Fine-pore aeration diffusers: Accelerated membrane ageing studies

An Kaliman, Diego Rosso, Shao Yuan Leu, Michael K. Stenstrom

Research output: Journal article publicationJournal articleAcademic researchpeer-review

22 Citations (Scopus)


Polymeric membranes are widely used in aeration systems for biological treatment. These membranes may degrade over time and are sensitive to fouling and scaling. Membrane degradation is reflected in a decline in operating performance and higher headloss, resulting in increased energy costs. Mechanical property parameters, such as membrane hardness, Young's modulus, and orifice creep, were used to characterize the performance of membranes over time in operation and to predict their failure. Used diffusers from municipal wastewater treatment plants were collected and tested for efficiency and headloss, and then dissected to facilitate measurements of Young's modulus, hardness, and orifice creep. Higher degree of membrane fouling corresponded consistently with larger orifice creep. A lab-scale membrane ageing simulation was performed with polyurethane and four different ethylene-propylene-diene (EPDM) membrane diffusers by subjecting them to chemical ageing cycles and periodic testing. The results confirmed full-scale plant results and showed the superiority of orifice creep over Young's modulus and hardness in predicting diffuser deterioration.
Original languageEnglish
Pages (from-to)467-475
Number of pages9
JournalWater Research
Issue number1-2
Publication statusPublished - 1 Jan 2008
Externally publishedYes


  • Activated sludge
  • Aeration
  • Creep
  • Diffuser
  • Efficiency
  • Membrane

ASJC Scopus subject areas

  • Earth-Surface Processes

Cite this