A novel membrane showing both hydrophilic and oleophobic surface properties and its non-fouling performances for potential water treatment applications

Abstract

Membrane organic and biological fouling has been one of the major problems for membrane technology applications in water and wastewater treatment. In this study, a novel membrane showing both hydrophilic and oleophobic surface properties was developed and evaluated for its resistance against organic and biological fouling. The membranes in flat sheet configuration were prepared from PVDF as the base matrix polymer, blended with an additive polymer that was synthesized to contain both hydrophilic and oleophobic segments. The prepared novel membranes displayed high affinity to water but low affinity to oil. Experimental results from the filtration of protein solution, humic acid solution and oil/water emulsion confirmed that the developed membranes had greatly enhanced water flux and reduced organic fouling performance (shown as slow flux decay and high flux recovery after membrane cleaning). In the biofouling tests with the developed membranes being immersed in bacteria suspension or used for the filtration of bacteria suspension, it was found that the novel membranes effectively prevented bacteria adhesion on the membrane and the flux decay incurred during the filtration can be fully recovered after a simple cleaning with water under the experimental conditions. This study also demonstrated that a membrane surface showing both hydrophilic and oleophobic surface properties provided an effective and better way to reduce the effect of membrane fouling by organic as well as biological foulants than a membrane surface showing the hydrophilic property only. The developed membrane has a great potential for water and wastewater treatment applications.