Viscoelastic properties of extracellular polymeric substances can strongly affect their washing efficiency from reverse osmosis membranes

Diana Lila Ferrando Chavez, Ali Nejidat, Moshe Herzberg

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

The role of the viscoelastic properties of biofouling layers in their removal from the membrane was studied. Model fouling layers of extracellular polymeric substances (EPS) originated from microbial biofilms of Pseudomonas aeruginosa PAO1 differentially expressing the Psl polysaccharide were used for controlled washing experiments of fouled RO membranes. In parallel, adsorption experiments and viscoelastic modeling of the EPS layers were conducted in a quartz crystal microbalance with dissipation (QCM-D). During the washing stage, as shear rate was elevated, significant differences in permeate flux recovery between the three different EPS layers were observed. According to the amount of organic carbon remained on the membrane after washing, the magnitude of Psl production provides elevated resistance of the EPS layer to shear stress. The highest flux recovery during the washing stage was observed for the EPS with no Psl. Psl was shown to elevate the layer's shear modulus and shear viscosity but had no effect on the EPS adhesion to the polyamide surface. We conclude that EPS retain on the membrane as a result of the layer viscoelastic properties. These results highlight an important relation between washing efficiency of fouling layers from membranes and their viscoelastic properties, in addition to their adhesion properties.

Original languageEnglish
Pages (from-to)9206-9213
Number of pages8
JournalEnvironmental Science & Technology
Volume50
Issue number17
DOIs
StatePublished - 6 Sep 2016

ASJC Scopus subject areas

  • Chemistry (all)
  • Environmental Chemistry

Fingerprint

Dive into the research topics of 'Viscoelastic properties of extracellular polymeric substances can strongly affect their washing efficiency from reverse osmosis membranes'. Together they form a unique fingerprint.

Cite this