Role of membrane surface morphology in colloidal fouling of cellulose acetate and composite aromatic polyamide reverse osmosis membranes

Menachem Elimelech, Xiaohua Zhu, Amy E. Childress, Seungkwan Hong

Research output: Contribution to journalArticle

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Laboratory-scale colloidal fouling tests, comparing the fouling behavior of cellulose acetate and aromatic polyamide thin-film composite reverse osmosis (RO) membranes, are reported. Fouling of both membranes was studied at identical initial permeation rates so that the effect of the transverse hydrodnamic force (permeation drag) on the fouling of both membranes is comparable. Results showed a significantly higher fouling rate for the thin-film composite membranes compared to that for the cellulose acetate membranes. Addition of an anionic surfactant (sodium dodecyl sulfate, SDS) to mask variations in chemical and electrokinetic surface characteristics of the cellulose acetate and aromatic polyamide membranes resulted in only a small change in the fouling behavior. The higher fouling rate for the thin-film composite membranes is attributed to surface roughness which is inherent in interfacially polymerized aromatic polyamide composite membranes. AFM and SEM images of the two membrane surfaces strongly support this conclusion. These surface images reveal that the thin-film composite membrane exhibits large-scale surface toughness of ridge-and-valley structure, while the cellulose acetate membrane surface is relatively smooth.

Original languageEnglish
Pages (from-to)101-109
Number of pages9
JournalJournal of Membrane Science
Issue number1
Publication statusPublished - 1997 Apr 30
Externally publishedYes



  • Colloidal fouling
  • Flux decline
  • Membrane fouling
  • Reverse osmosis membranes
  • Surface morphology
  • Surface roughness

ASJC Scopus subject areas

  • Biochemistry
  • Materials Science(all)
  • Physical and Theoretical Chemistry
  • Filtration and Separation

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