Impact of pulsating flows on particle deposition in forward osmosis with spacers

Andreas Kastl, Edo Bar-Zeev, Markus Spinnler, Thomas Sattelmayer

Research output: Contribution to journalArticlepeer-review


Fouling continues to be a limiting factor in membrane processes. Pulsating feed flows have the potential to decrease fouling while maintaining a constant pressure drop over the module. This study quantifies the impact of pulsating flows on particle deposition in a forward osmosis system with spacers at a mean crossflow velocity of 14 cm s−1 and permeate water flux of 18 L m−2 h−1. Carboxylate modified polystyrene beads were tracked by fluorescence microscopy in situ and real-time during the first 4 h of deposition with feed flow pulsations up to a frequency of 10 Hz, while experiments were conducted with a constant crossflow velocity as a reference. Imaging at 30 s intervals revealed deposition rates of up to 2.6 times higher at steady state, as compared to flow pulsations of 10 Hz. Consequentially, average deposition was reduced by a factor of 3.5 from steady state (109 ± 67 beads mm−2) to pulsating feed flow (31 ± 17 beads mm−2) after 4 h of deposition. The results of this research provide new fundamental insights related to the constraints and advantages of using pulsating flows for fouling mitigation in forward osmosis systems.

Original languageAmerican English
Article number119444
JournalJournal of Membrane Science
StatePublished - 1 Oct 2021


  • Forward osmosis
  • Fouling
  • Hydrodynamics
  • Pulsating
  • Spacer

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • General Materials Science
  • Physical and Theoretical Chemistry
  • Filtration and Separation


Dive into the research topics of 'Impact of pulsating flows on particle deposition in forward osmosis with spacers'. Together they form a unique fingerprint.

Cite this