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

This study focuses on the effect of backwash temperatures (25, 40, and 55 degrees 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 degrees 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 degrees C were more noticeable than those from 40 to 55 degrees C. Overall, backwash at 40 degrees C was relatively a better choice in this study.