Using factorial experimental design to assess impact of operating conditions on fouling in submerged membrane ultrafiltration system

Abstract

Membrane fouling is a complex phenomena where the diverse nature of water quality necessitates ongoing pilot testing to determine appropriate fouling control strategies. Fouling control strategies are similarly multifold and a factorial experiment is a meaningful method to assess the impact of multiple strategies. This research examined the impact of backwash duration, air sparging flowrate, and relaxation duration by factorial design under both low and high flux conditions using a GE/ZW-1 submerged ultrafiltration membrane. Flux operation and control techniques were independent, that is at low flux the study found that airflow was the predominant factor in controlling fouling, whereas at high flux, interestingly, relaxation was found to be a predominant factor in fouling control. This difference in results highlights the potential importance of altering membrane compression during high flux operations through a relaxation step which can result in a longer membrane operation.

Keywords:

• Hollow fiber membrane
• Fouling
• Modeling
• Submerged
• Membrane cleaning
• Drinking water
• Factorial design

Acknowledgements

The authors would like to thank the Natural Sciences and Engineering Research Council (NSERC) for helping fund this research. The authors would also like to thank GE – Zenon for providing the membranes for the research, as well as Mr. Mohammad Al Rasheedi for his assistance during portions of the experiments.