Effect of backwash temperature on hollow fiber ultrafiltration membranes fouled by sodium alginate

Abstract

This study focuses on the effect of backwash temperatures (25, 40, and 55°C) on hollow fiber ultrafiltration membranes fouled by sodium alginate (SA). The results indicate that a higher backwash temperature could achieve a significant mitigation of total backwash resistance and a cleaning rate promotion. In the following cycle, the initial total fouling resistance was decreased with the temperature increase, while there was an undesirable increase on the fouling rate due to a higher SA concentration in the membrane pool. Although the membrane fouling resistance was more reversible, backwash at 55°C had a negative impact on the SA removal, because the functional gel layer was washed out. Moreover, all the beneficial effects from 25 to 40°C were more noticeable than those from 40 to 55°C. Overall, backwash at 40°C was relatively a better choice in this study.

Keywords:

• Ultrafiltration
• Sodium alginate
• Backwash temperature
• Hollow fiber membrane
• Total backwash resistance

Acknowledgements

This work was supported by the National Science and Technology Major Project for Water Pollution Control and Treatment (Grant No: 2012ZX07404-003) and the 12th Postgraduate Sci-tech innovation foundation of Beijing University of Technology (No. ykj-2013-10479).