Understanding fouling dynamics on functionalized CNT-based membranes : Mechanisms and reversibility

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

49 Scopus Citations
View graph of relations

Related Research Unit(s)


Original languageEnglish
Pages (from-to)74-84
Journal / PublicationDesalination
Online published25 Jan 2019
Publication statusPublished - 15 Apr 2019


Herein, we explored resistance to fouling and the bactericidal potential of a functionalized carbon nanotube (CNT)-based polyvinylidene fluoride (PVDF) membrane. Humic acid (HA), a main constituent in natural organic matter was used as an indicator for the estimation of organic fouling, while Escherichia coli was employed as a model bacterium for biofouling investigation. In-situ fouling characterization was performed using a non-destructive optical coherence tomography. Results revealed that a thin CNT layer on the PVDF surface effectively prevented HA molecules from interacting directly with the porous structure of membrane, thereby averting the possibility of pore blockage (irreversible fouling). Moreover, the CNT membranes offered higher permeability, increased HA rejection, and better flux restoration capacity as compared with pristine PVDF membrane. This superior anti-HA-fouling performance of CNT membrane was accredited to the electrostatic repulsions between the CNT layer and HA molecules, both carrying a strong negative charge and high density of hydrophilic functional groups on the CNT surface. Antibacterial results from the ultrastructural examination of cell membrane integrity authenticate the bactericidal potential of CNT membrane toward biofouling causing bacteria. Finally, when tested with real sea water, CNT membrane with less organic and biofouling propensity outperformed commercial PVDF, indicating their suitability for seawater reverse osmosis (SWRO) pretreatment.

Research Area(s)

  • Antibiofouling, Carbon nanotubes, Irreversible fouling, Optical coherence tomography, SWRO pretreatment