters cause the clogging and hence the gel-layer formation. Cross-flow filtration decreases the rate of the clogging and the gel-layer formation and gives little rise to the filtration effects on analytical results.