Effects of liquid viscosity on bubble formation characteristics in a typical membrane bioreactor

Shuek Jin Yao Lee, Hui An, Peng Cheng Wang, Joo Guan Hang, Simon Ching Man Yu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

1 Citation (Scopus)


The generation and formation characteristics of air bubbles have significant impact on the performance of the membrane bioreactor system. Experiments were conducted in a tank filled with Glycerine-Water solutions so as to investigate the impacts of liquid viscosity on the bubble formation characteristics. Nozzle size ranging from 2 to 10 mm, air inlet flow rate ranging from 300 to 1500 cc/min and liquid viscosity ranging from 6 to 850 cP have been investigated. Methods to compute the non-linear characteristics such as bubble diameter and bubble rising velocity have been identified. The nonlinear behaviour of the air bubbles were further correlated to the dimensionless numbers such as Reynolds number, Eötvös number and Galilei number. A bubble shape regime was constructed so as to classify the distinct regions of the air bubbles generated from different viscous solutions. Coalescence of bubbles were studied extensively and the impact of liquid viscosity on the bubble flow regimes were presented.

Original languageEnglish
Article number105000
JournalInternational Communications in Heat and Mass Transfer
Publication statusPublished - Jan 2021


  • Bubble formation
  • Bubble shape
  • Dimensionless numbers
  • Shape regime
  • Two-phase flow
  • Viscosity

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Chemical Engineering(all)
  • Condensed Matter Physics

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